S A Grant1, R S Hoffman, L R Goldfrank. 1. Department of Emergency Medicine, Long Island Jewish Medical Center, New Hyde Park, New York.
Abstract
STUDY HYPOTHESIS: Tetracaine will enhance cocaine toxicity. STUDY POPULATION: Two hundred forty female Swiss albino mice weighing 27 to 45 g. METHODS: Intraperitoneal injections of tetracaine and cocaine were given to groups of ten mice each in a controlled, blinded fashion. Either tetracaine or an equal volume of normal saline was given five minutes before one of six incremental doses of cocaine, ranging from 60 to 110 mg/kg. The experiment was repeated twice using two different doses of tetracaine: either an LD10 (40 mg/kg determined from preliminary studies), or one-twentieth of the dose of cocaine (which approximates the ratio used in tetracaine, epinephrine, and cocaine). Lethality was recorded at 24 hours. Lethality between groups was compared with a Wilcoxon sign-rank test. RESULTS: Tetracaine reduced cocaine lethality at all doses. This reduction in lethality was statistically significant at both tetracaine doses (P < .05). CONCLUSION: In the mouse, pretreatment with tetracaine significantly decreases cocaine lethality.
STUDY HYPOTHESIS: Tetracaine will enhance cocainetoxicity. STUDY POPULATION: Two hundred forty female Swiss albino mice weighing 27 to 45 g. METHODS: Intraperitoneal injections of tetracaine and cocaine were given to groups of ten mice each in a controlled, blinded fashion. Either tetracaine or an equal volume of normal saline was given five minutes before one of six incremental doses of cocaine, ranging from 60 to 110 mg/kg. The experiment was repeated twice using two different doses of tetracaine: either an LD10 (40 mg/kg determined from preliminary studies), or one-twentieth of the dose of cocaine (which approximates the ratio used in tetracaine, epinephrine, and cocaine). Lethality was recorded at 24 hours. Lethality between groups was compared with a Wilcoxon sign-rank test. RESULTS:Tetracaine reduced cocaine lethality at all doses. This reduction in lethality was statistically significant at both tetracaine doses (P < .05). CONCLUSION: In the mouse, pretreatment with tetracaine significantly decreases cocaine lethality.