Norepinephrine-enhancing antidepressant exposure associated with reduced antiviral effect of interferon alpha on...

Major depressive disorder is a common consequence of exposure to the pro-inflammatory cytokine interferon alpha, which is treated effectively with antidepressant medication. Antidepressant mode of action may conflict with interferon alpha's mechanism in treating hepatitis C however.

The purpose of this study is to prospectively explore, in a large naturalistic cohort, whether antidepressant exposure influenced end of treatment response of hepatitis C to interferon alpha.

Two hundred thirty-nine patients infected with chronic hepatitis C and due to receive treatment were recruited. All participants initiated peg-interferon-2-alpha 180 μg weekly sub-cutaneously plus oral ribavirin 800-1200 mg daily. Participants were assessed for DSM-IV major depression at baseline and four weekly during treatment.

32.6 % of the cohort was exposed to an antidepressant (serotonin-reuptake inhibitor: other categorised antidepressants 49:29). At baseline, 3.8 % had major depression and 55.2 % developed major depression during interferon alpha treatment. Exposure to an antidepressant not classified as a serotonin-reuptake inhibitor, of which all were norepinephrine-enhancing (OR 0.15, 95 % CI 0.04-0.60) and having a past history of psychiatric disorder (OR 4.41, 95 % CI 1.39-13.96) independently reduced the likelihood of end of treatment response. Serotonin-reuptake inhibitor exposure did not influence end of treatment response (OR 1.21, 95 % CI 0.35-4.19), neither did major depression at baseline (OR 2.31, 95 % CI 0.55-9.60) or during treatment (OR 0.69, 95 % CI 0.36-1.33).

Our findings support a lack of conflict of therapeutic mechanism of serotonin-reuptake inhibitor antidepressants with interferon alpha in treating hepatitis C, which may include inflammatory influence. This appears not to be true for norepinephrine-enhancing antidepressant types and warrants investigation using more direct methods.