A COMPARISON OF THE CARDIOVASCULAR EFFECTS OF LEVOBUPIVACAINE AND RAC-BUPIVACAINE FOLLOWING INTRAVENOUS ADMINISTRATION TO HEALTHY-VOLUNTEERS

Aims The aim of this study was to compare the cardiovascular effects o f levobupivacaine with those of rac-bupivacaine following i.v. adminis tration to 14 healthy male volunteers. Methods Drugs were infused (at 10 mg min(-1)) using a randomized, double-blind, complete crossover pr ocedure with a washout period of at least 1 week. The administration o f drug was discontinued on the appearance of defined CNS symptoms or w hen a total of 150 mg had been given. Parameters measured were arteria l blood pressure, heart rate, EGG, ejection fraction, acceleration ind ex, stroke index and cardiac index. Results The mean doses administere d were 56.1 mg and 47.9 mg for levobupivacaine and rac-bupivacaine res pectively and the maximum mean plasma concentrations were 2.62 and 2.2 5 mu g ml(-1) respectively. Despite the dose and plasma concentrations being comparable, levobupivacaine produced a statistically significan t smaller reduction in mean stroke index (-5.14 vs -11.86 ml m(-2) P=0 .001), acceleration index (-0.09 vs -0.20 s(-2) P=0.011) and the eject ion fraction (-2.50 vs -4.29%, P=0.024). Both levobupivacaine (non sig nificant) and rac-bupivacaine (significant) produced small increases i n the PR interval and the corrected QT interval and although the effec ts of udc-bupivacaine appeared to be greater the difference between th e two drugs was not significant. Conclusions In conclusion, this study has shown that following i.v. administration levobupivacaine produces significantly less effects on cardiovascular function than does rac-b upivacaine. In particular the negative inotropic effect for levobupiva caine was less than that for rac-bupivacaine as indicated by changes i n stroke index, acceleration index and ejection fraction.