Last Updated: 2003-06-04 12:39:34 -0400 (Reuters Health)

NEW YORK (Reuters) - Pfizer Inc. said on Tuesday it was suing two companies connected to counterfeit versions of its cholesterol drug Lipitor, the world's top-selling prescription medicine.

Pfizer said the fake Lipitor was found in packages prepared by Med-Pro Inc., a pharmaceutical repackaging company based in Nebraska, and distributed by Kansas City-based Albers Medical Distributors.

The world's largest drugmaker said it had warned pharmacists and other health care professionals about the counterfeit Lipitor, which was believed to be in limited distribution.

Pfizer said it has no relationship with either Med-Pro or Albers, which last month issued a recall for certain Med-Pro packages because they may contain counterfeit Lipitor.

The U.S. Food and Drug Administration (FDA) on May 23 warned consumers about the possibility of fake Lipitor in circulation.

The FDA on Tuesday said its continuing investigation had turned up additional counterfeit supplies of Lipitor, in bottles affixed with labels indicating the tablets had been repackaged by Med-Pro.

Calls to Med-Pro were referred to its attorney, who was not immediately available to comment.

Pfizer said it began the legal proceeding to identify the source of the fake Lipitor and halt its distribution.

Pfizer, which has also had to deal with phony versions of its anti-impotence drug Viagra, said it became aware of the counterfeit Lipitor when patients and pharmacists complained about an unusually bitter taste.