Systemic absorption and gastrointestinal adverse effects from topical ketorolac and diclofenac ophthalmic solutions in healthy dogs

Abstract

OBJECTIVE To investigate systemic absorption and gastrointestinal (GI) adverse effects of topical ketorolac 0.5% and diclofenac 0.1% ophthalmic solutions. ANIMALS 11 healthy purpose-bred Beagles. METHODS Dogs were randomly assigned to receive either ketorolac (n = 6) or diclofenac (5), 1 drop in both eyes 4 times daily for 28 days. Upper GI endoscopy was performed on days 0 and 29 with mucosal lesion scores (0 to 7) assigned to each region evaluated. Plasma samples were collected on days 14, 21, and 28 for measurement of diclofenac and ketorolac using high-performance liquid chromatography–mass spectrometry. RESULTS GI erosions and/or ulcers developed in all ketorolac-treated dogs and 1 of 5 diclofenac-treated dogs. Post-treatment mucosal lesion score for the antrum was higher in the ketorolac group than in the diclofenac group (P = .006) but not significantly different for any other region. Post-treatment antral mucosal lesion scores were significantly related to plasma ketorolac concentrations (P