Ketoprofen

Is ketoprofen safe?

It depends on the form. Ketoprofen gel is a reasonable choice for a painful knee or a sprain if you can keep the skin out of the sun. Ketoprofen capsules work well for arthritis and period pain but are harder on the stomach than ibuprofen, celecoxib or even diclofenac.

The score of 69 is for capsules taken by mouth, the form approved in the US, so that it can be compared with the other NSAID tablets. That puts it level with diclofenac, a little below ibuprofen (74) and naproxen (73). The gel, the main form sold in the UK and much of Europe, puts only about 5% of the drug into the blood and avoids most of those risks, but it brings one of its own: sun allergy.

The gel and sunlight

Ketoprofen can make skin react to ultraviolet light. With the gel this shows up as photoallergy: a red, itchy, sometimes blistering rash where the gel was applied, after exposure to sun. The French regulator received reports even after dim sunlight, and reactions in people who also used cosmetics containing the sunscreen octocrylene, even without sun. In December 2009 France suspended all topical ketoprofen.

The European Medicines Agency reviewed the gels in 2010. It found that reports were rare across the EU and kept them on the market, but said they should be prescription-onlyPrescription-only medicineA medicine that can be supplied only with a prescription from a doctor or another authorised prescriber.More in the glossary and carry stronger sun warnings. The UK gel label now sets these rules:

• Keep treated skin covered from sun, including hazy sun and sunbeds, during treatment and for 2 weeks after.
• Wash your hands after every application.
• Do not use it on broken skin, eczema or acne, under a tight bandage, or if you have ever had a photosensitivity reaction.
• Do not use it if you are allergic to fenofibrate, tiaprofenic acid, sunscreens or perfumes.
• Stop at once if any rash appears.

Does the gel work?

Better than most topical NSAIDs, on the evidence. A 2016 Cochrane review of knee osteoarthritis found ketoprofen gel gave clinical success to 1 extra person in about 7 over 6 to 12 weeks, compared with a dummy gel (four trials, 2,573 people). Topical diclofenac managed about 1 in 10. Ketoprofen did not raise local skin side effects in those trials. For sprains and strains, a 2015 Cochrane review put ketoprofen gel among the most effective, helping 1 extra person in 2.5, though from five studies in the 1980s.

The UK label allows 2 to 4 g, two to four times a day, for up to 7 days, with a maximum of 15 g a day. Large amounts on the skin can still cause effects in the body, including asthma attacks and kidney problems.

Ketoprofen capsules and the stomach

Taken by mouth, ketoprofen is a fast, short-acting NSAID, with a half-life of about 2 hours. Its weak point is the gut. In 2007 the MHRA reminded doctors that studies had raised concern about its stomach safety, that the recommended maximum is 100 to 200 mg a day, and that it is ruled out for anyone with any past stomach bleed, ulcer or perforation.

There is much less data on the heart. Ketoprofen was not among the drugs in a 2011 review of population studies of NSAID heart risk, so its heart risk is best assumed to be that of the class: the US capsule label carries the same boxed warningBoxed warningThe strongest safety warning the US FDA puts on a medicine's label, printed inside a black border at the top.More in the glossary for heart attack and stroke as every prescription NSAID.

Who should be careful

Talk to your doctor or pharmacist before using ketoprofen capsules if you have had a stomach ulcer or bleed, heart disease, a stroke or high blood pressure, kidney or liver disease, or asthma that reacts to aspirin, or if you take a blood thinner, an SSRI, lithium, methotrexate or probenecid. The US label says people over 75 should start on a lower dose.

Do not combine ketoprofen with other NSAIDs, and do not use the gel on top of NSAID tablets without advice. A large overdose of capsules can cause drowsiness, breathing problems or seizures: call Poison Control on 1-800-222-1222 in the US or NHS 111 in the UK. A lower score is no reason to stop a medicine your doctor prescribed.

How we scored it

The score covers capsules taken by mouth; the gel is a lower-risk way to use the same drug if you avoid the sun. Dependence (97), track record (90) and overdose marginOverdose marginHow far a normal dose is from a harmful one. A wide margin means an accidental extra dose is unlikely to cause serious harm.More in the glossary (82) are strong. Serious side effects (57) sit below ibuprofen and naproxen because of the higher stomach risk in real-world studies and thin heart data. Regulatory warnings (35) reflect the boxed warningBoxed warningThe strongest safety warning the US FDA puts on a medicine's label, printed inside a black border at the top.More in the glossary, the 2007 MHRA stomach warning and the EU's 2010 action on the gels.