NSAIDs

Nonsteroidal Anti-inflammatory Drugs
Nonsteroidal anti-inflammatory drugs (NSAID) include phenylbutazone, flunixin meglumine (Banamine), naproxen, meclofenamic acid and aspirin. Phenylbutazone has been the most commonly used due to its predictable action and it being inexpensive. NSAIDs work by inhibiting prostaglandins, which have been mentioned as significant factors both in causing damage to articular cartilage but also potentiating pain. Used at the correct dosage level, the side effects are minimal in adult animals. However, the drugs are toxic in foals and in ponies and should only be given in these situations when there is a critical need. Phenylbutazone will also cause problems in adults at high dose rates (4 gm/day). Toxic effects of NSAIDs include gastrointestinal ulceration and inflammation and nephrotoxicity (kidney toxicity). These agents are commonly used as the first line of drug therapy with joint injury. Phenylbutazone is used by the author for seven days after surgery to minimize inflammation. Some controlled work in humans has shown not only beneficial effects directly after surgery but also long term in terms of function and success rate. Failure to respond to nonsteroidal anti-inflammatory drugs is often an indication for further diagnostic examinations as well as the use of other medications, particularly intra-articular ones.