58% of an administered dose is excreted as unchanged drug. Ketorolac is not an inhibitor or inducer of hepatic enzymes in vivo. Risk for gastrointestinal adverse events in the form of nausea and diarrhoea motivates vigilance against insufficient intake of food, especially of carbohydrate.

Ketorolac is a pyrrolizine carboxylic acid derivative and a non-steroidal anti-inflammatory drug.

S-(-)-ketorolac is the enantiomer which have the analgesic effect. Common side effects that can be potentially porphyrinogenic through reduction in carbohydrate intake and that also can be confused with an acute porphyria attack are nausea, dyspepsia, gastrointestinal pain and diarrhoea.

Ketorolac is metabolised to p-hydroxy ketorolac which is inactive. 91% of ketorolac and its metabolites are excreted in urine. 58% is excreted as unchanged drug and 31% as p-hydroxy ketorolac and 31% as conjugate (SPC). Terminal half-life is 4-6 hours, 6-7 hours in the elderly, and 9-10 h in renal dysfunction. There is no evidence in human studies that ketorolac trometamol induces or inhibits the hepatic enzymes capable of metabolising itself or other drugs (SPC).

Use with extreme caution only. There are however, no published data on ketorolac. The recommendation is based on a comparison with drug of the same class (James 2000).

Uneventful use reported in 1 patient with acute porphyria.