Tebufelone (formerly NE-11740) is a member of the di-tert-butyl-phenol anti-inflammatory agents. Tebufelone is a dual cyclooxygenase (CO)/5-lipoxygenase (LO) inhibitor that has potent analgesic, antipyretic, and anti-inflammatory effects. This drug was studied for the treatment of rheumatic disorders; however, this study was discontinued.

Anilopam is an opioid analgesic of the benzazepine class. It is an opioid receptor agonist.

Acequinoline (CB 4985) is an analgesic, antiinflammatory agent. It is also antirheumatic, antigout (antimalarial).

Acefurtiamine is a vitamin B1 analog. It is as an analgesic.

Sudoxicam is a nonsteroidal anti-inflammatory drug patented by American multinational pharmaceutical corporation Pfizer for the treatment of thrombosis. Sudoxicam strongly inhibited aggregation of rabbit, dog, and human platelets caused by collagen, but not by ADP. Sudoxicam inhibited the secondary phase of the biphasic response of guinea pig platelets to ADP and suppressed the release of ADP from human platelets caused by collagen. Sudoxicam shows superior anti-inflammatory activity compare to indomethacin in rat paw edema model. In clinical trials, sudoxicam was associated with several cases of severe hepatotoxicity that led to its discontinuation.

Tiopinac is a tricyclic compound with anti-inflammatory and analgesic effects in animals, ability to inhibit prostaglandin synthesis, and modest antiplatelet aggregation properties in humans. The manufacturer withdrew tiopinac from investigation because of toxicity at higher doses. Tiopinac did not have significant cardiovascular or CNS activity. Lack of anorexia and emesis in dogs with up to 30 mg/kg p.o. and mild oral activity in producing gastric erosion in acute and subacute studies in rats suggests that tiopinac may have relatively little gastrointestinal irritating activity.

Metazamide is an imidazolone derivative exerting analgesic properties. It affects glucose utilization and activity of glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase and malate dehydrogenase in rat erythrocytes.

Flazalone is a nonsteroidal anti-inflammatory drug. In acute irritant anti-inflammatory tests, flazalone exhibited a wide spectrum of activity. The compound was active in affecting the course of paw swelling in adjuvant arthritis when given daily either at the outset of the polyarthritis or after induction. The most unusual aspect of this compound is its ability to inhibit graft rejection in goldfish and rabbits.

Letimide is a new analgesic. It is a cyclic derivative of a salicylamide. The analgesic effect of this drug as determined in rats showed a higher potency than aspirin, but was without anti-inflammatory and antipyretic activity. Letimide is not a genotoxic agent according to the cytogenetic damage observed in vivo and in vitro, and would seem to justify other preclinical and clinical studies to confirm its lack of toxicity. Known adverse effects are headache and dizziness.

Furobufen, a propionic acid derivative produced anti-inflammatory, antiarthritic, and antipyretic effects. It was shown that this compound could reduce the pain resulting from an acute inflammatory reaction and the activity profile of furobufen was similar to that of the non-steroidal anti-inflammatory drugs. Information about the current development of this compound is not available.