A new study has revealed a significant association between the commonly prescribed painkiller diclofenac and an increased risk of heart attack and stroke. The research indicates that even low doses of diclofenac can elevate the risk of major cardiovascular events by as much as 50%, raising concerns among healthcare professionals and prompting calls for stricter regulations.
Cardiovascular Risks of Diclofenac
The study, the largest of its kind, analyzed data from over six million individuals and found that diclofenac users faced a higher likelihood of experiencing heart failure and irregular heartbeat across all ages and genders. These findings underscore the potential dangers of diclofenac compared to other common pain relievers like paracetamol and traditional non-steroidal anti-inflammatory drugs (NSAIDs).
Cardiologist Dr. Morten Schmidt from Aarhus University Hospital in Denmark, a lead author of the study, emphasized the cardiovascular risks associated with diclofenac. In his BMJ article, Dr. Schmidt advocates for prescription-only access to diclofenac, as is the current regulation in the UK, and stresses the importance of clear warnings on product packaging.
Study Details and Findings
The observational study utilized national registry data from over 6.3 million middle-aged adults in Denmark, spanning two decades (1996-2016). Researchers associated the initiation of diclofenac treatment with increased risks of arrhythmia, stroke, heart failure, and heart attacks. The data also indicated a higher chance of cardiac death and severe internal bleeding within the upper intestines among diclofenac users.
Compared to individuals not taking any medication, diclofenac users experienced a 50% increase in health complications within just 30 days. When compared to ibuprofen or paracetamol users, there was a 20% increase, and a 30% increase compared to those on naproxen.
Regulatory Context and Expert Opinions
In the UK, diclofenac was reclassified as prescription-only in January 2015 due to concerns about serious side effects. The Medicines and Healthcare products Regulatory Agency (MHRA) cited a "small but increased" risk of heart issues as the reason for the change.
Dr. Schmidt stated, "It is time to acknowledge the potential health risk of diclofenac and to reduce its use." He also noted, "Treatment of pain and inflammation with NSAIDs may be worthwhile for some patients to improve quality of life despite potential side effects. Considering its cardiovascular and gastrointestinal risks, however, there is little justification to initiate diclofenac treatment before other traditional NSAIDs."
MHRA Guidance and Previous Research
The MHRA advises against the use of diclofenac by individuals with serious heart conditions and recommends that those with heart failure, heart disease, or stroke, as well as smokers and individuals with high blood pressure, elevated cholesterol levels, or diabetes, seek medical advice before using the medication. The MHRA maintains that diclofenac remains a safe and effective form of pain relief for most patients, except for those in specific "at risk" groups.
A 2013 Oxford University study revealed that, among 1,000 people with a moderate risk of heart disease taking 150mg of diclofenac daily for a year, approximately three could experience an avoidable heart attack, with one case being fatal.
European health officials have advised that individuals with heart conditions or a history of heart attacks or strokes should avoid diclofenac. The drug is commonly prescribed for short-term relief from dental pain and menstrual cramps by inhibiting cyclo-oxygenase, a body chemical that generates substances in response to injury, leading to pain, swelling, and inflammation.
