Drug intolerance to high-dose clarithromycin among elderly patients

Area of Science:

• Pulmonology
• Infectious Diseases
• Clinical Pharmacology

Background:

• Chronic mycobacterial lung disease (CMLD) affects elderly patients, often with comorbidities.
• Clarithromycin is a macrolide antibiotic used in CMLD treatment.
• High-dose clarithromycin monotherapy poses potential risks in elderly populations.

Purpose of the Study:

• To evaluate the safety and tolerability of high-dose clarithromycin (1000 mg b.i.d.) monotherapy in elderly patients with CMLD.
• To assess adverse events, drug levels, and treatment discontinuation rates.
• To inform future dosing strategies for clarithromycin in this demographic.

Main Methods:

• Prospective study of 13 elderly patients (mean age 70) with CMLD.
• Treatment with clarithromycin 1000 mg twice daily (b.i.d.) as monotherapy.
• Monitoring of adverse events, liver enzymes, and serum drug levels (clarithromycin and 14-OH metabolite).

Main Results:

• 100% of patients experienced adverse events, most commonly bitter taste (92%) and nausea (92%).
• Five patients (38%) developed elevated liver enzymes.
• 85% of patients discontinued high-dose therapy within 3 months due to side effects, with higher drug levels correlating with discontinuation.

Conclusions:

• High-dose clarithromycin (1000 mg b.i.d.) monotherapy is poorly tolerated in elderly patients with CMLD.
• Adverse events and elevated drug levels necessitate dose reduction and careful monitoring.
• Future research should investigate lower clarithromycin doses, considering patient body mass and renal function.