Oxicam

Piroxicam

Oxicam is a class of non-steroidal anti-inflammatory drugs (NSAIDs) that bind closely to plasma proteins.^[1] Most oxicams are unselective inhibitors of the cyclooxygenase (COX) enzymes. The exception is meloxicam with a slight (10:1) preference for COX-2, which, however, is only clinically relevant at low doses.^[2]

Examples include:

• Ampiroxicam
• Piroxicam
• Tenoxicam
• Droxicam
• Lornoxicam
• Meloxicam
• Isoxicam

Chemistry

The physico-chemical characteristics of these molecules vary greatly depending upon the environment.^[3]

In contrast to most other NSAIDs, oxicams are not carboxylic acids. They are tautomeric and can exist as number of tautomers (keto-enol tautomerism), here exemplified by piroxicam:^[4]

References

1. Olkkola KT, Brunetto AV, Mattila MJ (1994). "Pharmacokinetics of oxicam nonsteroidal anti-inflammatory agents". Clinical pharmacokinetics. 26 (2): 107–20. doi:10.2165/00003088-199426020-00004. PMID 8162655.
2. Mutschler, Ernst; Gerd Geisslinger; Heyo K. Kroemer; Monika Schäfer-Korting (2001). Arzneimittelwirkungen (in German) (8 ed.). Stuttgart: Wissenschaftliche Verlagsgesellschaft. p. 233. ISBN 3-8047-1763-2.
3. Banerjee R, Chakraborty H, Sarkar M (2003). "Photophysical studies of oxicam group of NSAIDs: piroxicam, meloxicam and tenoxicam". Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy. 59 (6): 1213–22. doi:10.1016/S1386-1425(02)00300-1. PMID 12659890.
4. Ivanova D, Deneva V, Nedeltcheva D, Kamounah FS, Gergov G, Hansen PE, Kawauchi S, Antonov L (2015). "Tautomeric transformations of piroxicam in solution: a combined experimental and theoretical study". RSC Advances. 5: 31852–31860.