Abstract

Ketorolac is a potent non-steroidal anti-inflammatory drug widely used for short-term pain management; however, its clinical application is limited by dose-related toxicity. The present study investigated the acute oral toxicity (LD₅₀) of ketorolac in albino mice and evaluated its peripheral analgesic activity in comparison with acetaminophen using a standardized experimental pain model. Acute toxicity was determined using the up-and-down method, after which mice were randomly assigned to three groups (n = 5): ketorolac-treated, acetaminophen-treated, and control. The drugs were administered orally at therapeutic doses for five consecutive days, and analgesic activity was assessed using the acetic acid–induced writhing test. Ketorolac produced dose-dependent toxic manifestations, with an estimated LD₅₀ of 474.82 mg/kg body weight. In the writhing assay, ketorolac significantly reduced the number of abdominal constrictions compared with both acetaminophen and control groups (P < 0.05). These findings indicate that ketorolac exhibits stronger peripheral analgesic activity than acetaminophen, accompanied by measurable acute toxicity at higher doses, highlighting the importance of interpreting analgesic efficacy in relation to safety parameters.

Key words: Keywords: Ketorolac, Acetaminophen, Acute toxicity, LD50 ,Analgesic Activity, Writhing test.