Ketorolac is a pyrrolizine carboxylic acid derivative structurally related to indomethacin. It is an NSAID and is used principally for its analgesic activity and has been shown to decrease opioid requirements in post-operative patients. It does not affect consciousness or respiration but does have effects on gastric mucosa, renal perfusion, and platelet function. Ketorolac tromethamine ophthalmic solution is sold under brand name acular LS and is indicated for the reduction of ocular pain and burning/stinging following corneal refractive surgery. Ketorolac tromethamine is a racemic mixture of [-]S- and [ ]R-enantiomeric forms, with the S-form having analgesic activity. Its antiinflammatory effects are believed to be due to inhibition of both cylooxygenase-1 (COX-1) and cylooxygenase-2 (COX-2) which leads to the inhibition of prostaglandin synthesis leading to decreased formation of precursors of prostaglandins and thromboxanes from arachidonic acid. The resultant reduction in prostaglandin synthesis and activity may be at least partially responsible for many of the adverse, as well as the therapeutic, effects of these medication. Analgesia is probably produced via a peripheral action in which blockade of pain impulse generation results from decreased prostaglandin activity.

Meloxicam (brand name Mobic) is an nonsteroidal anti-inflammatory drug (NSAID) with analgesic and antipyretic properties. Mobic is indicated for the relief of the signs and symptoms of osteoarthritis and rheumatoid arthritis, and has been available in the U.S. since June 2000. The mechanism of action like that of other NSAIDs, is not completely understood but involves inhibition of cyclooxygenase (COX-1 and COX-2). Meloxicam 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 meloxicam is an inhibitor of prostaglandin synthesis, its mode of action may be due to a decrease of prostaglandins in peripheral tissues. MOBIC is contraindicated in patients who have experienced asthma, itching or allergic type reactions after taking aspirin or other NSAIDs. Severe, rarely fatal, anaphylactic-like reactions to NSAIDs have been reported in such patients. As with all NSAIDs, serious GI toxicity such as inflammation, bleeding, ulceration, and perforation of the stomach, small intestine, or large intestine can occur at any time, without symptoms. As with other NSAIDs, meloxicam is not indicated for prevention of thromboembolic events and is not a substitute for aspirin or other drugs indicated for cardiovascular prophylaxis. It was developed by Boehringer Ingelheim and is co-marketed with Abbott Laboratories. Meloxicam is also used in the veterinary field, most commonly in dogs and cats, but also sees off-label use in other animals such as cattle and exotics

Celecoxib is a nonsteroidal anti-inflammatory drug (NSAID). It works by reducing hormones that cause inflammation and pain in the body. Celecoxib is an analgesic that is FDA approved for the treatment of osteoarthritis，rheumatoid arthritis，juvenile rheumatoid arthritis, ankylosing, spondylitis, acute pain and primary dysmenorrhea. The mechanism of action of Celecoxib is believed to be due to inhibition of prostaglandin synthesis, primarily via inhibition of cyclooxygenase-2 (COX-2). Concomitant use of Celecoxib and analgesic doses of aspirin is not generally recommended. Concomitant use with Celecoxib may diminish the antihypertensive effect of ACE Inhibitors, Angiotensin Receptor Blockers (ARB), or BetaBlockers and can increase serum concentration and prolong half-life of digoxin. Common adverse reactions include hypertension, diarrhea, nausea and headache.

Nabumetone is a naphthylalkanone. Is is a non-selective prostaglandin G/H synthase (a.k.a. cyclooxygenase or COX) inhibitor that acts on both prostaglandin G/H synthase 1 and 2 (COX-1 and -2). Prostaglandin G/H synthase catalyzes the conversion of arachidonic acid to prostaglandin G2 and prostaglandin G2 to prostaglandin H2. Prostaglandin H2 is the precursor to a number of prostaglandins involved in fever, pain, swelling, inflammation, and platelet aggregation. The parent compound is a prodrug that undergoes hepatic biotransformation to the active compound, 6-methoxy-2-naphthylacetic acid (6MNA). The analgesic, antipyretic and anti-inflammatory effects of NSAIDs occur as a result of decreased prostaglandin synthesis. The parent compound is a prodrug, which undergoes hepatic biotransformation to the active component, 6-methoxy-2-naphthylacetic acid (6MNA), that is a potent inhibitor of prostaglandin synthesis, most likely through binding to the COX-2 and COX-1 receptors. Nabumetone is used for acute and chronic treatment of signs and symptoms of osteoarthritis and rheumatoid arthritis. Nabumetone has been developed by Beecham. It is available under numerous brand names, such as Relafen, Relifex, and Gambaran.

Piroxicam is in a class of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). It was originally brought to market by Pfizer under the tradename Feldene in 1980, became generic in 1992, and is marketed worldwide under many brandnames. Piroxicam works by reducing hormones that cause inflammation and pain in the body. Piroxicam is used to reduce the pain, inflammation, and stiffness caused by rheumatoid arthritis and osteoarthritis. The antiinflammatory effect of Piroxicam may result from the reversible inhibition of cyclooxygenase, causing the peripheral inhibition of prostaglandin synthesis. The prostaglandins are produced by an enzyme called Cox-1. Piroxicam blocks the Cox-1 enzyme, resulting into the disruption of production of prostaglandins. Piroxicam also inhibits the migration of leukocytes into sites of inflammation and prevents the formation of thromboxane A2, an aggregating agent, by the platelets. Piroxicam is used for treatment of osteoarthritis and rheumatoid arthritis.

(R)- enantiomer does not exhibit COX inhibition – it was > 100-fold less active than (S)- enantiomer on both COX subtypes. (R)- enantiomer is about 60 times less potent than the (-)-S isomer in the carrageenan edema test and ca. 230 times less active than the (-)-S isomer in the mouse phenylquinone writhing assay. R-ketorolac is an inhibitor of fatty acid amide hydrolase, but not at physiological concentrations.

(S)-ketorolac is the enantiomer of ketorolac, a nonsteroidal anti-inflammatory drug. (S)-ketorolac exhibited potent cyclooxygenase (COX1 and COX2) enzyme inhibition. (S)-ketorolac is considered to be active enantiomer of racemic ketorolac.