When it comes to medications, one of the biggest mistakes we make is to divide pharmaceuticals into two sections in our minds. In one section, you find over-the-counter, no limits, “safe” medication, while the other section consists of behind-the-counter drugs that require a prescription; those we consider “dangerous.” Because we don’t need a prescription to get a certain type of chemical drug, we easily conclude that it is safe. However, the reality is far different.

Danish researchers discovered in a new study that non-steroidal anti-inflammatory drugs (NSAIDS) which are used to manage pain may increase the risk of getting a cardiac arrest.

NSAID pain relievers are used worldwide. They are the most common type of over-the-counter medication. NSAID use has been linked to platelet aggregation, raising blood pressure, causing arteries to constrict, causing blood clots, and increasing fluid retention.

“Allowing these drugs to be purchased without a prescription, and without any advice or restrictions, sends a message to the public that they must be safe,”Gunnar H. Gislason, a professor of cardiology at Copenhagen University Hospital Gentofte in Denmark, said in a press release. “Previous studies have shown that NSAIDs are related to increased cardiovascular risk which is a concern because they are widely used.”

The researchers reviewed the medical records of 28,947 patients who experienced an out-of-hospital cardiac arrest between the year 2001 and 2010 and were part of the Danish Cardiac Arrest Registry. They focused on the use of prescriptions NSAID pain relievers in 3,376 patients with cardiac arrest, which included ibuprofen, diclofenac, and naproxen as well as the COX-2 selective inhibitors celecoxib and rofecoxib. Because ibuprofen is the only approved over-the-counter NSAID in Denmark, the use of over-the-counter medications was not evaluated.

The researchers compared NSAIDs use during the 30 days before the cardiac arrest to the use of NSAIDs during a separate 30-day period without any cardiac arrest.

The results showed that NSAIDs use was linked to a 31% increase in the risk of cardiac arrest. Ibuprofen showed an increased risk of 31 percent while diclofenac increased the risk of cardiac arrest by 50%.   Naproxen, rofecoxib, and celecoxib were not associated with an increase in the risk of cardiac arrest.

“The findings are a stark reminder that NSAIDs are not harmless,” Gislason said. “Diclofenac and ibuprofen, both commonly used drugs, were associated with significantly increased risk of cardiac arrest. NSAIDs should be used with caution and for a valid indication. They should probably be avoided in patients with cardiovascular disease or many cardiovascular risk factors.”

Gislason urged patients to be cautious when employing over-the-counter NSAID pain relievers.

“Over-the-counter NSAIDs should only be available at pharmacies, in limited quantities, and in low doses,” Gislason said. “Do not take more than 1,200 mg of ibuprofen per day. Naproxen is probably the safest NSAID and we can take up to 500 mg a day. Diclofenac is the riskiest NSAID and should be avoided by patients with cardiovascular disease and the general population. Safer drugs are available that have similar painkilling effects so there is no reason to use diclofenac.”