Indometacin (INN and BAN) or indomethacin (AAN, USAN, and former BAN) is a nonsteroidal anti-inflammatory drug (NSAID) commonly used as a prescription medication to reduce fever, pain, stiffness, and swelling from inflammation. Indomethacin has analgesic, anti-inflammatory, and antipyretic properties. The mechanism of action of Indometacin, like that of other NSAIDs, is not completely understood but involves inhibition of cyclooxygenase (COX-1 and COX-2). Indomethacin is a potent inhibitor of prostaglandin synthesis in vitro. Indomethacin concentrations reached during therapy have produced in vivo effects. Prostaglandins sensitize afferent nerves and potentiate the action of bradykinin in inducing pain in animal models. Prostaglandins are mediators of inflammation. Because indomethacin is an inhibitor of prostaglandin synthesis, its mode of action may be due to a decrease of prostaglandins in peripheral tissues. Indometacin is indicated for: Moderate to severe rheumatoid arthritis including acute flares of chronic disease, Moderate to severe ankylosing spondylitis, Moderate to severe osteoarthritis, Acute painful shoulder (bursitis and/or tendinitis), Acute gouty arthritis. In general, adverse effects seen with indomethacin are similar to all other NSAIDs. For instance, indometacin inhibits both cyclooxygenase-1 and cyclooxygenase-2, it inhibits the production of prostaglandins in the stomach and intestines, which maintain the mucous lining of the gastrointestinal tract. Indometacin, therefore, like other non-selective COX inhibitors can cause peptic ulcers. These ulcers can result in serious bleeding and/or perforation requiring hospitalization of the patient. To reduce the possibility of peptic ulcers, indomethacin should be prescribed at the lowest dosage needed to achieve a therapeutic effect, usually between 50–200 mg/day. It should always be taken with food. Nearly all patients benefit from an ulcer protective drug (e.g. highly dosed antacids, ranitidine 150 mg at bedtime, or omeprazole 20 mg at bedtime). Other common gastrointestinal complaints, including dyspepsia, heartburn and mild diarrhea are less serious and rarely require discontinuation of indomethacin.

Cimicoxib is a selective cyclooxygenase 2 inhibitor used in veterinary medicine to treat dogs for pain and inflammation associated with osteoarthritis and for the management of pain and inflammation associated with surgery. Limited data are available on cimicoxib, with one study documenting non-inferiority compared to carprofen in managing postoperative pain for dogs undergoing either orthopedic or soft tissue surgery. There are some data available as part of cimicoxib’s approval process in Europe to support its use for chronic pain.

3-Aminopropionitrile (beta-aminopropionitrile, BAPN) is a poisonous substance found in Lathyrus spp. (wild peas), for example, Lathyrus hirsutus (wild winter pea), sometimes sown with grasses to provide early-spring grazing. BAPN is a specific and irreversible inhibitor of LOX activity. It has been shown to reduce body weight gain and improve the metabolic profile in diet-induced obesity in rats. The administration of beta-aminopropionitrile has been proposed for pharmacological control of unwanted scar tissue in human beings. BAPN has been shown to have preventive effect in the development of fibrosis by decreasing tissue damage in an experimental model of corrosive esophagitis in rats. BAPN is FDA approved for the treatment of tendinitis of the superficial digital flexor tendon (SDFT) in horses where there is sonographic evidence of fiber tearing.

Rofecoxib is a nonsteroidal anti-inflammatory drug which selectively inhibits COX-2 and subsequent prostaglandin synthesis. The drug was developed by Merk and approved by FDA in 1999 for relief of signs and symptoms of arthritis, acute pain in adults, and painful menstrual cycles under the name Vioxx. Later on Merck voluntarily withdrawn Vioxx from the market due to safety concerns (high risk of heart attack and stroke).

Carprofen is an anti-inflammatory drug developed in Japan by Nippon Roche Research Center. Carprofen, as many NSAIDs, selectively inhibits COX-2 and was shown to suppress inflammation in vitro, using osteoarthritis models. The drug was approved by FDA for human use under the name Ridamyl, however, now it is sold only for veterinary purposes and prescribed for the treatment of postoperative pain and the relief of pain and inflammation associated with osteoarthritis in dogs.

Suprafen is a dual inhibitor of COX-1 and COX-2, which was used for the inhibition of intraoperative miosis. Suprafen was marketed under the name Profenal, however, it is no longer available in the USA.

BENOXAPROFEN is an anti-inflammatory drug indicated for the treatment of arthritis. It was marketed under the brand name ORAFLEX® in the US and as OPREN® in Europe by Eli Lilly and Company. In 1982 Eli Lilly voluntarily withdrew BENOXAPROFEN from the market due to postmarketing reports of severe liver toxicity in patients who took it.

Aurothioglucose (trade name Solganal), also known as gold thioglucose, is a glucose derivative formerly used to treat rheumatoid arthritis, that cannot be adequately controlled by other medicines. Aurothioglucose has been shown to inhibit protein kinase C, a metalloenzyme containing Zn(2+) bound to cysteine and histidine residues, which plays a crucial role in intracellular signal transduction by phosphorylating serine/threonine residues in the protein. The inhibition of protein kinase C has been suggested as a possible mode of action for the therapeutic antirheumatic action of gold drugs. In 2001, aurothioglucose was withdrawn from the Dutch market, where it had been the only injectable gold preparation available since 1943, forcing hospitals to change medication for a large number of patients to aurothiomalate. The drug had been in use for more than 70 years, and four years later the reasons for its sudden disappearance remained unclear.

Oxaceprol, a structural analog of hydroxyproline, has been used for several years for the treatment of osteoarthritis and rheumatoid arthritis, showing good gastrointestinal safety, particularly in comparison with NSAIDs. It was shown that oxaceprol does not inhibit the synthesis of prostaglandins in vitro, but acts predominantly by inhibiting leukocyte adhesion and migration, thus inhibiting inflammation at an early stage and helps in pain relief.

Robenacoxib (trade name Onsior) is a non-steroidal anti-inflammatory drug (NSAID) used in veterinary medicine for the relief of pain and inflammation in cats and dogs. In an inflammation model in cats, Robenacoxib had analgesic, anti-inflammatory and antipyretic actions with a rapid onset of action (0.5 h). In an in vitro whole blood assay in cats, Robenacoxib demonstrated selective COX-2 inhibition. After oral administration of robenacoxib tablets at 1 mg/kg without food, peak blood concentrations are attained rapidly with a median Tmax of 0.5 h, a mean Cmax of 1159 ng/ml and a mean AUC of 1337 ng*h/ml. Robenacoxib persists longer in the inflammatory exudate of a tissue cage model than in blood. The median Robenacoxib elimination half-life in exudate was about 27 hours versus 2.5 hours for blood. Robenacoxib is extensively metabolized by the liver in cats. The systemic exposure of lactam metabolite is about 25% of Robenacoxib exposure following oral administration to fed cats. Further, the systemic exposure to lactam appears to be two-fold greater in fed cats than fasted cats. Apart from one lactam metabolite, the identity of other metabolites is not known in cats.