Comparison of the serum and intracellular pharmacokinetics of azithromycinin healthy and diabetic volunteers

Study Objective. To compare serum and intracellular pharmacokinetics of azi thromycin 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 fol lowed 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 intrac ellular measurement of azithromycin. Measurements and Main Results. Pharmacokinetic parameters were calculated b y noncompartmental methods and compared with a t test. The groups did not d iffer in maximum concentration, time to maximum concentration, or area unde r 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 w as slightly lower in patients.