Concord Dependency Seminar Tuesday 23 July 2008 "The Other Hepatitis" - An Update on Hepatitis B. Dr Gail Matthews, St Vincents Hospital Darlinghurst
Summary Part 1. Epidemiology, natural history, assessment.
This seminar was titled The Other Hepatitis, reflecting the lower prevalence of Hepatitis B compared with Hepatitis C among people using addiction treatment services, and the lower profile of HBV in the community.
In contrast to the vigorous response in recent years to hepatitis C (HCV) in Australia, the response to hepatitis B (HBV) has lagged behind, despite important recent developments in understanding of HBV, in diagnostic tests and antiviral treatments, and desite its large disease burden, especially chronic liver disease and liver cancer.
There are many contrasts between HBV and HCV. Whereas HCV in Australia consists of two 'epidemics' - an older group of people born overseas in endemic areas and a younger group of injecting drug users - about half the prevalence of HBV is among Australians born overseas in endemic areas, especially China and SE Asia but also the Middle east and Mediterranean. Only 5% of chronic HBV is among IDUs; another 8% among men who have sex with men (MSM) and a staggering 16% among indigenous Australians.
The picture is different for new infections (incidence) of HBV in Australia: 44% of these happen among IDU (showing the importance of catch-up vaccination for non-immune people in this risk group) and 35% are through sexual transmission, disproportionately among MSM, but the majority still through heterosexual sex.
The total number of people in Australia with chronic HCV is fairly reliably estimated to be between 200,000 and 250,000, while estimates for HBV range more widely between 90,000 and 160,000, reflecting in part poor knowledge of HBV and low levels of testing among some of the high risk groups.
HBV is a DNA virus, where HCV is an RNA virus. HCV is essentially blood-to-blood transmission, particularly by unsafe injecting, and rarely by sexual transmission, while HBV is spread by contact with infected body fluids including blood, semen and saliva. HBV is thus sexually transmitted, but also by vertical transmission (mother to child), horizontally (close personal contact especially in childhood eg cuts, sores) and by IDU.
Of people infected with HCV, 20-30% spontaneously clear the virus, usually within 6 months, and regardless of their age at infection, without however developing immunity (ie they can be reinfected with HCV). Few people develop clinically evident acute hepatitis. By contrast, for HBV progression to chronic infection is strongly related to age at infection: 80-90% of children infected perinatally develop chronic HBV, with lower rates (30%) of chronicity after infection under the age of 5 years; only 6% of older children and adults develop chronic HBV. Most adults who are infected with HBV develop clinically evident acute hepatitis.
Unlike HCV where late clearance of the virus is unknown, a small percentage of people with chronic HBV clear the virus and develop immunity each year.
HBV and HVC are similar in that a subset of people develop chronic liver inflammation which may slowly progress to cirrhosis and liver failure in a minority of cases, and which increases the risk of development of hepatocellular carcinoma (HCC).
The diagnostic tests for HBV, and the natural history of the disease, while rather more complicated than for HCV, have become clearer in recent years. Chronic HBV is now though of as having 4 phases, with gradual progression through the first 2 phases "immune tolerant" and "immunoactive" into the third phase called "immune control" and sometimes progression into a fourth phase called "immune escape".
In the "immune tolerant" phase, there are high levels of HBV-DNA in the blood but little inflammation of the liver (so liver enzymes like ALT are low or normal). The body is not really fighting the virus. This phase is prolonged in people who get HBV perinatally (20 years or more) but is usually much shorter in adult infections.
In the "immunoactive" phase, DNA levels and liver inflammation (ALT) tend to fluctuate. The body is fighting the virus and the liver is in the wars. This can go on for many years, and this is when much of the liver damage from HBV develops.
If the body develops "immune control", viral DNA drops to undetectable levels and the liver function tests normalise. This phase can go on for decades and is associated with no progression of liver disease.
Unfortunately in some people HBV escapes from immune control. In the "immune escape" phase, viral DNA is detectable again and the ALT indicates liver inflammation. People in this phase of HBV often have the most seriously progressive disease.
In making a diagnosis of HBV and working out which phase a person is in, 3 types of tests are used: serological tests, liver function tests (especially ALT for inflammation), and viral DNA measurement (in Australia until recently only specialists could order this expensive test).
There are five commonly used serological tests for HBV. The surface antigen (HBsAg) indicates current Hepatitis B infection. It says "you have hep B now". It is found in serum during the incubation period before symptoms, and persists unless antibodies develop to the surface antigen (anti-HBs). Persistence of HBsAg defines chronic HBV and presence of anti-HBs indicates immunity to HBV infection (either by clearance of surface antigen, or by vaccination). Anti-HBs says "you don't have hep B and you can't get it anymore". * Sometimes anti-HBs wanes to undetectable levels in a person who has immunity to HBV, but there is still immune memory and anti-HBs rises to any immune challenge.
(* but see exceptions below)
The HBV core antibody (anti-HBc) develops early after HBV exposure and generally persists for ever: it just indicates previous exposure, and doesn't imply immunity (in this way it resembles HCV antibody). It says "HBV was here - and may still be here".
There are also tests for the HBV "e" antigen and its antibody (HBeAg and anti-HBe). HBeAg is a marker of viral replication and infectivity, and means there are high levels of HBV DNA in the blood. The person with HBeAg is either in the "immune tolerant" or the "immunoactive" phase of HBV. Loss of the HBeAg with appearance of anti-HBe generally indicates that the HBV DNA levels have been suppressed, the so-called "immune control phase" of hepatitis B - in this case the liver function tests will usually be normal.
However absence of HBeAg and presence of anti-HBe also occurs when a person moves into the "immune escape phase", where HBV-DNA levels and the ALT rise again.
Putting these tests together, HBsAg with HBeAg means chronic HBV with high infectivity. HBsAg with anti-HBe generally means low infectivity, undetectable DNA and "immune control" but can point to "immune escape phase", with high HBV-DNA levels and liver inflammation.
HBV is an oncogenic virus, and unlike HCV, can cause hepatocellular carcinoma (HCC) in the absence of cirrhosis. Of all people with chronic HBV, about 30% will go on to cirrhosis, and 5-10% will go on to HCC. Of people with HBV cirrhosis, about 1 in 4 will go on to liver failure within 5 years.
Numerous factors negatively influence HBV natural history and prognosis: host factors (male gender, older age, obesity and diabetes); viral factors (high viral load, genotype C); coinfection (HIV, HCV, hepatitis D); tobacco smoking and alcohol use. Mortality from liver failure or HCC is much higher when there is HIV coinfection.
Primary prevention for HBV depends on screening and vaccination of high risk individuals and universal vaccination of infants. People who may have poor immune response (HIV/haemodialysis patients) or who may be at higher risk (people with existing liver disease, health care workers) should have anti-HBs checked after the usual 3-vaccine course, and may need a booster. People, including infants, who have accelerated HBV vaccination schedules should also have a booster at 12 months. Immunocompetent people generally do not need boosters even if anti-HBs wanes. However, 5-10% of people fail to respond to vaccination, and these people should be advised that they may need passive vaccination with HBV immunoglobulin (HBIG) within 72 hours if they are exposed to HBV.
