WASHINGTON, DC—The over-the-counter (OTC) 220-mg dose of naproxen (Aleve) is as safe for the cardiovascular system as the 550-mg prescription-strength version of the drug (Naprosyn), and its antiplatelet effects are similar to those of daily low-dose aspirin, researchers reported at the American College of Rheumatology–Association of Rheumatology Health Professionals annual meeting.

“We all know that when Vioxx and Bextra were withdrawn from the market, people had serious questions about the cardiovascular effects of all NSAIDs [nonsteroidal antiinflammatory drugs], whether traditional NSAIDs like naproxen or newer COX [cyclooxygenase]-2 inhibitors like Vioxx and Bextra,” said lead investigator Michael Schiff, MD, of the University of Colorado School of Medicine, and medical director, Denver Arthritis Clinic Research Unit. “Our data address this question.”

Naproxen was studied in 41 patients who were randomized to 1 of 4 treatments for 7 days: naproxen 220 mg, twice daily; naproxen 220 mg, 3 times daily; naproxen 550 mg, twice daily; or placebo.

After the 7 days, each patient waited at least 6 days before taking aspirin (81 mg/d) for 7 days, for comparison. The standard blood and urine marker, serum thromboxane B2, was used to measure platelet inhibition.

Both 220-mg dosages achieved a  98% to 99% antiplatelet effect similar to the 550-mg dose and low-dose aspirin. Although this was not a “gold standard” large clinical trial, Dr Schiff noted that the laboratory marker used had enough power to reach meaningful conclusions.

“This study demonstrates that the effect on platelet function of even over-the-counter, low-dose naproxen is similar to that of prescription-strength naproxen and low-dose aspirin,” said Eric Matteson, MD, MPH, of the Mayo Clinic College of Medicine, Rochester, Minn.

“Aleve will not be risky to the cardiovascular system, and it seems it could even be cardioprotective,” Dr Schiff added. “And since the over-the-counter version of the drug is as cardioprotective as the prescription version, and it has a better gastrointestinal side-effect profile, this is good news.”