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 of levobupivacaine with those of rac-bupivacaine following i.v. administration to 14 healthy male volunteers. METHODS: Drugs were infused (at 10 mg min(-1)) using a randomized, double-blind, complete crossover procedure with a washout period of at least 1 week. The administration of drug was discontinued on the appearance of defined CNS symptoms or when a total of 150 mg had been given. Parameters measured were arterial blood pressure, heart rate, ECG, ejection fraction, acceleration index, stroke index and cardiac index. RESULTS: The mean doses administered were 56.1 mg and 47.9 mg for levobupivacaine and rac-bupivacaine respectively and the maximum mean plasma concentrations were 2.62 and 2.25 microg ml(-1) respectively. Despite the dose and plasma concentrations being comparable, levobupivacaine produced a statistically significant 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 ejection fraction (-2.50 vs -4.29%, P=0.024). Both levobupivacaine (non significant) and rac-bupivacaine (significant) produced small increases in the PR interval and the corrected QT interval and although the effects of rac-bupivacaine appeared to be greater the difference between the 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-bupivacaine. In particular the negative inotropic effect for levobupivacaine was less than that for rac-bupivacaine as indicated by changes in stroke index, acceleration index and ejection fraction.

The local anaesthetic activity of levobupivacaine does not differ from racemic bupivacaine (Marcain): first clinical evidence.

The local anaesthetic efficacy of levobupivacaine was compared with racemic bupivacaine (Marcain) in healthy male volunteers who were undergoing ulnar nerve blockade. Levobupivacaine, like racemic bupivacaine, produced blockade of nerve function with evidence of a dose response relationship for levobupivacaine. There were no statistically significant differences with respect to duration of sensory pain, sensory touch or motor block when the adjusted mean for the levobupivacaine groups (0.125, 0.25 and 0.5%) were compared with the 0.25% racemic bupivacaine control group. It is concluded that levobupivacaine is an effective local anaesthetic in humans with a dose-related duration of effect. Its local anaesthetic effect did not differ from that of racemic bupivacaine.

The binding of the benzimidazole dye H8208 to DNA and to polyinosinic-polycytidylic acid.

The benzimidazole dye H8208 (2-(4-aminophenyl)-5-(4-methylpiperazin-1-yl) benzimidazole) has been shown to intercalate into calf thymus DNA and into polyinosinic-polycytidylic acid (a model for A conformation DNA) by a variety of spectroscopic techniques. The binding affinity of the dye was found to be similar to both nucleic acids.