HBIG should be given to babies of HBsAg mothers within 12 hrs of delivery, and standard vaccination carried out.
The second part of this summmary will present treatment issues and case studies:
http://www.redfernclinic.com/concord/2008/07/other-hepatitis-update-on-hepatitis-b_31.php4
31 July 2008
"The Other Hepatitis" - An Update on Hepatitis B [PART II]
Concord Dependency Seminar Tuesday 23 July 2008 "The Other Hepatitis" - An Update on Hepatitis B. Dr Gail Matthews, St Vincents Hospital Darlinghurst
Summary Part 2. Treatment issues and case studies.
Dr Matthews pointed out that HBV is a fluctuating disease, and that for the majority, chronic HBV is never "cured". One might wish for HBsAg seroconversion as a goal of treatment, but this currently impracticable. For this reason it is best to think of and manage HBV as a chronic viral illness like HIV, rather than merely a viral hepatitis.
(Note: the majority of adults after acute infection, and a small percentage of people each year after chronic infection, may spontaneously clear HBV by developing anti-HBs. Usually this amounts to spontaneous "cure", however even then HBV can return in situations of immunocompromise eg HIV infection, chemotherapy).
Overall, about 60% of people with HBV can be managed by regular monitoring and attention to risk factors for disease progression, while 40% need antiviral treatment. However, people can move from one group to the other.
The goals of therapy can be defined in several ways, but the essential aim is virological suppression to allow histological improvement, and prevention of HCC and end stage liver disease.
For HBeAg positive individuals, a desirable end-point is anti-HBe seroconversion, with loss of HBeAg. For HBeAg negative individuals, suppression of viral DNA is the essential aim. For all individuals, normalisation of ALT is a good indicator of reduced hepatic injury.
Current therapeutic agents are divided into two types, immune modulators (alpha interferon) and antiviral agents (nucleoside analogues NAs). The development of pegylated interferons and a wider range of NAs has improved therapeutic options and outcomes.
The two main therapeutic questions are: whether to use an immune modulator vs an antiviral; and whether to use one or two agents (immune modulator plus NA, or two NAs).
The benefits of interferon alpha monotherapy for HBeAg positive patients are clear, with reduced rates of cirrhosis and HCC, and increased survival. The treatment aim is to "push" these people into the "immune tolerant" phase of HBV. The advantages of interferon are the finite duration of treatment, durable treatment response (when it occurs), the high rate of HBeAg loss (around 30%), and loss of HBsAg in 3%-8%. Drug resistance does not develop. Disadvantages include unpleasant side effects, high cost, and lower responses with some genotypes and where there is high-level viraemia.
Combination therapy with lamivudine plus interferon alpha for HBeAg positive patients gave higher end of treatment viral response but no higher rates of viral response, eAg seroconversion or sAg seroconversion, compared with interferon alone (Lau et al NEJM 2005).
Nucleoside analogues for HBV include lamivudine, adefovir, entecavir, telbivudine, tenofovir and emtricitabine (the first 4 are currently licensed for HBV). The archetypal NA, lamivudine, effectively suppresses viral replication, with reduced liver inflammation and improved liver histology. In up to 50% of HBeAg positive people, it also produces seroconversion to anti-HBe ("pushing" into the immune control phase) however this may take as long as 5 years. For people who do not achieve eAg seroconversion (ie do not develop anti-HBe) the therapy must be continued indefinitely, as it must also for people who are eAg negative (in the "immune escape" phase).
Unfortunately, viral resistance to lamivudine develops almost universally with time, especially where there is HIV coinfection. In this situation, alternatives are adefovir, and entecavir; the latter is a more potent suppressor of viral replication, and resistance appears to be less of a problem. It may increasingly be first line therapy for many people.
Nucleosides analogues have the advantages of oral delivery with minimal side effects. Treatment is less expensive than interferon, but not when given long-term. There is potential for multidrug resistant organisms, especially when NAs are used sequentially.
Management of chronic HBV depends on a thorough assessment including liver function, serological markers, HBV DNA, sometimes liver biopsy (or fibroscan), and cofactors for disease progression (HCV/HDV/HIV). People should be vaccinated for HAV, given clear advice on transmission, and problems of alcohol, tobacco, obesity and diabetes dealt with if possible.
Specific treatment is recommended for:
• HBeAg positive people who have elevated ALT, and HBV DNA > 20,000 IU/ml
• HBeAg negative people who have abnormal ALT, HBV DNA > 2,000 IU/ml, and necroinflammation/fibrosis on biopsy
• Cirrhotic patients with any level of measurable HBV DNA
Initial Treatment Strategies
Immune modulators may be preferred for healthy people < 60 years, with no cirrhosis, a baseline HBV-DNA > 1010 copies/mL, and ALT > 2-3 times normal, and who have genotype A or B (the more responsive genotypes)
Nucleoside analogs can be used for any age adult, for any genotype, with or without comorbidity (including cirrhosis with or without decompensation), a baseline HBV-DNA 109 copies/mL and ALT > 5 times normal.
In people with advanced HBV it is important to manage the viral infection aggressively and refer early for transplant assessment. Any patient with cirrhosis should have 6-monthly screening for HCC, using alphafetoprotein (AFP) and abdominal ultrasound (in cases of doubt triple phase CT/MRI). The following groups should also be targeted for HCC screening, regardless of their stage of liver disease: Asian men over 40 years of age; Asian women over 50 years of age; Africans over 20 years of age; and people with a family history of HCC.
Case studies (with apologies to Hanna Barbera)
Barnie is 36. He has a 12 year history of heroin injecting, previous buprenorphine maintenance on several occasions usually of short duration and with subsequent relapse His current BMT episode is 5 months, dose 8mg/day and he keeps using heroin.
He says "I've had hep B and hep C for years." He sometimes shares fits because 'What's the point? I've got both already." He drinks alcohol most days, 30-120g.
He is HCV seropositive and HCV-RNApcr positive; HIV negative and HBsAg positive. His ALT is 72, AST 60, GGT and other liver function tests are normal. After strong advice, he ceases sharing injecting paraphernalia, but he continues drinking most days.
On subsequent testing his ALT remains elevated. His second HCV-RNA pcr test is negative. He remains HBsAg positive, HBeAg positive and Anti-HBe negative. How should he be managed?
Comments: if his HCV-RNA remains negative, he may have ceased reinfecting himself with HCV and cleared the virus. He has "immunoactive" HBV with alcohol as a risk factor. Progressive liver fibrosis can occur in the "immunoactive" phase, and alcohol and periods of HCV infection may have contributed to this. Liver biopsy staging may be helpful here. If he does not have cirrhosis already, could have interferon treatment to try to push him into the "immune control" phase of HBV. He should be strongly encouraged and supported to stop alcohol entirely, and this would be a condition for interferon treatment. An alternative would be long term NA treatment.
