Robenacoxib in the treatment of pain in cats and dogs: safety, efficacy, and place in therapy.

Robenacoxib is a novel nonsteroidal anti-inflammatory drug (NSAID) of coxib class developed for the control of inflammation and pain in dogs and cats. It shows high selectivity for the cyclooxygenase-2 (COX-2) enzyme in rats, cats, and dogs. Robenacoxib is available in both injectable and tablet formulations. This review initially focuses on the preclinical pharmacology of robenacoxib in rats that includes its high affinity for COX-2 enzyme and weaker and rapidly reversible binding for COX-1 enzyme in in vitro and ex vivo models of inflammation and its pharmacokinetics in the blood and inflammatory exudate, selective tissue distribution, and safety. These basic pharmacological profiles highlight the suitability of robenacoxib for use in target species, such as cats and dogs. Since the level of expression and activity of COX enzymes is species specific, COX-2-selective inhibition and the resultant effects of coxibs must be studied in target species. The pharmacological and toxicological profiles of robenacoxib in cats and dogs have been discussed prior to reviewing its clinical efficacy and safety. Large, multicenter field trials conducted in cats and dogs demonstrated the noninferior efficacy and safety of robenacoxib compared with noncoxib NSAIDs used in dogs and cats. These trials investigated the efficacy of robenacoxib against various acute and chronic painful conditions. Robenacoxib produced superior efficacy to placebo and COX-2 preferential inhibitors in postsurgical cats. The tissue-selective anti-inflammatory activity of robenacoxib has been demonstrated in dogs with osteoarthritis. Robenacoxib has also been shown to be safe in healthy dogs and cats receiving antihypertensive drugs and loop diuretics that could cause renal injury. The developmental objective of coxibs, comparable efficacy but superior safety to less selective/nonselective NSAIDs, is well established with robenacoxib in preclinical studies. More studies need to be conducted to fully explore the benefits of robenacoxib in clinical subjects.