Analgesic

Salicylate

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Salicylate

  • See Also
  1. Salicylate Overdose (Salicylism)
  2. Nonsteroidal Anti-inflammatory
  • Mechanism
  1. History
    1. Willow bark and wintergreen leaves contain Salicin (Salicylic acid)
      1. Used for thousands of years for pain and fever
      2. Salicylic acid was first lab synthesized in the 1840s
      3. Salicylic acid was acetylated to the more palatable Acetylsalicylic Acid (Aspirin) in the 1850s
    2. Salicylates have been used for pain, fever and rheumatic diseases for more than 100 years
      1. NSAIDs developed over time as a class of Aspirin-like drugs
      2. Most Salicylates are metabolized to the active salicylic acid
  2. Salicylates have antipyretic, Analgesic and anti-inflammatory properties
    1. Blocks cyclooxygenase (COX, esp. COX1)
    2. Inhibits conversion of Arachidonic Acid to Prostaglandin precursors
    3. Decreasing Prostaglanding levels results in decreased fever, pain and inflammation
  3. Salicylates (esp. Aspirin) also have antiplatelet activity
  • Medications
  1. Acetylsalicylic Acid (Aspirin)
    1. Analgesic Dosing: 500-1000 mg every 4-6 hours
  2. Other less commonly used Salicylates
    1. Trisalicylate (Trilisate)
      1. Dosing 1000-1500 mg every 8-12 hours
    2. Diflunisal (Dolobid) 500 mg every 8-12 hours
      1. Risk of Acute Interstitial Nephritis
      2. Compared with Aspirin, lower risk of Gastrointestinal Bleeding, Tinnitus
    3. Salsalate (Disalcid)
      1. Arthritis (OA, RA): 3000 mg/day divided every 8 to 12 hours
  3. Other Salicylates not in use medically
    1. Sodium Salicylate (Uracil 5)
    2. Sodium thiosalicylate (Tusal)
      1. Thimerosal (historically a Vaccine preservative) is a Mercury compound derived from thiosalicylic acid
  • Adverse Effects
  1. Gastrointestinal upset
  2. Gastrointestinal Bleeding
  3. Tinnitus
  4. Hypersensitivity
  5. Serious skin reactions (e.g. Stevens-Johnson Syndrome)
  • Safety
  1. Avoid Salicylates in general in Lactation
  2. Most Salicylates, as with NSAIDs are legacy system Pregnancy category C (except Category D in third trimester)
    1. Aspirin is used in pregnancy for Preeclampsia Prevention
  3. However Salicylates and NSAIDs have significant risks in pregnancy
    1. See NSAID for pregnancy-related risks that also apply to Salicylates
    2. Salicylates have specifically been found to have adverse effects in pregnancy
      1. Anemia
      2. Anti-partum Hemorrhage
      3. Post-partum Hemorrhage
      4. Prolonged gestation
      5. Complicated deliveries
      6. Perinatal mortality
      7. Collins (1975) Lancet 2(7930):335-8 +PMID: 51142 [PubMed]