Fred is 37 and has been on MMT for 6 years. He has not injected drugs for 5 years, and has practically given up alcohol, which he used to drink regularly 30-80g/day. He smokes 40 roll-your-own cigarettes a day.
He is HCV and HIV seronegative but has HBsAg, with both e antibody and antigen. He thinks he got HBV from injecting, but doesn't know when. His ALT and AST are usually normal or mildly elevated (<80) and other liver tests are normal.
During ketoconazole treatment for toenail tinea his transaminases rose to over 500, with other LFTs normal. He stopped the ketoconazole but his transaminases remained elevated (about twice normal) over the next 2 years. He remained positive for HBsAg, and anti-HBe, and became negative for HBeAg.
Fred is against "western" treatment for his liver, and gets herbal treatments from a homeopath in Victoria who runs a telephone consultancy. The cost of these medications ranges up to $60/month plus $60 for each phone consultation. Fred pays the phone bill.
Comments: when he had both Anti-HBe and HBeAg, he was apparently seroconverting for e antigen, thus follow up showed loss of HBeAg. As his transaminases remained elevated, HBV-RNA testing was subsequently done, showing <2,000 IU and confirming "immune escape" phase. He therefore needs long term nucleoside analog treatment. There is no evidence for the benefit of homeopathic treatment, and this should not distract him from the antiviral treatment which he needs to prevent severe liver damage. His smoking is a risk factor for HBV disease progression.
Pebbles is a 32 year old transsexual who is on BMT for heroin addiction. She has always smoked her heroin and never injected drugs. She was born in Asia: her blood tests show anti-HBc and HBsAg but her liver tests are always normal. She says all her family back home have Hep B. She has anti-HBe and does not have the HBeAg. She asks "I am going to get liver cancer?"
Comments: she was probably infected early in life, and is now in the "immune control" phase of HBV. She is at risk of hepatoma even if she remains in the "immune control" phase, and should be screened every six months after the age of 40, or from now if there is a family history of liver cancer. Although it is unlikely she has cirrhosis on this evidence, it is possible. If liver biopsy or fibroscan showed evidence of cirrhosis she should have hepatoma surveillance.
Dino is 38 and is on MMT. He has cleared HCV, is HIV negative and had a full course of HBV vaccination 6 years ago. After a recent test showing negative for anti-HBc, anti-HBs and HBsAg, he had two more HBV shots, but remained anti-HBs negative 6 months later. He asks “What's the point of me having all these tests & these expensive shots if they don't work?"
Comments: 5-10% of people fail to respond to vaccination, and these people should be advised that they may need passive vaccination with HBIG within 72 hours if they are exposed to HBV. HAV vaccination should be offered if he is not immune.
Betty is a 54 year old injecting drug user on MMT with regular alcohol use (40-60g/day most days). She is HCV and HIV seronegative. Her HBV serology is: anti-HBc positive, anti-HBs negative, HBsAg negative, eAg and anti-HBe also negative. Her ALT and AST are always high, with ALT>AST. Should she have HBV-DNA testing?
Comments: with isolated core antibody, it is most likely she has waned surface antibody, and a challenge with a vaccine may demonstrate this with anti-HBs becoming measurable. It is also possible she has chronic HBV and low level HBV-DNA despite not having measurable surface antigen. However, it is unlikely that such low levels of DNA would cause clinically significant disease. HBV-DNA testing is probably not needed but she should be advised to reduce her alcohol to safe levels and liver tests followed up 6-monthly.
Summary Part 2. Treatment issues and case studies.
Dr Matthews pointed out that HBV is a fluctuating disease, and that for the majority, chronic HBV is never "cured". One might wish for HBsAg seroconversion as a goal of treatment, but this currently impracticable. For this reason it is best to think of and manage HBV as a chronic viral illness like HIV, rather than merely a viral hepatitis.
(Note: the majority of adults after acute infection, and a small percentage of people each year after chronic infection, may spontaneously clear HBV by developing anti-HBs. Usually this amounts to spontaneous "cure", however even then HBV can return in situations of immunocompromise eg HIV infection, chemotherapy).
Overall, about 60% of people with HBV can be managed by regular monitoring and attention to risk factors for disease progression, while 40% need antiviral treatment. However, people can move from one group to the other.
The goals of therapy can be defined in several ways, but the essential aim is virological suppression to allow histological improvement, and prevention of HCC and end stage liver disease.
For HBeAg positive individuals, a desirable end-point is anti-HBe seroconversion, with loss of HBeAg. For HBeAg negative individuals, suppression of viral DNA is the essential aim. For all individuals, normalisation of ALT is a good indicator of reduced hepatic injury.
Current therapeutic agents are divided into two types, immune modulators (alpha interferon) and antiviral agents (nucleoside analogues NAs). The development of pegylated interferons and a wider range of NAs has improved therapeutic options and outcomes.
The two main therapeutic questions are: whether to use an immune modulator vs an antiviral; and whether to use one or two agents (immune modulator plus NA, or two NAs).
The benefits of interferon alpha monotherapy for HBeAg positive patients are clear, with reduced rates of cirrhosis and HCC, and increased survival. The treatment aim is to "push" these people into the "immune tolerant" phase of HBV. The advantages of interferon are the finite duration of treatment, durable treatment response (when it occurs), the high rate of HBeAg loss (around 30%), and loss of HBsAg in 3%-8%. Drug resistance does not develop. Disadvantages include unpleasant side effects, high cost, and lower responses with some genotypes and where there is high-level viraemia.
Combination therapy with lamivudine plus interferon alpha for HBeAg positive patients gave higher end of treatment viral response but no higher rates of viral response, eAg seroconversion or sAg seroconversion, compared with interferon alone (Lau et al NEJM 2005).
Nucleoside analogues for HBV include lamivudine, adefovir, entecavir, telbivudine, tenofovir and emtricitabine (the first 4 are currently licensed for HBV). The archetypal NA, lamivudine, effectively suppresses viral replication, with reduced liver inflammation and improved liver histology. In up to 50% of HBeAg positive people, it also produces seroconversion to anti-HBe ("pushing" into the immune control phase) however this may take as long as 5 years. For people who do not achieve eAg seroconversion (ie do not develop anti-HBe) the therapy must be continued indefinitely, as it must also for people who are eAg negative (in the "immune escape" phase).
Unfortunately, viral resistance to lamivudine develops almost universally with time, especially where there is HIV coinfection. In this situation, alternatives are adefovir, and entecavir; the latter is a more potent suppressor of viral replication, and resistance appears to be less of a problem. It may increasingly be first line therapy for many people.
Nucleosides analogues have the advantages of oral delivery with minimal side effects. Treatment is less expensive than interferon, but not when given long-term. There is potential for multidrug resistant organisms, especially when NAs are used sequentially.
