WASHINGTON – Consumers should immediately stop using two products sold as herbal supplements that actually contain powerful prescription drugs, the Food and Drug Administration said Friday.

The recalled products are named PC SPES and SPES. Manufacturer BotanicLab recalled the products after testing by the California Health Department uncovered the contamination.

PC SPES, capsules containing a light brown powder marketed for “prostate health,” contains warfarin, a powerful blood thinner often sold under the brand name Coumadin, California health officials said.

Warfarin can cause serious bleeding, especially if taken together with aspirin or certain other drugs, and thus should be used under a doctor’s care with strict blood testing.

SPES, capsules containing a brown powder marketed as an immune enhancer, contain alprazolam, an anti-anxiety drug often sold under the brand name Xanax, the California testing found.

Alprazolam exacerbates the effects of alcohol and other sedating drugs and may be habit-forming.

The capsules were sold by mail, phone and Internet order as well as by stores and health care professionals.

Consumers with unused capsules may return them to BotanicLab, which can be reached at 1-800-458-5854. Consumers with questions also may contact California health investigators at 1-800-495-3232.

Brea, Calif.-based BotanicLab said the alprazolam may have come from contamination of raw ingredients in China and that it was strengthening its product testing.

The company said it still is analyzing the warfarin issue.