Nonsteroidal anti-inflammatory drugs in birds: pharmacokinetics, pharmacodynamics and toxicity

Non-steroidal anti-inflammatory drugs (NSAIDs) prevent conversion of arachidonic acid into prostanoids by inhibiting the cyclo-oxygenase isoenzymes. In humans and animals, NSAIDs are primarily used as an analgesic and anti-inflammatory agent in diseases of the joints, skeleton and muscles, for treatment of abdominal pain and, to a lesser extent, for post-operative pain. The pharmacokinetics, pharmacodynamics and toxicity of NSAIDs strongly vary between types of NSAIDs, animal species and even within bird species (passerines, psittacines, raptors, waterfowl, gallifoimes and pigeons). Species-specific differences in pharmacokinetic processes (absorption, distribution, metabolization and excretion) make it difficult to extrapolate results among the different bird species. Pharmacodynamic studies demonstrate that effective doses are also species dependent, which in turn illustrates the importance to perform phaimacodynamic studies in the animal of interest. Most side effects of NSAIDs in birds are associated with nefrotoxicity, muscle necrosis and gastro-intestinal toxicity. It is important to take these pharmacological and toxicological characteristics into account when using NSAIDs in birds.