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Indomethacin: 7 things you should know

Medically reviewed by Carmen Fookes, BPharm. Last updated on Aug 17, 2022.

1. How it works

  • Indomethacin may be taken to relieve pain and inflammation.
  • Indomethacin works by blocking the effects of the enzymes cyclooxygenase (COX)-1 and COX-2. This prevents prostaglandin synthesis (prostaglandins elevate body temperature and make nerve endings more sensitive to pain transmission).
  • Indomethacin belongs to a group of medicines known as NSAIDs (nonsteroidal anti-inflammatory drugs).

2. Upsides

  • Effective for the relief of pain and inflammation associated with osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, acute painful shoulder (bursitis or tendonitis), and acute gouty arthritis.
  • NSAIDs (including indomethacin) are considered first-line options for mild-to-moderate acute pain because at correct dosages they are effective, do not cause dependence, and are readily available at a low cost.
  • Available as immediate-release capsules, suspension, extended-release capsules, and suppository form.
  • Relieves inflammation and pain.
  • Temporarily relieves fever.
  • Does not cause dependence and is readily available at a low cost.
  • Generic indomethacin is available.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Indigestion, heartburn, and very occasionally, stomach ulceration and bleeding. People of an older age, taking other medicines that affect the stomach, or who drink more than 3 glasses of alcohol per day may be more at risk. Indomethacin is considered to carry a high risk for stomach-related side effects compared with other NSAIDs.
  • A headache is also a common side effect. Other side effects include tinnitus (continuous ringing or buzzing in the ears), constipation, and difficulty concentrating.
  • Indomethacin is one of the most potent NSAIDs and is generally only used after other NSAIDs have proved ineffective.
  • NSAIDs (including indomethacin) have been associated with an increased risk of stroke or heart attack. The risk may be higher in patients with pre-existing cardiovascular conditions and with higher dosages. Indomethacin is considered to carry a high risk for cardiovascular-related side effects compared with other NSAIDs.
  • Prescription-only. Oral and rectal preparations are not available over-the-counter (have to be prescribed).
  • May not be suitable for some people including those with kidney disease, a history of stomach ulcers or other gastrointestinal disorders, with pre-existing cardiovascular disease, or following coronary artery bypass graft surgery. Should not be used by children aged less than 14 years and during pregnancy.
  • May interact with some other medicines such as warfarin, SSRIs, ACE inhibitors, and diuretics.
  • NSAIDs, such as indomethacin, should not be used during the last three months of pregnancy because they can cause premature closure of the fetal ductus arteriosus. In addition, the use of NSAIDs at around 20 weeks gestation or later in pregnancy may cause fetal kidney problems leading to oligohydramnios (low amniotic fluid volume) and in some cases kidney impairment. If NSAID treatment is deemed necessary between 20 and 30 weeks of pregnancy, use the lowest effective dose for the shortest possible time. Avoid NSAIDs after 30 weeks gestation.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

  • Indomethacin relieves inflammation and pain associated with various types of arthritis. The risk of stomach-related and cardiovascular side effects may be higher with indomethacin than that seen with other NSAIDs such as ibuprofen.

5. Tips

  • Take with food to reduce stomach-related adverse effects.
  • Always use the lowest effective dose for the shortest duration consistent with the condition being treated.
  • Response to different NSAIDs can vary so switching types (for example, from indomethacin to naproxen) may improve response.
  • Talk to your doctor if you experience any abdominal pain after taking indomethacin, particularly if the pain persists.
  • NSAIDs such as indomethacin should not be used in the last 3 months of pregnancy; ask your doctor before using any medication during pregnancy.
  • Do not take NSAIDs such as indomethacin or aspirin if you have experienced asthma or hives due to NSAID use in the past.
  • If you are taking indomethacin and find it is not working very well for you, you may like to try a different NSAID.
  • Do not use this medicine immediately following heart bypass surgery (coronary artery bypass graft, or CABG).
  • See a doctor immediately if you experience any difficulty with breathing, unexplained sickness or fatigue, loss of appetite, vision changes, fluid retention, or abnormal bleeding.
  • NSAIDs, such as indomethacin, should not be used in the last 3 months of pregnancy; always ask your doctor before using any medication during pregnancy. Do not use NSAIDs such as indomethacin between 20 and 30 weeks gestation without your doctor's advice because this may cause kidney problems and low amniotic fluid volumes in the newborn. Acetaminophen may be considered to treat pain and inflammation during pregnancy.

6. Response and effectiveness

  • Peak levels are reached 2 hours after administration, and 90% of a dose is absorbed within 4 hours of administration.
  • Indomethacin is approximately 10 times as potent as aspirin.

7. Interactions

Medicines that interact with indomethacin may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with indomethacin. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with indomethacin include:

  • ACE inhibitors or ARBs, such as captopril, enalapril, or losartan
  • antibiotics, such as ciprofloxacin or vancomycin
  • anticoagulants (blood thinners) such as apixaban, dabigatran, fondaparinux, heparin, or warfarin
  • antidepressants, such as citalopram, escitalopram, fluoxetine, or paroxetine
  • antifungals, such as voriconazole
  • antiplatelets, such as clopidogrel or ticagrelor
  • beta-blockers, such as acebutolol, atenolol, bisoprolol, or carvedilol
  • bisphosphonates, such as alendronate
  • corticosteroids, such as dexamethasone or prednisone
  • digoxin
  • diuretics (water pills), such as chlorthalidone, chlorothiazide, hydrochlorothiazide (HCTZ), or furosemide
  • glucagon
  • haloperidol
  • HIV medications (eg, Stribild, tenofovir)
  • metformin
  • other nonsteroidal anti-inflammatories (NSAIDs), such as celecoxib, diclofenac, etodolac, ibuprofen, ketorolac, meloxicam, nabumetone, or naproxen
  • sulfonylureas (a type of diabetes medication), such as glimepiride, glyburide, or glipizide
  • supplements, such as glucosamine, omega-3 fatty acids, vitamin E
  • others, such as cyclosporine, lithium, methotrexate, pemetrexed, pirfenidone, or tacrolimus.

Drinking alcohol while taking indomethacin may increase the risk of gastrointestinal-related side effects or kidney damage.

Note that this list is not all-inclusive and includes only common medications that may interact with indomethacin. You should refer to the prescribing information for indomethacin for a complete list of interactions.


Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use indomethacin only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2023 Revision date: August 17, 2022.