Study objective: To compare serum and intracellular pharmacokinetics of azithromycin in healthy volunteers and patients with diabetes.
Design: Open-label, parallel study.
Setting: Clinical research center.
Subjects: Twelve patients with diabetes and 12 healthy volunteers.
Interventions: Subjects were given a single 500-mg dose of azithromycin followed by 250 mg/day for 2 days. Blood samples were obtained just before and after the third dose for up to 24 hours for serum and 168 hours for intracellular measurement of azithromycin.
Measurements and main results: Pharmacokinetic parameters were calculated by noncompartmental methods and compared with a t test. The groups did not differ in maximum concentration, time to maximum concentration, or area under the concentration-time curve in serum or polymorphonuclear cells (PMNs). Differences in the PMN:serum ratio were observed at the 24-hour time point (healthy 1209 +/- 432, diabetic 859 +/- 286, p=0.051).
Conclusion: In general, the pharmacokinetics of azithromycin are comparable in diabetics and healthy volunteers. Accumulation of drug in macrophages was slightly lower in patients.