Management of chronic HBV depends on a thorough assessment including liver function, serological markers, HBV DNA, sometimes liver biopsy (or fibroscan), and cofactors for disease progression (HCV/HDV/HIV). People should be vaccinated for HAV, given clear advice on transmission, and problems of alcohol, tobacco, obesity and diabetes dealt with if possible.
Specific treatment is recommended for:
• HBeAg positive people who have elevated ALT, and HBV DNA > 20,000 IU/ml
• HBeAg negative people who have abnormal ALT, HBV DNA > 2,000 IU/ml, and necroinflammation/fibrosis on biopsy
• Cirrhotic patients with any level of measurable HBV DNA
Initial Treatment Strategies
Immune modulators may be preferred for healthy people < 60 years, with no cirrhosis, a baseline HBV-DNA > 1010 copies/mL, and ALT > 2-3 times normal, and who have genotype A or B (the more responsive genotypes)
Nucleoside analogs can be used for any age adult, for any genotype, with or without comorbidity (including cirrhosis with or without decompensation), a baseline HBV-DNA 109 copies/mL and ALT > 5 times normal.
In people with advanced HBV it is important to manage the viral infection aggressively and refer early for transplant assessment. Any patient with cirrhosis should have 6-monthly screening for HCC, using alphafetoprotein (AFP) and abdominal ultrasound (in cases of doubt triple phase CT/MRI). The following groups should also be targeted for HCC screening, regardless of their stage of liver disease: Asian men over 40 years of age; Asian women over 50 years of age; Africans over 20 years of age; and people with a family history of HCC.
Case studies (with apologies to Hanna Barbera)
Barnie is 36. He has a 12 year history of heroin injecting, previous buprenorphine maintenance on several occasions usually of short duration and with subsequent relapse His current BMT episode is 5 months, dose 8mg/day and he keeps using heroin.
He says "I've had hep B and hep C for years." He sometimes shares fits because 'What's the point? I've got both already." He drinks alcohol most days, 30-120g.
He is HCV seropositive and HCV-RNApcr positive; HIV negative and HBsAg positive. His ALT is 72, AST 60, GGT and other liver function tests are normal. After strong advice, he ceases sharing injecting paraphernalia, but he continues drinking most days.
On subsequent testing his ALT remains elevated. His second HCV-RNA pcr test is negative. He remains HBsAg positive, HBeAg positive and Anti-HBe negative. How should he be managed?
Comments: if his HCV-RNA remains negative, he may have ceased reinfecting himself with HCV and cleared the virus. He has "immunoactive" HBV with alcohol as a risk factor. Progressive liver fibrosis can occur in the "immunoactive" phase, and alcohol and periods of HCV infection may have contributed to this. Liver biopsy staging may be helpful here. If he does not have cirrhosis already, could have interferon treatment to try to push him into the "immune control" phase of HBV. He should be strongly encouraged and supported to stop alcohol entirely, and this would be a condition for interferon treatment. An alternative would be long term NA treatment.
Fred is 37 and has been on MMT for 6 years. He has not injected drugs for 5 years, and has practically given up alcohol, which he used to drink regularly 30-80g/day. He smokes 40 roll-your-own cigarettes a day.
He is HCV and HIV seronegative but has HBsAg, with both e antibody and antigen. He thinks he got HBV from injecting, but doesn't know when. His ALT and AST are usually normal or mildly elevated (<80) and other liver tests are normal.
During ketoconazole treatment for toenail tinea his transaminases rose to over 500, with other LFTs normal. He stopped the ketoconazole but his transaminases remained elevated (about twice normal) over the next 2 years. He remained positive for HBsAg, and anti-HBe, and became negative for HBeAg.
Fred is against "western" treatment for his liver, and gets herbal treatments from a homeopath in Victoria who runs a telephone consultancy. The cost of these medications ranges up to $60/month plus $60 for each phone consultation. Fred pays the phone bill.
Comments: when he had both Anti-HBe and HBeAg, he was apparently seroconverting for e antigen, thus follow up showed loss of HBeAg. As his transaminases remained elevated, HBV-RNA testing was subsequently done, showing <2,000 IU and confirming "immune escape" phase. He therefore needs long term nucleoside analog treatment. There is no evidence for the benefit of homeopathic treatment, and this should not distract him from the antiviral treatment which he needs to prevent severe liver damage. His smoking is a risk factor for HBV disease progression.
Pebbles is a 32 year old transsexual who is on BMT for heroin addiction. She has always smoked her heroin and never injected drugs. She was born in Asia: her blood tests show anti-HBc and HBsAg but her liver tests are always normal. She says all her family back home have Hep B. She has anti-HBe and does not have the HBeAg. She asks "I am going to get liver cancer?"
Comments: she was probably infected early in life, and is now in the "immune control" phase of HBV. She is at risk of hepatoma even if she remains in the "immune control" phase, and should be screened every six months after the age of 40, or from now if there is a family history of liver cancer. Although it is unlikely she has cirrhosis on this evidence, it is possible. If liver biopsy or fibroscan showed evidence of cirrhosis she should have hepatoma surveillance.
Dino is 38 and is on MMT. He has cleared HCV, is HIV negative and had a full course of HBV vaccination 6 years ago. After a recent test showing negative for anti-HBc, anti-HBs and HBsAg, he had two more HBV shots, but remained anti-HBs negative 6 months later. He asks “What's the point of me having all these tests & these expensive shots if they don't work?"
Comments: 5-10% of people fail to respond to vaccination, and these people should be advised that they may need passive vaccination with HBIG within 72 hours if they are exposed to HBV. HAV vaccination should be offered if he is not immune.
Betty is a 54 year old injecting drug user on MMT with regular alcohol use (40-60g/day most days). She is HCV and HIV seronegative. Her HBV serology is: anti-HBc positive, anti-HBs negative, HBsAg negative, eAg and anti-HBe also negative. Her ALT and AST are always high, with ALT>AST. Should she have HBV-DNA testing?
Comments: with isolated core antibody, it is most likely she has waned surface antibody, and a challenge with a vaccine may demonstrate this with anti-HBs becoming measurable. It is also possible she has chronic HBV and low level HBV-DNA despite not having measurable surface antigen. However, it is unlikely that such low levels of DNA would cause clinically significant disease. HBV-DNA testing is probably not needed but she should be advised to reduce her alcohol to safe levels and liver tests followed up 6-monthly.
22 July 2008
Adult ADHD & Substance Use Disorders – Dr Julian Trollor
Concord Dependency Seminar Tuesday 22nd July 2008
Adult ADHD & Substance Use Disorders – Dr Julian Trollor
Dr Julian Trollor is Senior Staff Specialist Neuropsychiatrist at the Neuropsychiatric Institute, Prince of Wales Hospital and Senior Research Fellow of the Brain Ageing Program at the University of New South Wales. He established a clinic for the assessment of adults with possible ADHD in 1995. This clinic now operates as a tertiary service, providing second opinions in difficult cases.
