THERAPEUTICS

Brands

• Indocin, Indocin IV, Indocid, Indochron E-R, Indocin-SR, Tivorbex, Indo-Lemmon

Generic?

• Yes

Class

• Non-steroidal anti-inflammatory drug (NSAID)

Commonly Prescribed for

(FDA approved in bold)

• Relief of mild to moderate acute pain of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, gout, trauma, fractures, bursitis, tendinitis, renal colic, surgery

• Migraine, tension-type, and cluster headache

• Indomethacin-responsive headache disorders

• Suppression of uterine activity to prevent premature labor

• Patent ductus arteriosus

How the Drug Works

• Like other NSAIDs, inhibits cyclo-oxygenase (predominantly COX-1) thus inhibiting synthesis of proinflammatory thromboxane (TXA2) and prostaglandins (PGE2)

• The reason indomethacin is more effective than other NSAIDs for many headache disorders is unclear, but could be due to its structural similarities to serotonin, central vasoconstrictive and analgesic properties, or lowering of intracranial pressure. It also inhibits the metabolism of an active progesterone metabolite

How Long Until It Works

• Acute migraine: less than 2 hours

• Indomethacin-responsive headache disorders: (preventive) less than a week after starting a given daily dose

• Pain: within 30 minutes

If It Works

• Continue to use

If It Doesn't Work

• Migraine: add triptan, dihydroergotamine, antiemetic, or another NSAID

• Indomethacin-responsive headache disorders: reconsider the diagnosis

Best Augmenting Combos for Partial Response or Treatment-Resistance

• Migraine: combine with triptan or antiemetic

Tests

• None required

ADVERSE EFFECTS (AEs)

How the Drug Causes AEs

• COX-1 is required for maintaining production of prostanoids, including prostacyclin (PGI2), for GI mucosal protection and platelet aggregation inhibition

Notable AEs

• Dyspepsia, dizziness, nausea, diarrhea most common

• Inhibition of platelet aggregation is usually mild

• Elevation in hepatic transaminases (usually borderline)

Life-Threatening or Dangerous AEs

• GI ulcers and bleeding, increasing with duration of therapy

• May worsen depression, psychiatric disturbances, and parkinsonism

• May increase risk of fluid retention and edema, cardiovascular events, including myocardial infarction and stroke

• Renal insufficiency, proteinuria, and hyperkalemia

• Aseptic meningitis (rare)

• Hypersensitivity reactions: most common in patients with asthma

Weight Gain

• Unusual