Common Medicines May Increase Blood Clot Risk

Venous thromboembolism risk was higher in NSAID users

(RxWiki News) When dealing with a headache or other pain, many people reach for over-the-counter pain relievers like naproxen or ibuprofen. But these types of medication, known as non-steroidal anti-inflammatory drugs (NSAIDS), could come with an increased risk of blood clots.

The tie between NSAIDs and blood clots that break loose, called venous thromboembolisms (VTEs), was largely unexplored.

That prompted Patompong Ungprasert, MD, of Bassett Medical Center in Cooperstown, NY, and colleagues to review six studies of a total of 21,401 VTE events for links to NSAID use.

These researchers found that people who used NSAIDs had a higher risk of VTEs than those who did not use NSAIDs.

VTEs can block blood flow in the blood vessels, which can cause tissue damage or death.

"NSAIDs have been previously linked to a relatively higher risk of thrombosis (clotting), with several possible causes identified," said E. Lee Carter, RPh, Clinical Pharmacy Specialist at the Department of Veterans Affairs in Prestonsbrug, Kentucky. "One of the most likely is that both selective and nonselective NSAIDs reduce prostacyclin formation in the blood vessels; they accomplish this by tipping the balance of prostacyclin/thromboxane in favor of thromboxane, a prothrombotic compound."

According to Carter, "Some authors have suggested the addition of an anti-platelet medication such as aspirin to combat this possible side-effect of the NSAID, while other studies have linked a higher incidence of thrombotic events with the selective cox-2 inhibitors (Celebrex) as compared to non-selective NSAIDs such as naproxen (Naprosyn, Aleve)."

NSAIDs are a class of medicines that includes aspirin (brand name Bayer), ibuprofen (brand names Advil and Motrin) and naproxen (brand names Aleve).

In their recent study, Dr. Ungprasert and team found that NSAID users faced a 1.8 times higher risk of VTEs than patients who did not use NSAIDs.

“With the widespread use of these medicines, this increased risk may have important public health implications,” the authors wrote.

Dr. Ungprasert and colleagues wrote that the exact reasons NSAID users had a higher risk of VTEs was unclear.

These authors noted some limitations to their review, such as the fact that all types of NSAIDs were studied as one group, rather than separately.

“Our results show a statistically significant increased VTE risk among NSAIDs users,” Dr. Ungprasert said in a press statement. “Physicians should be aware of this association and NSAIDs should be prescribed with caution, especially in patients already at a higher risk of VTE.”

Immobilization, surgery, pregnancy, obesity and cancer all can raise the risk for VTE.

The review was published online Sept. 24 in Rheumatology.

No outside sources funded the research. The authors did not disclose any conflicts of interest.

Review Date: 
September 24, 2014