Dr Trollor began his presentation by recounting his own experience of filling out a pop-up box which once appeared unbidden on his computer screen. Dr Trollor (who does not have ADHD) was informed...."the responses you have provided indicate that your symptoms may be consistent with Adult ADD. It may be beneficial for you to talk with your healthcare professional about an evaluation.” The pop-up was sponsored by a manufacturer of a pharmaceutical for ADHD.
Dr Trollor pointed to the growing popular awareness of Adult ADHD (A-ADHD), with ‘self diagnosis’ being common, shared controversy with its childhood counterpart, and community fears about treatment with a potential "drug of abuse".
ADHD is a "neurodevelopmental disorder of childhood onset characterised by impairments in cognitive function (inattentiveness), excessive motor behaviour (hyperactivity) and impaired behavioural regulation (impulsivity).” It is common, with high co-morbidity, and it is often overlooked, despite being relatively easily treated, with treatment improving outcomes.
Evidence for the validity of the entity A-ADHD has increased greatly in the last decade and is found in cross sectional, longitudinal and epidemiological studies, family & genetic studies, and neuro-psychological, -physiological, -endocrine and -anatomical studies.
Despite progress in understanding of A-ADHD, clinical diagnosis remains problematic: there is no single criterion marker; the core symptoms are dimensional (or spectrum) rather than categorical; co-morbidity can confound diagnosis; the requirement for retrospective childhood diagnosis may create difficulties; the key descriptors are ubiquitous; and the requirement for “significant impairment” is arbitrary. Diagnostic tests are often used but they lack specificity.
The DSM IV CRITERIA are listed in the appendix (see Redfern Clinic website). Briefly, the person must have (for the primarily inattentive type) six or more inattention symptoms as well as (for the combined type) six or more hyperactivity/impulsivity items for at least 6 months to a degree that is maladaptive. Some symptoms must be present before 7 years of age, impairment must be present in at least two settings, and symptoms do not occur exclusively during the course of a pervasive developmental disorder, psychotic disorder and (as always in DSM-IV) are not better accounted for by another mental disorder.
Symptoms can be grouped in four types:
1. attentional, with difficulty sustaining attention (during lectures, reading, in conversation, at work), easily distractability (eg by extraneous sounds, activity), day-dreaming, making careless mistakes - the primarily inattentional type is more common among women.
2. organisational, often losing things, forgetting day to day activities or appointments, having difficulty organising tasks, following verbal instructions - these may be more pronounced in unstructured settings, and therefore may become more problematic in adults, upon leaving a structured setting like school/college.
3. hyperactivity, being always “on the go” physically, being fidgety or restless, having difficulty relaxing, having racing thoughts or many ideas, taking on multiple tasks at once without finishing many.
4. impulsivity, talking excessively, making tactless comments, interrupting conversations, difficulty waiting turn, taking risks (eg driving, thrill seeking, financial risks), explosive temper, irritated easily by minor frustrations, quick mood changes.
Hyperactivity may be less marked in adults in whom the hyperactivity may be more a phenomenon of mental cluttering, akin to a sense of continuous "noise" - quite distinct from anxiety. A meta-analysis of follow-up studies of children with ADHD showed an age-dependent decline in ADHD symptoms: 65% experienced partial remission in adulthood, with full ADHD diagnosis persisting in approximately 15%. The severity of ADHD symptoms in childhood appears to predict persistence into adulthood.
A large cross-national survey estimated adult ADHD prevalence across ten countries to be 3.4% (range 1.2-7.3%); one US study estimated current prevalence of adult ADHD at 4.4%. As Dr Trollor pointed out, these estimates suggest that A-ADHD is one of the more common mental disorders.
ADHD is a condition with a high genetic loading - family studies suggest 80% of ADHD symptoms can be attributed to genetic factors - with genetic-environmental interactions also playing a role, especially disrupted attachment, early abuse, and chaotic environment. The candidate genes are those involved in motor activity and attentional processes, and include DAT gene (SLC6A3), COMT (Catechol-O-methyltransferase), DBH (Dopamine beta-hydroxylase) and dopamine receptors (especially DRD4), however no single gene accounts for more than 5% of the phenotypic variance of ADHD.
Adult ADHD has major consequences: adults with ADHD are less likely to be employed full-time and more likely to have unstable work records, have significantly lower household income, have fewer close friends, more difficulty sustaining relationships and higher likelihood of having contracted a sexually transmitted disease. They are more accident prone (more traffic violations, severe accidents, more likely to be ‘at fault’), and have higher medical costs.
Diagnosis
In making a diagnosis, it is important to consider the motive/catalyst for presentation, whether owing to legal & forensic issues, a transition from a more to a less structured environment, or on cessation of substance use. Some adults come forward for assessment following diagnosis of their children. Self diagnosis is not a reliable indicator of the presence or absence of ADHD
The diagnostic pathway is to assess current symptom profile, severity and impact, to establish and corroborate childhood diagnosis (from self-report, parental and school reports, previous psychological or medical assessments) and to evaluate co-morbid (or diagnostically confounding) conditions - people with ADHD have increased risk of a diagnosis of antisocial personality disorder, of anxiety disorders, major depression and substance use disorders.
Bearing in mind the partial remission of ADHD in many or even most adults, it is important to consider the actual impact of symptoms on the patient's social, occupational, educational or family life as well as their current coping strategies. Many people cope well with or are untroubled by having features of ADHD and it is not uncommon for people with ADHD to be less likely to complain than their partners or family.
Establishing a retrospective childhood diagnosis is often a challenge, especially for people with major psychosocial problems including substance use disorder (SUD) who may have chaotic histories and be estranged from family. Where possible, informant interview can provide corroboration of the nature and extent of both current and past symptoms. Evidence can be gleaned from academic records, number and type of jobs, history of impulsive infringements, self esteem and interpersonal problems (resulting from impulsivity, poor anger control and organisational skills), and patterns of drug use which may suggest self-medication of symptoms. Sometimes there is a suggestive ‘paradoxical response’ to street amphetamine - ie a calming effect rather than stimulation.
Further assessment may include the use of rating scales, and require physical examination, bloods testing including thyroid function, urine toxicology, EEG, CT/MRI of the brain (a history of head injury may be common in people ADHD owing to their accident proneness, but brain injury may also sometimes mimic ADHD symptoms), and neuropsychological examination including CPT. Not all of these will be required in every case.
Substance Use Disorders and A-ADHD
The epidemiological relationship between substance use disorders (SUD) and A-ADHD is bi-directional, with increased rates of SUD in ADHD clinic samples (for alcohol 17-45%, other drugs 9-30%) and of ADHD in SUD clinic samples (around 25%).
Relative risk of SUD in follow-up of ADHD cohorts is increased up to five-fold, with earlier and increased use of alcohol, tobacco and other substances in adolescents with ADHD compared to controls, and ADHD in childhood and adolescence a significant predictor for later substance use - the risk is greater if the individual has conduct disorder or mood disorder. The relationship of with childhood ADHD is strongest for tobacco smoking, and it is likely a sub-group of individuals with ADHD self-medicate with tobacco: nicotine has been successfully trialled as an intervention.
