Toleration of intravenous azithromycin.

OBJECTIVE

To study the toleration of various infusate concentrations of single intravenous doses of azithromycin.

DESIGN

Randomized, double-blind, two-treatment, two-period, crossover.

SETTING

Clinical pharmacology unit.

PARTICIPANTS

Twenty-four healthy men aged 19-41 years.

STUDY DESIGN

All subjects were initially randomized to receive single 1-hour intravenous infusions of azithromycin 1 g at infusate concentrations of 1, 2, or 5 mg/mL (n = 6 each) compared with placebo (n = 6). Subjects who were randomized to receive 1 mg/mL concentrations were subsequently administered 5 mg/mL concentrations at least 2 weeks later, those given 2 mg/mL were crossed over to 4 mg/mL, and those in the 5-mg/mL group were crossed over to 1 mg/mL concentrations.

MAIN OUTCOME MEASURES

Subjects recorded intravenous infusion toleration using visual analog scales ranging from 0 (no signs or symptoms) to 10 (poor toleration) for erythema, pain, swelling, and tenderness. Vascular Doppler recordings were obtained during and after infusion cephalad to the infusion site.

RESULTS

Infusion site reactions increased in incidence and severity with infusion concentrations of 4 and 5 mg/mL; the most frequent reactions were tenderness and erythema. There were no apparent trends in Doppler readings.

CONCLUSIONS

Single doses of azithromycin 1 g at infusate concentrations up to 2 mg/mL were well tolerated when administered over 1 hour to healthy men.