Initiation of Methamphetamine Abuse During Interferon Treatment

To The Editor: Interferon therapy for chronic infection with hepatitis B or hepatitis C virus produces clinical depression in up to one-half of patients treated. Adverse effects of interferon increase the risk of relapse to opiate and cocaine use during therapy in former injection drug users, which may in turn reduce the likelihood of achieving a sustained virologic response (1 – 3) . To reduce the risk of relapse, interferon therapeutic guidelines stress the importance of pretreatment assessment of all patients for anxiety, depression, and substance abuse disorders (4) . We report the case of an additional and previously undocumented risk during interferon treatment: initiation of crystal methamphetamine abuse.

The increased risk of relapse to substance abuse during interferon therapy is widely appreciated. Our case alerts clinicians to the initiation and progressive use of methamphetamine during interferon therapy, a previously undocumented risk. Patients experiencing interferon-induced depression may find the acute methamphetamine-induced increases in monoamines (principally dopamine) alluring (5) .

In the United States, Canada, and Australia, the prevalence of occasional methamphetamine use among men who have sex with men ranges between 6%–40%, at least 10-fold higher than the rest of the population; the prevalence of methamphetamine use is even higher among men who have sex with men with HIV infection or a history of substance abuse (6) .

When administering interferon therapy to men who have sex with men and members of similarly vulnerable communities with a high prevalence of methamphetamine use, clinicians should counsel patients about methamphetamine use and routinely evaluate them for pretreatment antidepressant therapy.