Hepatitis associated with low-dose venlafaxine for postmenopausal vasomotor symptoms

To report a case of drug-induced hepatitis associated with low-dose venlafaxine.

A 60-year-old white woman receiving venlafaxine 75 mg daily for vasomotor symptoms presented after one month of therapy with nonspecific complaints, including abdominal pain. A series of diagnostic and laboratory tests revealed an enlarged liver and elevated alanine aminotransferase (ALT) up to 372 U/L, aspartate aminotransferase (AST) up to 99 U/L, gamma-glutamyltransferase (GGT) up to 962 U/L, and alkaline phosphatase up to 758 U/L. All potential hepatotoxic medications were discontinued. Within one week after stopping venlafaxine, her liver function test results showed marked improvement. Almost 4 weeks after discontinuing therapy, venlafaxine 37.5 mg was reinitiated. Her ALT, AST, GGT, and alkaline phosphatase again increased to 269, 49, 256, and 263 U/L, respectively, 6 days after resuming therapy. Upon discontinuation of venlafaxine, her liver function abnormalities resolved.

This case is significant due to the severity of symptoms and consequent liver function test results involved in diagnosing drug-induced hepatitis. It is also remarkable because of the hepatotoxicity that occurred initially and on rechallenge with low-dose venlafaxine. The hepatotoxic effects of venlafaxine have been characterized as rare and idiosyncratic. The Naranjo probability scale revealed that the adverse drug event was probable.

Venlafaxine therapy can lead to drug-induced hepatitis, even when used at low doses. Clinicians should be aware of this possible adverse effect of venlafaxine therapy and monitor patients closely after initiation of therapy.