ACUTE TOXICITY OF BUPIVACAINE METABOLITES IN MICE

1. This study was designed to document the acute toxicity of two metab olites of bupivacaine, desbutylbupivacaine (2,6, desbutylbupivacaine; PPX) and pipecolic acid in mice. All the compounds were administered b y the intraperitoneal (i.p.) route. 2. The mean convulsant activity wa s 100% for controls, 30, 100, 100, 100 and 90% for 400, 200, 150, 125 and 112.5 mg/kg i.p. of PPX, respectively, and 0% for the animals rece iving pipecolic acid. 3. The acute induced mortality was 60% for bupiv acaine control group (50 mg/kg/i.p.), 60, 30 and 0% for 800, 400 and 2 00 mg/kg of pipecolic acid, respectively, and 100, 90, 60, 80 and 10% for 400, 200, 150, 125 and 112.5 mg/kg i.p. of PPX, respectively. 4. T he time to convulse was 158 +/- 16 s for bupivacaine, 230 +/- 30, 270 +/- 24, 255 +/- 21, 442 +/- 84 and 418 +/- 32 s for 200, 150, 125, 112 .5 and 100 mg/kg i.p. of PPX, respectively; any pipecolic acid treated animal have convulsed. 5. In conclusion, the present study demonstrat ed that PPX is more toxic than expected since we found that its induce d mortality was approximately three times that found for bupivacaine a nd its CNS toxicity was about two times that of bupivacaine.