Indomethacin

1. Mechanism
   1. NSAID in the acetic acid class (indole)
2. Pharmacokinetics
   1. Half life: 2 hours
3. Advantages
   1. Only NSAID in suppository form
   2. Most potent NSAID (however this carries renal and GI risks)
4. Indications
   1. Acute Gouty Arthritis
   2. Ankylosing Spondylitis
   3. Pericarditis
   4. Bartter's Syndrome
   5. Preterm Labor (Tocolysis)
   6. Patent Ductus Arteriosus in the newborn
5. Contraindications
   1. Peptic Ulcer Disease
   2. Aspirin Sensitivity
   3. Renal Disease
   4. Coagulopathy
   5. Pregnancy beyond 30 weeks
   6. Childhood (except Patent Ductus Arteriosus)
   7. Dementia (consider avoiding in elderly)
6. Dosing: General Analgesic use
   1. Regular: 25-50 mg PO tid with food or milk
   2. Sustained Release: 75 mg PO qd to bid
   3. Maximum: 200 mg/day
7. Dosing Protocol: Preterm Labor
   1. Protocol 1
      1. Loading dose: 100 mg suppository rectally
      2. Maintenance: 25 mg PO every 6 hours for 24 hours
      3. Repeat for an additional 24 hours maximum
   2. Protocol 2
      1. Loading dose: 50 mg PO
      2. Maintenance: 25 mg PO every 4 hours for 24 hours
      3. Repeat for an additional 24 hours maximum
   3. Monitoring
      1. Amniotic Fluid Index biweekly for use >48 hours
8. Adverse Effects (more than other NSAIDs)
   1. Headache
   2. Peptic ulcer
   3. Gastrointestinal upset
   4. Fluid retention
   5. Prolonged Bleeding Time
   6. Nausea or Vomiting
   7. Pruritus
   8. Bowel changes
   9. Fetal effects
      1. Early ductus arteriosus closure
      2. Oligohydramnios
      3. Not linked to Intraventricular Hemorrhage
         1. Suarez (2001) Obstet Gynecol 97:921-5
   10. Nephrotoxic
       1. See Nephrotoxicity due to NSAIDs
9. Drug Interactions
   1. Lithium