People who have both SUD and ADHD have poorer outcomes. However, people treated with stimulants in childhood and/or adolescence have an equivalent or lower incidence of SUD compared to those untreated, and the use of stimulant medication to treat people with ADHD does not increase the risk of developing substance use disorder.
It is preferable to perform diagnostic assessment during long-term abstinence (whereby opioid substitution treatment with abstinence from other problematic substance use can be considered abstinence) and, as with other co-morbidities, active SUD should be addressed prior to specific ADHD treatment. It should be borne in mind that ADHD medications have no demonstrated efficacy for the treatment of ADHD where there is co-morbid SUD, nor have studies been conducted of use of psychosocial interventions.
Dr Trollor recommended (and feedback is welcome about) the Draft Guidelines for the Assessment and Management of Attention Deficit Hyperactivity Disorder (National Health and Medical Research Council and the Royal Australasian College of Physicians) accessible at http://www.racp.edu.au/ ( follow link under ‘announcements’).
From these guidelines, the following are some key recommendations for best practice for assessment and diagnosis of ADHD in adults when co-morbid SUD is present:
People with personality disorder and/or substance abuse should be referred for evaluation of ADHD if they present with a significant level of hyperactivity / impulsivity accompanied by inattention.
Medication treatment for ADHD co-morbid with substance misuse should only be provided by a medical practitioner with expertise in both conditions.
ATX should be the first medication trialled if there is co-morbid substance abuse.
Management of A-ADHD
Dr Trollor's approach to management is to create a hierarchy for interventions, generally treating pressing co-morbid conditions first, as these may increase the expression of ADHD symptoms, and providing for further observation in cases where the diagnosis is uncertain.
Specific A-ADHD treatments include: education (through internet, books, support groups); drug therapies (methylphenidate 0.3-1.0mg/kd/day; dextroamphetamine 0.2-0.5mg/kg/day, desipramine, imipramine 25-100mg; and others including atomoxetine, buproprion, MAOI, lithium, venlafaxine, SSRI, CBZ, clonidine,); cognitive & other behavioural therapies to increase organisational skills, impulse control, and self monitoring.
Psychostimulants
Against a backdrop of a rapid rise in prescription rates, unease about use of stimulants arises from several considerations. With continuation of treatment from childhood there are potentially decades of exposure to stimulants. Should this be open-ended? What are the risks of psychological dependence, and harmful use/dependence given the high psychosocial and substance comorbidity in adults with ADHD?
Stimulants are effective in adults with ADHD although the number of studies is small. Available efficacy data for adults give response rates between 25 and 78 percent for methylphenidate (MPH), in a similar dose range as for children, and a modest literature suggest similar efficacy for dexamphetamine (DEX) - there is no direct evidence to support use of high or very high doses of MPH or DEX.
Current evidence suggests the use of stimulant medication to treat people, including children, with ADHD does not increase the risk of developing substance use disorder. However, there is evidence of diversion and misuse of prescription medications for ADHD among school students and college students, with between 16 and 29 percent of students on stimulant medication having been asked to give, sell or trade their medication at some time. While some individuals report using diverted stimulants to self-medicate for ADHD symptoms, others use them to enhance performance, or for their euphorogenic effects.
Dr Trollor advises stimulant treatment should be reserved for people with pervasive symptoms causing significant difficulty, and where clear goals can be identified, the patient is motivated to work on broad range of solutions and where adequate follow-up and monitoring is available.
Stimulant treatment is relatively contraindicated where ADHD symptoms are present but are not the primary problem, where the clinical diagnosis conflicts with patient ‘self-diagnosis’, where there is severe co-morbid psychosis or mood disorder, or continuing problematic substance use. One warning signal is where the patient has many past prescribers of stimulants.
Non-stimulants, long-acting stimulants or anti-depressants are preferred to short acting stimulants, which are strongly reinforcing drugs. Pharmacotherapy should be trialled for effectiveness on an individual basis and carefully monitored for benefits and adverse effects; a contract for stimulant treatment may include regular review (possibly including urine toxicology - a moot point at this seminar) and an ongoing goal of abstinence.
Atomoxetine is a predominantly presynaptic noradrenaline transporter inhibitor without euphorigenic and reinforcing properties, with several studies showing benefit in children and adults. There is also a small number of studies for buproprion (an indirect NA & DA agonist), likewise with a low “abuse potential”.
Stimulant Dose
There are no trials of ‘high’ or ‘very high’ stimulant doses in adults with ADHD, and low dosing appears to be appropriate for most individuals. Dr Trollor recommends cautious titration eg commencing at DEX 0.15mg/kg/day or MPH 0.3mg/kg/day and aiming for DEX < 0.5mg/kg/day or MPH <1.0mg/kg/day. For the stimulant-naive patient, Dr Trollor recommends commencing DEX 5mg mane & midi (or MPH 10mg mane & midi). Smaller doses may also be required if patient on other psychotropics or has comorbid anxiety or sleep disorder. Animal models demonstrate a biphasic response to DEX: low doses (DEX < 1.0mg/kg) reduce, and higher doses DEX 1.0-5.0mg/kg increase, locomotor activity, which may correspond to a “high” in humans. As stimulants lower the seizure threshold in animals, are associated with (transient) emergent ‘tics’ in 10% of stimulant treated children, elevate pulse and blood pressure (low dose stimulants increase BP by an average of 3-5mmHg) low doses and close monitoring are indicated where there is co-morbid tic disorder, hypertension or seizure disorder. Although psycho-stimulants can induce paranoid delusions, auditory & visual hallucinations, this is mainly seen with intravenous use. Inter-individual pharmacokinetic variability (especially for MPH, where peak serum levels vary up to five-fold) provides an argument for a trial of higher doses in some individuals with non response to low doses - monitoring stimulant levels may be helpful, as may a second opinion. One difficulty is how to monitor response, whether subjectively or using self rating scales, observer rating scales, or neuropsychological/neurophysiological testing. Many people will feel better using low dose stimulants, regardless of whether they have ADHD or not.
This conundrum was illustrated in a complex case study presented in the second half (see separate posting). Some parting questions: how can such a prevalent condition, especially in children, be conceived of as a disorder? In an evolutionary sense, does ADHD confer an individual or collective biological advantage? In an anthropological sense, does it represent a failure of adaptation to modern life? Summary by Richard Hallinan, based on Dr Trollor's presentation and powerpoint file.
Clinic web page: http://www.redfernclinic.com/#news
Concord Seminar blog: http://concorddependency.blogspot.com/
Adult ADHD & Substance Use Disorders – Dr Julian Trollor
Dr Julian Trollor is Senior Staff Specialist Neuropsychiatrist at the Neuropsychiatric Institute, Prince of Wales Hospital and Senior Research Fellow of the Brain Ageing Program at the University of New South Wales. He established a clinic for the assessment of adults with possible ADHD in 1995. This clinic now operates as a tertiary service, providing second opinions in difficult cases.
