From the FDA Drug Label
Special PopulationsRenal Insufficiency Azithromycin pharmacokinetics were investigated in 42 adults (21 to 85 years of age) with varying degrees of renal impairment. Following the oral administration of a single 1,000 mg dose of azithromycin, mean Cmax and AUC0-120 increased by 5.1% and 4. 2%, respectively in subjects with mild to moderate renal impairment (GFR 10 to 80 mL/min) compared to subjects with normal renal function (GFR >80 mL/min).
The recommended dose of azithromycin for a 75-year-old female patient with Chronic Kidney Disease (CKD) stage 3 is not explicitly stated in the drug label. However, based on the information provided, for patients with mild to moderate renal impairment (GFR 10 to 80 mL/min), the mean Cmax and AUC0-120 increased by 5.1% and 4.2%, respectively, compared to subjects with normal renal function.
- No specific dosage adjustment is mentioned for patients with CKD stage 3.
- Caution should be exercised when administering azithromycin to patients with renal impairment.
- The drug label does not provide a clear recommendation for dosing in patients with CKD stage 3, and therefore, no conclusion can be drawn regarding the exact dose for this patient population 1.
From the Research
For a 75-year-old female patient with CKD stage 3, the recommended dose of azithromycin (Zithromax) is typically the standard adult dose of 500 mg on day 1, followed by 250 mg once daily for days 2-5 for most infections. No specific dose adjustment is required for CKD stage 3 (GFR 30-59 mL/min) as azithromycin is primarily eliminated through biliary excretion rather than renal clearance, as supported by studies such as 2 and 3. However, careful monitoring is advised due to the patient's advanced age and kidney impairment. Potential drug interactions should be assessed, particularly with medications that prolong QT interval, as azithromycin can rarely cause cardiac arrhythmias. Common side effects include gastrointestinal disturbances like nausea, diarrhea, and abdominal pain. The medication should be taken at least 1 hour before or 2 hours after meals for optimal absorption, though it can be taken with food if stomach upset occurs. If the infection is severe or involves resistant organisms, consultation with an infectious disease specialist may be warranted to determine if a different antibiotic regimen would be more appropriate. It's also important to consider other factors such as the type of infection being treated and the patient's overall health status, as discussed in studies like 4, 5, and 6. In general, azithromycin is a well-tolerated and effective antibiotic, but its use should be guided by evidence-based recommendations and careful consideration of individual patient factors.