[Clinical pharmacokinetics of azithromycin]

Area of Science:

• Pharmacology
• Drug Metabolism
• Clinical Pharmacokinetics

Context:

• Azithromycin is a widely used macrolide antibiotic.
• Understanding its pharmacokinetic profile is crucial for optimizing therapeutic efficacy.
• Food interactions can significantly impact oral drug absorption.

Purpose:

• To characterize the pharmacokinetic properties of azithromycin following oral administration.
• To investigate the influence of food on azithromycin bioavailability.
• To determine the elimination pathways and half-life of azithromycin.

Summary:

• Oral azithromycin bioavailability is approximately 37%, with a 50% reduction when administered with food.
• Peak plasma concentrations are achieved within 2 hours, followed by extensive tissue distribution.
• Elimination occurs mainly unchanged in feces via biliary excretion; urinary excretion is minimal.
• The mean terminal elimination half-life is 2 to 4 days.
• Pharmacokinetics remain largely unchanged in elderly individuals and those with mild to moderate renal or hepatic impairment.

Impact:

• Provides essential data for appropriate dosing strategies to maximize therapeutic outcomes.
• Highlights the importance of administration timing relative to meals for consistent drug levels.
• Informs clinical practice regarding azithromycin use in specific patient populations.
• Contributes to the understanding of macrolide antibiotic disposition in the human body.