Azithromycin, the active component of Zithromax, boasts excellent oral bioavailability, reaching peak plasma concentrations within 2-3 hours of ingestion. Absorption isn’t significantly affected by food.
Distribution is extensive, penetrating various tissues and fluids, including the lungs, skin, and prostate. High concentrations accumulate in phagocytic cells, contributing to its efficacy against intracellular pathogens. Azithromycin binds moderately to plasma proteins (approximately 50%).
Azithromycin undergoes hepatic metabolism, primarily through cytochrome P450 enzymes. However, a significant portion (50%) is excreted unchanged in the urine, primarily through glomerular filtration, within the first 24 hours. The remaining portion is eliminated via bile. The elimination half-life is prolonged, ranging from 2 to 4 days, accounting for its once-daily dosing regimen.
Important considerations: Renal or hepatic impairment may affect elimination, potentially necessitating dose adjustments. Drug interactions can occur due to competition for hepatic metabolism; careful monitoring is advised when co-administering azithromycin with other medications metabolized by the cytochrome P450 system.
Note: This information provides a general overview. Always consult the official prescribing information for detailed pharmacokinetic parameters and specific recommendations for patient care.
