FDA warns of skin reactions with alcoholism drug

The Food and Drug Administration said physicians and patients should watch for swelling, infection and other skin complications at the point where the drug is injected. The agency stressed that doctors must use the proper needle to administer Vivitrol, and inject it directly into the patient's muscle, not into fatty tissue.

Nearly 200 reports of skin problems have been reported to the agency from patients taking the drug. Sixteen patients required surgery, ranging from draining puss to removing tissue, according to a notice posted to the FDA's Web site Tuesday. The FDA said patients whose skin does not improve within two weeks should see a surgeon.

Cephalon spokeswoman Candace Steele said the Frazer, Pa.-based company believes some of the problems resulted from improper injection of the drug. She added that women may be at higher risk because they often have thicker layers of fat than men.

Steele said risks of skin reactions are already mentioned in the product's label, adding that "we are committed to working with FDA to make sure physicians understand this information."

The FDA said regulators are working with company officials on a stronger, more prominent warning label.

Vivitrol was approved in 2006 as a treatment for alcohol addiction, alongside counseling or group therapy. The once-a-month injection is an alternative to an older version of the drug which came as a daily pill. It works by blocking neurotransmitters in the brain believed to be associated with alcohol dependence, which diminishes the craving for alcohol.

Cephalon has agreed to pay Alkermes up to $220 million to market Vivitrol, assuming it meets certain sales milestones. It competes against Forest Laboratories' sobriety pill Campral, as well as various generic versions of the drug.

Shares of Cambridge, Mass.-based Alkermes fell 44 cents to close at $16.45 Tuesday, while Cephalon shares added 4 cents to close at $76.92.