Clarithromycin Dosage in Renal Impairment
For adults with severe renal impairment (creatinine clearance <30 mL/min), reduce the clarithromycin dose by 50%. 1
Standard Dosing for Adults with Normal Renal Function
- The FDA-approved dosage for clarithromycin extended-release tablets is 1 gram once daily for 7-14 days, depending on the infection type 1
- For immediate-release formulations, the standard adult dose is 500 mg twice daily 2, 3
- The extended-release formulation must be taken with food and swallowed whole—never crushed, chewed, or broken 1
Renal Impairment Dosing Adjustments
The National Kidney Foundation recommends reducing clarithromycin dose by 50% in patients with severe renal impairment (CrCl <30 mL/min). 2 This is reinforced by FDA labeling, which specifies:
- Severe renal impairment (CrCl <30 mL/min): Reduce dose by 50% 1
- Moderate renal impairment (CrCl 30-60 mL/min) with concomitant ritonavir or atazanavir: Reduce dose by 50% 1
- Severe renal impairment (CrCl <30 mL/min) with concomitant ritonavir or atazanavir: Reduce dose by 75% 1
The pharmacokinetic rationale for these adjustments is that clarithromycin undergoes primarily renal clearance (6.7-12.8 L/h), and severe renal impairment causes increased plasma concentrations and prolonged elimination half-life for both clarithromycin and its active metabolite, 14-hydroxyclarithromycin 4.
Additional Considerations for Renal Patients
- When clarithromycin is used with ritonavir or lopinavir-ritonavir in patients with CrCl <60 mL/min, reduce the dose by 50%; if CrCl <30 mL/min, reduce by 75% 2
- The active metabolite 14-hydroxyclarithromycin also accumulates in renal impairment, contributing to both efficacy and potential toxicity 4
- Dosage adjustments should be considered when creatinine clearance falls below 1.8 L/h (30 mL/min) 4
Monitoring in Renal Impairment
- Monitor for gastrointestinal adverse effects (nausea, vomiting, abdominal pain, metallic taste), which occur in 9-11% of patients and may be more pronounced with higher drug levels 5
- Periodic liver function tests are recommended, especially in the first 3 months of therapy 5
- Watch for QT prolongation, particularly in elderly patients or those on other QT-prolonging medications 5
Common Pitfalls to Avoid
- Do not use standard doses in severe renal impairment—this significantly increases the risk of adverse effects due to drug accumulation 1, 4
- Do not forget to adjust for drug interactions—protease inhibitors like ritonavir and atazanavir require additional dose reductions beyond those for renal impairment alone 1
- Do not use extended-release formulations on an empty stomach—bioavailability decreases by 30% when taken without food 6
- Do not crush or break extended-release tablets—this destroys the controlled-release mechanism and can lead to dose dumping 1