Ketorolac, an injectable nonnarcotic analgesic

Abstract

Clinical studies of the injectable nonsteroidal anti-inflammatory agent (NSAIA) ketorolac tromethamine are reviewed, and the chemistry, pharmacology, pharmacokinetics, drug interactions, and adverse effects of ketorolac are described. Ketorolac exhibits anti-inflammatory, analgesic, and antipyretic activity. Although the exact mechanisms of action have not been determined, its effects appear to be associated principally with the inhibition of prostaglandin synthesis. After oral, i.m., or i.v. administration, ketorolac and its metabolites are excreted mainly in urine. Ketorolac tromethamine has been used for the symptomatic relief of moderate to severe postoperative pain, including that associated with abdominal, gynecologic, oral, orthopedic, or urologic surgery. Ketorolac has also been used for the relief of acute renal colic, pain associated with trauma, and visceral pain associated with cancer. When administered i.m., ketorolac produced analgesia comparable to that of i.m. doses of meperidine, pentazocine, or morphine. The most common adverse effects associated with short-term administration are nervous system and gastrointestinal effects; these are usually mild and occur in about 39% of patients. Unlike opiate analgesics, ketorolac does not appear to cause tolerance or physical dependence in patients receiving long-term therapy. Ketorolac tromethamine has been administered concomitantly with morphine or meperidine without apparent adverse interaction. For short-term pain management, an initial i.m. ketorolac tromethamine loading dose of 30 or 60 mg is recommended. Ketorolac tromethamine appears to be as effective as morphine or meperidine for short-term management of moderate to severe postoperative pain. It lacks the respiratory depressant effects of opiate analgesics but shares the toxic potentials of other NSAIAs.