Dr Trollor began his presentation by recounting his own experience of filling out a pop-up box which once appeared unbidden on his computer screen. Dr Trollor (who does not have ADHD) was informed...."the responses you have provided indicate that your symptoms may be consistent with Adult ADD. It may be beneficial for you to talk with your healthcare professional about an evaluation.” The pop-up was sponsored by a manufacturer of a pharmaceutical for ADHD.
Dr Trollor pointed to the growing popular awareness of Adult ADHD (A-ADHD), with ‘self diagnosis’ being common, shared controversy with its childhood counterpart, and community fears about treatment with a potential "drug of abuse".
ADHD is a "neurodevelopmental disorder of childhood onset characterised by impairments in cognitive function (inattentiveness), excessive motor behaviour (hyperactivity) and impaired behavioural regulation (impulsivity).” It is common, with high co-morbidity, and it is often overlooked, despite being relatively easily treated, with treatment improving outcomes.
Evidence for the validity of the entity A-ADHD has increased greatly in the last decade and is found in cross sectional, longitudinal and epidemiological studies, family & genetic studies, and neuro-psychological, -physiological, -endocrine and -anatomical studies.
Despite progress in understanding of A-ADHD, clinical diagnosis remains problematic: there is no single criterion marker; the core symptoms are dimensional (or spectrum) rather than categorical; co-morbidity can confound diagnosis; the requirement for retrospective childhood diagnosis may create difficulties; the key descriptors are ubiquitous; and the requirement for “significant impairment” is arbitrary. Diagnostic tests are often used but they lack specificity.
The DSM IV CRITERIA are listed in the appendix (see Redfern Clinic website). Briefly, the person must have (for the primarily inattentive type) six or more inattention symptoms as well as (for the combined type) six or more hyperactivity/impulsivity items for at least 6 months to a degree that is maladaptive. Some symptoms must be present before 7 years of age, impairment must be present in at least two settings, and symptoms do not occur exclusively during the course of a pervasive developmental disorder, psychotic disorder and (as always in DSM-IV) are not better accounted for by another mental disorder.
Symptoms can be grouped in four types:
1. attentional, with difficulty sustaining attention (during lectures, reading, in conversation, at work), easily distractability (eg by extraneous sounds, activity), day-dreaming, making careless mistakes - the primarily inattentional type is more common among women.
2. organisational, often losing things, forgetting day to day activities or appointments, having difficulty organising tasks, following verbal instructions - these may be more pronounced in unstructured settings, and therefore may become more problematic in adults, upon leaving a structured setting like school/college.
3. hyperactivity, being always “on the go” physically, being fidgety or restless, having difficulty relaxing, having racing thoughts or many ideas, taking on multiple tasks at once without finishing many.
4. impulsivity, talking excessively, making tactless comments, interrupting conversations, difficulty waiting turn, taking risks (eg driving, thrill seeking, financial risks), explosive temper, irritated easily by minor frustrations, quick mood changes.
Hyperactivity may be less marked in adults in whom the hyperactivity may be more a phenomenon of mental cluttering, akin to a sense of continuous "noise" - quite distinct from anxiety. A meta-analysis of follow-up studies of children with ADHD showed an age-dependent decline in ADHD symptoms: 65% experienced partial remission in adulthood, with full ADHD diagnosis persisting in approximately 15%. The severity of ADHD symptoms in childhood appears to predict persistence into adulthood.
A large cross-national survey estimated adult ADHD prevalence across ten countries to be 3.4% (range 1.2-7.3%); one US study estimated current prevalence of adult ADHD at 4.4%. As Dr Trollor pointed out, these estimates suggest that A-ADHD is one of the more common mental disorders.
ADHD is a condition with a high genetic loading - family studies suggest 80% of ADHD symptoms can be attributed to genetic factors - with genetic-environmental interactions also playing a role, especially disrupted attachment, early abuse, and chaotic environment. The candidate genes are those involved in motor activity and attentional processes, and include DAT gene (SLC6A3), COMT (Catechol-O-methyltransferase), DBH (Dopamine beta-hydroxylase) and dopamine receptors (especially DRD4), however no single gene accounts for more than 5% of the phenotypic variance of ADHD.
Adult ADHD has major consequences: adults with ADHD are less likely to be employed full-time and more likely to have unstable work records, have significantly lower household income, have fewer close friends, more difficulty sustaining relationships and higher likelihood of having contracted a sexually transmitted disease. They are more accident prone (more traffic violations, severe accidents, more likely to be ‘at fault’), and have higher medical costs.
Diagnosis
In making a diagnosis, it is important to consider the motive/catalyst for presentation, whether owing to legal & forensic issues, a transition from a more to a less structured environment, or on cessation of substance use. Some adults come forward for assessment following diagnosis of their children. Self diagnosis is not a reliable indicator of the presence or absence of ADHD
The diagnostic pathway is to assess current symptom profile, severity and impact, to establish and corroborate childhood diagnosis (from self-report, parental and school reports, previous psychological or medical assessments) and to evaluate co-morbid (or diagnostically confounding) conditions - people with ADHD have increased risk of a diagnosis of antisocial personality disorder, of anxiety disorders, major depression and substance use disorders.
Bearing in mind the partial remission of ADHD in many or even most adults, it is important to consider the actual impact of symptoms on the patient's social, occupational, educational or family life as well as their current coping strategies. Many people cope well with or are untroubled by having features of ADHD and it is not uncommon for people with ADHD to be less likely to complain than their partners or family.
Establishing a retrospective childhood diagnosis is often a challenge, especially for people with major psychosocial problems including substance use disorder (SUD) who may have chaotic histories and be estranged from family. Where possible, informant interview can provide corroboration of the nature and extent of both current and past symptoms. Evidence can be gleaned from academic records, number and type of jobs, history of impulsive infringements, self esteem and interpersonal problems (resulting from impulsivity, poor anger control and organisational skills), and patterns of drug use which may suggest self-medication of symptoms. Sometimes there is a suggestive ‘paradoxical response’ to street amphetamine - ie a calming effect rather than stimulation.
Further assessment may include the use of rating scales, and require physical examination, bloods testing including thyroid function, urine toxicology, EEG, CT/MRI of the brain (a history of head injury may be common in people ADHD owing to their accident proneness, but brain injury may also sometimes mimic ADHD symptoms), and neuropsychological examination including CPT. Not all of these will be required in every case.
Substance Use Disorders and A-ADHD
The epidemiological relationship between substance use disorders (SUD) and A-ADHD is bi-directional, with increased rates of SUD in ADHD clinic samples (for alcohol 17-45%, other drugs 9-30%) and of ADHD in SUD clinic samples (around 25%).
