Venlafaxine: A Cause of Hepatitis?
Venlafaxine (Effexor generic, Wyeth), an anti-depressant sometimes indicated for women with vasomotor symptoms of menopause, may lead to drug-induced hepatitis, warn pharmacists from the University of Iowa.
A healthy 60-year-old woman developed hepatitis after taking venlafaxine 75 mg/day for one month. At her first visit, she had fever, cough, headache, and myalgia. An upper respiratory tract infection was the diagnosis. Three days later, she had persistent fever, chills, congestion, sharp abdominal pain, and marked upper-quadrant tenderness. She had nausea and no appetite, but she was not vomiting.
A sonogram revealed an enlarged liver (18.2 cm), a dilated mid-common bile duct, lymph nodes near the pancreatic head (up to 1 cm), and fluid collection between the gallbladder and liver. She had no gallstones, and the gallbladder wall was not thickened. Her blood cell counts, as well as lipase, amylase, and total bilirubin levels, were normal, but liver enzymes were greatly elevated.
The next diagnosis was sinusitis. The patient’s abdominal tenderness was presumed to be a result of exacerbation of her gastroesophageal reflux disease, virus-related hepatitis, adverse drug events, or biliary obstruction. The team thought that venlafaxine might be contributing to, but not causing, the problems.
Four weeks after the venlafaxine therapy was stopped, her liver enzyme levels returned to normal. Upon re-challenge with a venlafaxine dose of 37.5 mg/day, they became elevated again.
In other cases, venlafaxine caused dramatic liver problems, but values normalized after the drug was stopped.
