Indomethacin

Indomethacin belongs to the NSAID family and works by blocking the production of prostaglandins, the chemical messengers behind inflammation, swelling and pain. UK product information lists active rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, degenerative disease of the hip, acute musculoskeletal disorders, low back pain and acute gouty arthritis. It is also licensed for pain, inflammation and oedema after orthopaedic procedures and for painful periods (primary dysmenorrhoea). It eases symptoms but does not alter the underlying course of arthritis.

This product comes in three strengths: 25 mg, 50 mg and 75 mg. Whichever strength you choose, the quantity runs from 30 up to 360 (30, 60, 90, 120, 180, 270 or 360). The larger quantities are aimed at people on long-term treatment whose prescriber has already settled on a stable dose. This is an imported generic, so packaging may differ in appearance from UK packs.

The dose of this NSAID is adjusted to each person, using the lowest amount that controls symptoms for the shortest time needed. Oral doses are usually split across the day and taken with food, a meal or milk to reduce stomach upset. Starting low and increasing gradually lowers the chance of headache, which is a common early effect. Daily totals above 200 mg are not normally used. Older people are more prone to side effects and need particular care. No dose is set for children, because safe use in that age group has not been shown. If a dose is missed, take the next one at the usual time rather than doubling up, and keep Indomethacin away from other NSAIDs such as ibuprofen, naproxen or high-dose aspirin unless the prescriber has said otherwise.

In the UK the medicine carries the international name indometacin, while Indomethacin is the older spelling still widely used elsewhere. Indometacin is a prescription-only medicine (POM) and is available as generic oral preparations and as suppositories. Because NSAIDs carry stomach, heart and kidney risks, the prescriber weighs these against the expected benefit before starting or continuing treatment.

The SmPC rules out use with an active or previous peptic ulcer, or with recurrent gut lesions. It should also be avoided by anyone who has had asthma attacks, urticaria or rhinitis after aspirin or another NSAID, and by people with nasal polyps linked to angio-oedema. It is contraindicated in the third trimester of pregnancy and while breastfeeding. Known interactions include anticoagulants, probenecid (which raises indometacin levels), methotrexate, lithium (blood levels rise), diuretics and blood pressure medicines, whose effect may be weakened; combining it with potassium-sparing diuretics can push potassium up. Reduced kidney blood flow, heart failure and liver disease all call for caution.

Headache, sometimes with dizziness or light-headedness, is among the most frequent problems and usually appears early on. Others include indigestion, nausea, stomach pain, diarrhoea, drowsiness, tiredness, low mood and vertigo. Black or bloody stools, vomiting blood or severe stomach pain may mean bleeding or an ulcer and need urgent attention. Chest pain, sudden breathlessness, swelling of the face or a severe rash should be treated as an emergency at A&E. Because drowsiness and blurred vision are possible, it is sensible not to drive until you know how Indomethacin affects you.