Comparative analgetic testing of various compounds in mice using writhing techniques.

Anti-writhing assays to detect analgesia or specific activity against selected agonists were performed on albino mice. Acetylcholine Cl, bradykinin triacetate, phenylquinone, and serotonin creatinine sulfate were used as agonists. 10 compounds, including 5 standard analgetics, were tested against each agonist. Attempts to study histamine phosphate as an agonist were not successful. Results of these investigations showed satisfactory analgetic acitivity for codeine phosphate and acteyl salicylic acid (ASA) in all assays. weaker analgetics displayed varying degrees of activity depending on the agonist tested. Acute oral toxicities were determined for the 10 test compounds and the analgetic ED50 vs the LD50 of each compound was compared. The data confirmed the nonspecificity for writhing assays as well as a variability in activity of the test compounds against the various agonist.