Piperazine hepatitis.

The first reported case of piperazine toxicity resembling viral hepatitis is described in a 25-year-old woman. The illness, which was severe, occurred after administration of the drug on two separate occasions. The evidence favors a hypersensitivity mechanism rather than a direct toxic effect of piperazine or its metabolites on the liver. The humoral or cellular immune basis for such hypersensitivity has not been elucidated.