Diclofenac, a commonly used painkiller, has been found to potentially be linked to increased risk of cardiovascular problems by a large Danish study.
Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) that is used to treat arthritis and other joint conditions. It is available over the counter, without a prescription in many countries.
Researchers involved in this study found that the rate of first-time cardiovascular events, including heart attacks, development of atrial fibrillation, an irregular heart rhythm, or even death from heart problems, was 20 to 30 percent higher in those taking diclofenac than those using ibuprofen, naproxen, which are both also NSAIDs, or paracetamol (acetaminophen). The rate was 50 percent higher when compared to people who weren’t using any painkillers.
The data was collected from the Danish national patient registry. This data comprised of nearly 1.4 million diclofenac users, 3.9 million ibuprofen users, 292,000 naproxen users, 765,000 paracetamol users, and 1.3 million people who were not using any of these painkillers. This study utilized a larger participant pool than previous studies, which is a strength, providing greater evidence for the findings.
Morten Schmidt, the lead author of the study, stated it is important to note that the “absolute risk for an individual patient is low.” This means all of the results found in the study are relative; it was calculated that roughly one person per year had a cardiovascular event among every 400 study participants taking diclofenac. Accordingly, the rates are lower for those taking other painkillers and much lower for those taking no painkillers.
With these results in mind, the researchers recommend using other NSAIDs before diclofenac. They concluded that diclofenac should not be available over the counter due to their findings of increased risk of cardiovascular events. They state even when it is prescribed, it should be accompanied by warnings about potential risks and side effects. This increased risk was seen even within 30 days of first using the drug and even when using low dosages. The researchers also note that diclofenac was associated with an increased risk of gastrointestinal bleeding when compared with ibuprofen.
It is important to note that the study can’t prove a causal relationship between diclofenac and increased cardiovascular events, as the study was not a controlled experiment. However, this study does open up the suggestion that diclofenac may be linked somehow with an increased risk of cardiovascular events. A strength of the study is that the researchers utilized a large amount of data providing strong evidence for future clinical decision making. With this current study in mind, it may be helpful for future research to further identify a potential ingredient or chemical within diclofenac that may be causing the suggested association. It should also take into consideration other lifestyle factors that may have been hidden and unclear from the data set that may be affecting the relationship.