US drug giant Pfizer has filed a Citizen Petition with the US Food and Drug Administration (FDA) drawing attention to alleged mislabelling of generic azithromycin products sold by Israel’s Teva Pharmaceutical Industries and Germany-based Sandoz, the generics arm of Swiss drugmaker Novartis.

According to Pfizer, labels on the copycat versions of its $1.8 billion antibiotic Zithromax (azithromycin sesquihydrate) do not accurately detail the active ingredients, as they claim the drugs contain large amounts of azithromycin monohydrate instead of azithromycin sesquihydrate. Consequently, Pfizer has asked the FDA to recall these generic drugs so that the inaccuracies can be corrected.

“Patients and physicians must be able to trust that the medicine in the bottle is the same as that which is described in the label,” commented Hank McKinnell, Pfizer’s Chairman and Chief Executive Officer. And explaining the group’s actions, he said: “Pfizer want to ensure that patients do not receive generic products that fail to meet FDA standards.”

Meantime, the world’s number one drugmaker also announced that it is taking Teva and Sandoz to court over infringement of a recently-issued patent it was awarded for azithromycin sesquihydrate. Pfizer is requesting that preliminary and permanent injunctions are imposed on companies copycat formulations, which first hit the shelves in November last year.