Over the past two years, there has been documented concern about the cardiovascular safety of some pain relievers and arthritis treatments.
Manufacturers of naproxen had previously been asked to add warnings about the heart risk of the drug after the new COX-2 inhibitors were found to greatly increase the possibility of having heart attacks and strokes.
The COX-2 inhibitors were developed to be safer alternatives to naproxen and other NSAIDs, which can cause sometimes fatal stomach bleeding.
This study aimed to determine the antiplatelet effect of the naproxen. Accumulating platelets can cause clotting in the arteries, which can lead to a heart attack. Previous research has found the prescription strength dose of naproxen to have positive antiplatelet effects, but this study represents the first time that data have been collected at the over-the-counter (OTC) dose.
Measuring the inhibition of serum thromboxane B2 (TXB2), researchers determined that OTC doses of naproxen sodium produced an antiplatelet effect similar to prescription strength naproxen. Researchers did not examine any clinical endpoint, so the clinical significance of these data is undetermined.
“These data, confirming that the OTC dose of naproxen sodium has a measurable antiplatelet effect, add to the body of evidence about the safety of this compound,” said study author Marc Hochberg, professor of medicine, University of Maryland School of Medicine.
Naproxen has been used for more than 30 years in the US as a prescription product and was introduced as an OTC product in June 1994.