The everyday painkiller Britain moved behind the pharmacy counter
Diclofenac, familiar as Voltaren gel and tablets, eases arthritis, migraines, kidney stones and sprains, and Americans filled more than 9 million prescriptions for it in 2023. Yet a large 2013 analysis found it raised serious cardiovascular events by about a third, and in 2015 UK regulators made it prescription-only.
Diclofenac belongs to the nonsteroidal anti-inflammatory family and, like its relatives, is thought to act by cutting the body's production of prostaglandins, chemical signals involved in pain and inflammation. It comes in more forms than most drugs: tablets, suppositories, injections into muscle or vein, skin gels and eye drops. A dose relieves pain for up to eight hours. Chemically it is sold as the acid or as a sodium or potassium salt.
The list of uses is long. It treats gout and arthritis pain, period cramps, rheumatic disease, kidney stones and gallstones, acute migraine and pain after surgery or injury, especially when swelling is involved. Topically it helps with minor sprains and bruises and with actinic keratosis. Eye drops calm inflammation after cataract removal and ease pain after corneal laser surgery, and it is often used for chronic cancer pain with an inflammatory component.
Side effects range from stomach pain, nausea, dizziness and swelling to bleeding in the gut, ulcers, kidney trouble, heart disease and stroke. A combination pill adds misoprostol to protect the stomach, although drugs such as omeprazole are usually preferred because they work at least as well and are better tolerated. It is avoided in late pregnancy, in people with active ulcers or gut bleeding, and around coronary bypass surgery; breastfeeding is considered likely safe.
Scrutiny intensified after rofecoxib was linked to heart attacks in 2004. A meta-analysis of studies up to April 2006 put diclofenac users' relative rate of heart disease at 1.63 times that of non-users. The 2013 study estimated that for every 1000 people taking it for a year, three extra would suffer a major vascular event, one of them fatal. Peter Weissberg of the British Heart Foundation stressed that the absolute risk is small and that people in chronic pain may judge it worth taking. In 2020 the FDA added warnings for all NSAIDs about foetal kidney problems.
Source: Diclofenac
