indomethacin

Indomethacin is a nonsteroidal anti-inflammatory drug (NSAID) that reduces fever, pain and inflammation. It is similar to ibuprofen (Motrin) and naproxen (Naprosyn, Aleve).

Indomethacin works by reducing the production of prostaglandins. Prostaglandins are chemicals that the body produces and which cause the fever and pain that are associated with inflammation. Indomethacin blocks the enzymes that make prostaglandins (cyclooxygenase 1 and 2) and thereby reduces the levels of prostaglandins. As a result, fever, pain and inflammation are reduced. Indomethacin is available in an extended release form.

The FDA first approved indomethacin in January 1965.

Common side effects of indomethacin are:

• nausea,
• vomiting,
• diarrhea,
• stomach discomfort,
• heartburn,
• rash,
• headache,
• dizziness and
• drowsiness.

Other important side effects are:

• Fluid retention,
• blood clots,
• heart attacks,
• hypertension (high blood pressure), and
• heart failure.

Some individuals are allergic to NSAIDs and may develop shortness of breath when an NSAID is taken. People with asthma are at a higher risk for experiencing serious allergic reaction to NSAIDs. Individuals with a serious allergy to one NSAID are likely to experience a similar reaction to a different NSAID.

Indomethacin may cause ulceration of the stomach or intestine, and the ulcers may bleed. Sometimes, ulceration may lead to perforation of the intestine and bleeding can occur without abdominal pain, and black tarry stools, weakness, and dizziness upon standing (orthostatic hypotension) may be the only signs of a ulceration.

NSAIDs can reduce the ability of blood to clot thereby increasing bleeding after an injury.

NSAIDs reduce the flow of blood to the kidneys and impair function of the kidneys. The impairment is most likely to occur in patients with preexisting impairment of kidney function or congestive heart failure, and use of NSAIDs in these patients should be done cautiously. Individuals who have nasal polyps or are allergic to aspirin or other NSAIDs should not use indomethacin because there is an increased risk of severe allergic reactions in these individuals.

• The recommended adult dose of regular release indomethacin for treating inflammation or rheumatoid disorders is 50-200 mg per day split into 2-3 doses.
• The dose for extended release indomethacin is 75-150 mg divided into two daily doses.
• Bursitis or tendonitis are treated with a total dose of 75-150 mg daily of regular release indomethacin divided into 3 or 4 doses or 75-150 mg daily of extended release divided into two doses.
• Acute gouty arthritis is treated with 50 mg every 8 hours for 3 to 5 days. I
• Indomethacin should be taken with food and 8-12 ounces of water in order to reduce abdominal discomfort.

Cholestyramine (Questran) and colestipol (Colestid) may decrease the absorption of indomethacin by binding to indomethacin in the intestine and preventing absorption into the body. Indomethacin and other NSAIDs may decrease the elimination of lithium (Eskalith, Lithobid) by the kidneys and, therefore, increase the blood level of lithium, which could lead to lithium toxicity.

Indomethacin may interfere with the blood pressure-lowering effects of drugs that are given to reduce blood pressure. This may occur because prostaglandins play a role in the regulation of blood pressure.

When indomethacin is used in combination with methotrexate (Rheumatrex, Trexall) or aminoglycosides (for example, gentamicin) the blood levels of the methotrexate or aminoglycoside may increase, presumably because their elimination from the body is reduced. This may lead to more methotrexate or aminoglycoside-related side effects.

Indomethacin should be avoided by patients with a history of asthma attacks, hives or other allergic reactions to aspirin or other NSAIDs.

If aspirin is taken with indomethacin there may be an increased risk for developing an ulcer.

Persons who have more than 3 alcoholic beverages per day may be at increased risk of developing stomach ulcers when taking indomethacin or other NSAIDs.

Indomethacin increases the negative effect of cyclosporine on kidney function and reduces the effect of furosemide (Lasix) and thiazide diuretics because of prostaglandin inhibition.

Individuals taking oral blood thinners or anticoagulants, for example, warfarin (Coumadin), should avoid indomethacin because indomethacin also thins the blood, and excessive blood thinning may lead to bleeding.

Use during pregnancy has not been adequately studied. Indomethacin may have adverse effects on the fetus.

Indomethacin is excreted in breast milk and therefore should be avoided by nursing mothers.

What preparations of indomethacin are available?

• Capsules: 25 and 50 mg
• Capsules, extended release: 75 mg
• Suspension: 25 mg/ml
• Suppositories: 50 mg.
• Injection (powder): 1 mg

How should I keep indomethacin stored?

Capsules should be kept at room temperature, 15 C to 30 C (59 F to 86 F). Oral suspension and suppositories should be kept below 30 C (86 F). The oral suspension should not be frozen.