Relative risk of SUD in follow-up of ADHD cohorts is increased up to five-fold, with earlier and increased use of alcohol, tobacco and other substances in adolescents with ADHD compared to controls, and ADHD in childhood and adolescence a significant predictor for later substance use - the risk is greater if the individual has conduct disorder or mood disorder. The relationship of with childhood ADHD is strongest for tobacco smoking, and it is likely a sub-group of individuals with ADHD self-medicate with tobacco: nicotine has been successfully trialled as an intervention.
People who have both SUD and ADHD have poorer outcomes. However, people treated with stimulants in childhood and/or adolescence have an equivalent or lower incidence of SUD compared to those untreated, and the use of stimulant medication to treat people with ADHD does not increase the risk of developing substance use disorder.
It is preferable to perform diagnostic assessment during long-term abstinence (whereby opioid substitution treatment with abstinence from other problematic substance use can be considered abstinence) and, as with other co-morbidities, active SUD should be addressed prior to specific ADHD treatment. It should be borne in mind that ADHD medications have no demonstrated efficacy for the treatment of ADHD where there is co-morbid SUD, nor have studies been conducted of use of psychosocial interventions.
Dr Trollor recommended (and feedback is welcome about) the Draft Guidelines for the Assessment and Management of Attention Deficit Hyperactivity Disorder (National Health and Medical Research Council and the Royal Australasian College of Physicians) accessible at http://www.racp.edu.au/ ( follow link under ‘announcements’).
From these guidelines, the following are some key recommendations for best practice for assessment and diagnosis of ADHD in adults when co-morbid SUD is present:
People with personality disorder and/or substance abuse should be referred for evaluation of ADHD if they present with a significant level of hyperactivity / impulsivity accompanied by inattention.
Medication treatment for ADHD co-morbid with substance misuse should only be provided by a medical practitioner with expertise in both conditions.
ATX should be the first medication trialled if there is co-morbid substance abuse.
Management of A-ADHD
Dr Trollor's approach to management is to create a hierarchy for interventions, generally treating pressing co-morbid conditions first, as these may increase the expression of ADHD symptoms, and providing for further observation in cases where the diagnosis is uncertain.
Specific A-ADHD treatments include: education (through internet, books, support groups); drug therapies (methylphenidate 0.3-1.0mg/kd/day; dextroamphetamine 0.2-0.5mg/kg/day, desipramine, imipramine 25-100mg; and others including atomoxetine, buproprion, MAOI, lithium, venlafaxine, SSRI, CBZ, clonidine,); cognitive & other behavioural therapies to increase organisational skills, impulse control, and self monitoring.
Psychostimulants
Against a backdrop of a rapid rise in prescription rates, unease about use of stimulants arises from several considerations. With continuation of treatment from childhood there are potentially decades of exposure to stimulants. Should this be open-ended? What are the risks of psychological dependence, and harmful use/dependence given the high psychosocial and substance comorbidity in adults with ADHD?
Stimulants are effective in adults with ADHD although the number of studies is small. Available efficacy data for adults give response rates between 25 and 78 percent for methylphenidate (MPH), in a similar dose range as for children, and a modest literature suggest similar efficacy for dexamphetamine (DEX) - there is no direct evidence to support use of high or very high doses of MPH or DEX.
Current evidence suggests the use of stimulant medication to treat people, including children, with ADHD does not increase the risk of developing substance use disorder. However, there is evidence of diversion and misuse of prescription medications for ADHD among school students and college students, with between 16 and 29 percent of students on stimulant medication having been asked to give, sell or trade their medication at some time. While some individuals report using diverted stimulants to self-medicate for ADHD symptoms, others use them to enhance performance, or for their euphorogenic effects.
Dr Trollor advises stimulant treatment should be reserved for people with pervasive symptoms causing significant difficulty, and where clear goals can be identified, the patient is motivated to work on broad range of solutions and where adequate follow-up and monitoring is available.
Stimulant treatment is relatively contraindicated where ADHD symptoms are present but are not the primary problem, where the clinical diagnosis conflicts with patient ‘self-diagnosis’, where there is severe co-morbid psychosis or mood disorder, or continuing problematic substance use. One warning signal is where the patient has many past prescribers of stimulants.
Non-stimulants, long-acting stimulants or anti-depressants are preferred to short acting stimulants, which are strongly reinforcing drugs. Pharmacotherapy should be trialled for effectiveness on an individual basis and carefully monitored for benefits and adverse effects; a contract for stimulant treatment may include regular review (possibly including urine toxicology - a moot point at this seminar) and an ongoing goal of abstinence.
Atomoxetine is a predominantly presynaptic noradrenaline transporter inhibitor without euphorigenic and reinforcing properties, with several studies showing benefit in children and adults. There is also a small number of studies for buproprion (an indirect NA & DA agonist), likewise with a low “abuse potential”.
Stimulant Dose
There are no trials of ‘high’ or ‘very high’ stimulant doses in adults with ADHD, and low dosing appears to be appropriate for most individuals. Dr Trollor recommends cautious titration eg commencing at DEX 0.15mg/kg/day or MPH 0.3mg/kg/day and aiming for DEX < 0.5mg/kg/day or MPH <1.0mg/kg/day. For the stimulant-naive patient, Dr Trollor recommends commencing DEX 5mg mane & midi (or MPH 10mg mane & midi). Smaller doses may also be required if patient on other psychotropics or has comorbid anxiety or sleep disorder. Animal models demonstrate a biphasic response to DEX: low doses (DEX < 1.0mg/kg) reduce, and higher doses DEX 1.0-5.0mg/kg increase, locomotor activity, which may correspond to a “high” in humans. As stimulants lower the seizure threshold in animals, are associated with (transient) emergent ‘tics’ in 10% of stimulant treated children, elevate pulse and blood pressure (low dose stimulants increase BP by an average of 3-5mmHg) low doses and close monitoring are indicated where there is co-morbid tic disorder, hypertension or seizure disorder. Although psycho-stimulants can induce paranoid delusions, auditory & visual hallucinations, this is mainly seen with intravenous use. Inter-individual pharmacokinetic variability (especially for MPH, where peak serum levels vary up to five-fold) provides an argument for a trial of higher doses in some individuals with non response to low doses - monitoring stimulant levels may be helpful, as may a second opinion. One difficulty is how to monitor response, whether subjectively or using self rating scales, observer rating scales, or neuropsychological/neurophysiological testing. Many people will feel better using low dose stimulants, regardless of whether they have ADHD or not.
This conundrum was illustrated in a complex case study presented in the second half (see separate posting). Some parting questions: how can such a prevalent condition, especially in children, be conceived of as a disorder? In an evolutionary sense, does ADHD confer an individual or collective biological advantage? In an anthropological sense, does it represent a failure of adaptation to modern life? Summary by Richard Hallinan, based on Dr Trollor's presentation and powerpoint file.
Clinic web page: http://www.redfernclinic.com/#news
Concord Seminar blog: http://concorddependency.blogspot.com/
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