indometacin
indomethacin (indometacin (UK))
Pharmacologic class: Nonsteroidal anti-inflammatory drug (NSAID)
Therapeutic class: Anti-inflammatory, analgesic, antipyretic
Pregnancy risk category B (third trimester: D)
FDA Box Warning
• Drug may increase risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke (which can be fatal). Risk may increase with duration of use, and may be greater in patients who have cardiovascular disease or risk factors for it.
• Drug is contraindicated for perioperative pain in setting of coronary artery bypass graft surgery.
• Drug increases risk of serious GI adverse events, including bleeding, ulcers, and stomach or intestinal perforation, which can be fatal. These events can occur at any time during therapy and without warning. Elderly patients are at greater risk.
Action
Unknown. Thought to inhibit cyclo-oxygenase, an enzyme needed for prostaglandin synthesis.
Availability
Capsules: 25 mg, 50 mg
Capsules (sustained-release): 75 mg
Oral suspension: 25 mg/5 ml
Indications and dosages
➣ Rheumatoid arthritis; osteoarthritis; ankylosing spondylitis
Adults: 25 to 50 mg P.O. two or three times daily, not to exceed 200 mg daily; or one 75-mg sustained-release capsule P.O. once or twice daily
➣ Acute gouty arthritis
Adults: 50 mg P.O. t.i.d. until pain is tolerable; then reduce dosage rapidly and, finally, discontinue drug. Don't give sustained-release form.
➣ Acute bursitis or tendinitis of shoulder
Adults: 75 to 150 mg P.O. daily in three or four divided doses. Discontinue once inflammation is controlled.
Off-label uses
• Bartter's syndrome
• Pericarditis
Contraindications
• Hypersensitivity to drug, its components, or other NSAIDs
• Active GI bleeding
• Concurrent diflunisal use
Precautions
Use cautiously in:
• severe cardiovascular, renal, or hepatic disease
• history of ulcer disease
• elderly patients
• pregnant or breastfeeding patients
• children ages 14 and younger (efficacy not established).
Administration
• Give with food, full glass of water, or antacids to reduce GI upset.
• Don't open or crush capsules.
• For arthritis, give up to 100 mg of daily dose at bedtime as needed to reduce nighttime pain and morning stiffness.
• Don't give sustained-release form to patients with gouty arthritis.
Adverse reactions
CNS: headache, dizziness, drowsiness, fatigue, vertigo, depression, seizures
EENT: tinnitus
GI: nausea, vomiting, diarrhea, constipation, abdominal pain or cramps, dyspepsia, ulcers, GI bleeding
Other: allergic reactions including anaphylaxis
Interactions
Drug-drug. Antihypertensives, diuretics: decreased efficacy of these drugs
Corticosteroids, other NSAIDs: additive adverse GI reactions
Cyclosporine: increased risk of nephrotoxicity
Diflunisal: potentially fatal GI hemorrhage
Lithium, methotrexate, zidovudine: increased risk of toxicity from these drugs
Probenecid: increased risk of indomethacin toxicity
Drug-diagnostic tests. Dexamethasone suppression test: false-negative result
Drug-herbs. Anise, arnica, chamomile, clove, dong quai, feverfew, garlic, ginger, ginkgo, ginseng: increased bleeding risk
Patient monitoring
• Assess for dizziness, drowsiness, headache, fatigue, and exacerbation of depression, epilepsy, or parkinsonism.
• Monitor for drug efficacy, indicated by improved joint mobility, pain relief, and decreased inflammation.
• Monitor urine output for marked reduction.
• Watch for signs and symptoms of GI bleeding and ulcers.
Patient teaching
• Tell patient to take with food, full glass of water, or antacid to reduce GI upset.
• Advise patient not to open or crush capsules.
• Inform breastfeeding patient that indomethacin enters breast milk and may cause seizures in infant. Advise her to use a different infant feeding method during therapy.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, balance, and alertness.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and herbs mentioned above.