A pyrrolizine carboxylic acid derivative structurally related to indomethacin. It is an NSAID and is used principally for its analgesic activity. (From Martindale The Extra Pharmacopoeia, 31st ed)
Indication
For the short-term (~5 days) management of moderately severe acute pain that requires analgesia at the opioid level, usually in a postoperative setting.
Pharmacology
Ketorolac, an antiinflammatory agent with analgesic and antipyretic properties, is used to treat osteoarthritis and control acute pain. It is a peripherally acting analgesic. The biological activity of ketorolac tromethamine is associated with the S-form. Ketorolac tromethamine possesses no sedative or anxiolytic properties.
Toxicity
LD50 = 189 mg/kg (rat, oral).
Affected Organisms
Humans and other mammals
Biotransformation
Primarily hepatic. Less than 50% of a dose is metabolized. The major metabolites are a glucuronide conjugate, which may also be formed in the kidney, and p-hydroxy ketorolac. Neither metabolite has significant analgesic activity.
Absorption
Rapidly and completely absorbed after oral administration
Half Life
2.5 hours for the S-enantiomer compared with 5 hours for the R-enantiomer
Protein Binding
99%
Elimination
The principal route of elimination of ketorolac and its metabolites is renal. Approximately 6% of a dose is excreted in the feces.
A racemate comprising equimolar amounts of (R)-(+)- and (S)-(-)-5-benzoyl-2,3-dihydro-1H-pyrrolizine-1-carboxylic acid. While only the (S)-(-) enantiomer is a COX1 and COX2 inhibitor, the (R)-(+) enantiomer exhibits potent analgesic activity. A non-steroidal anti-inflammatory drug, ketorolac is mainly used (generally as the tromethamine salt) for its potent analgesic properties in the short-term management of post-operative pain, and in eye drops to relieve the ocular itching associated with seasonal allergic conjunctivitis. It was withdrawn from the market in many countries in 1993 following association with haemorrhage and renal failure.
A member of the class of pyrrolizines that is 2,3-dihydro-1H-pyrrolizine which is substituted at positions 1 and 5 by carboxy and benzoyl groups, respectively.
