from www.upi.com – WASHINGTON (UPI) — The U.S. Food and Drug Administration has issued warnings about drinks sold as supplements for sexual enhancement that could dangerously lower blood pressure.

The FDA says tests indicate the products, Rock Hard Extreme and Passion Coffee, contain an active ingredient that could interact with medications that include nitrates, lowering blood pressure to “dangerous levels,” the Los Angeles Times reported Thursday.

The products, sold on Web sites and possibly in retail outlets, contain sulfaildenafil, an active pharmaceutical ingredient similar to sildenafil, the active ingredient in Viagra, the FDA said.

Sulfaildenafil could interact with prescription medications that include nitrates — often prescribed for men with diabetes, high blood pressure or heart disease — and cause lowered blood pressure.

The warning comes two weeks after a Dec. 15 advisory the FDA sent to dietary supplement manufacturers saying it would crack down on illegal supplements.

“We want consumers to be aware that there are products masquerading as dietary supplements that pose significant dangers,” FDA Principal Deputy Commissioner Joshua Sharfstein said at the time of the letter.