Updated

Federal regulators approved the first antidepressant skin patch on Tuesday, providing a different way to administer a drug already used by Parkinson's disease patients.

The Food and Drug Administration approved the selegiline transdermal patch, agency spokeswoman Susan Cruzan said. The drug belongs to a class of medicines that is rarely a first or even second choice to treat depression.

It will be marketed as Emsam, said Somerset Pharmaceuticals Inc., which developed the drug, and Bristol-Myers Squib Co., which will market it.

The FDA will require the drug to bear a so-called "black-box" warning of the risks of suicidal thoughts and behaviors in children and adolescents treated with antidepressants. The drug is meant for use only by adults.

The drug's label also will carry a long list of foods, drinks and other drugs that patients must avoid while using the Emsam patch. The warnings are typical of the class of drugs to which it belongs.

Selegiline, approved in pill form by the FDA in 1989 to help treat Parkinson's disease, is a monoamine oxidase inhibitor, or MAOI. Typically, doctors prescribe MAOIs only if patients don't respond to other antidepressants, including selective serotonin reuptake inhibitors like Prozac, Zoloft and Paxil.

Although health officials say MAOIs are safe when used correctly, the drugs can cause dangerous interactions, including sudden and severe rises in blood pressure that can lead to a stroke, when patients consume food or drinks that contain a substance called tyramine — found in draft beer, red wine, fava beans, salamis, aged cheeses, soy sauce and other products.

Bristol-Myers and Somerset said Emsam patients, when using the six-milligram or lowest strength patch, shouldn't have to watch their diets. However, those using the larger nine- or 12-milligram versions of the once-a-day patch must do so.

Somerset Pharmaceuticals is a joint venture between Watson Pharmaceuticals Inc. and Mylan Laboratories Inc.