Tolmetin sodium is an effective NSAID approved and marketed for the treatment of rheumatoid arthritis, osteoarthritis and juvenile rheumatoid arthritis. In humans, tolmetin sodium is absorbed rapidly with peak plasma levels observed 30 min after p.o. administration, but it is also eliminated rapidly with a mean plasma elimination t½ of approximately 1 hr. The preparation of slow release formulations or chemical modification of NSAIDs to form prodrugs has been suggested as a method to reduce the gastrotoxicity of these agents.
Amtolmetin guacil is a non-acidic prodrug of tolmetin, having similar NSAID properties like tolmetin with additional analgesic, antipyretic, and gastro protective properties. Amtolmetin is formed by amidation of tolmetin by glycine
Amtolmetin guacil stimulates capsaicin receptors present on gastro intestinal walls, because of presence of vanillic moiety and also releases NO which is gastro protective. It also inhibits prostaglandin synthesis and cyclooxygenase (COX).