What is the dose of clarithromycin?

Clarithromycin Injectable Dosing

Clarithromycin is not available in an injectable formulation—it is only available as oral tablets and oral suspension. 1

Available Formulations

• Clarithromycin is supplied as immediate-release tablets (250 mg and 500 mg), extended-release tablets (500 mg), and oral suspension granules 1
• All clarithromycin formulations must be administered orally 1

Standard Oral Dosing for Adults

For most respiratory tract infections in adults, the recommended dose is 500 mg twice daily (immediate-release) or 1000 mg once daily (extended-release) for 7-14 days, depending on the infection. 2, 1

Infection-Specific Dosing:

• Acute bacterial exacerbation of chronic bronchitis: 1 gram extended-release once daily for 7 days, or 500 mg immediate-release twice daily 1
• Community-acquired pneumonia: 1 gram extended-release once daily for 7 days, or 500 mg immediate-release twice daily 1
• Acute maxillary sinusitis: 1 gram extended-release once daily for 14 days 1
• Pertussis: 1 gram per day in two divided doses (500 mg twice daily) for 7 days 3, 2
• Mycobacterium avium complex: 500 mg twice daily with ethambutol, continued long-term 3, 2

Pediatric Oral Dosing

• Children >1 month: 15 mg/kg/day divided into 2 doses (maximum 1 g/day) for 7 days 3, 2
• Infants <1 month: Clarithromycin is contraindicated due to unknown risk of infantile hypertrophic pyloric stenosis 3

Dose Adjustments

Renal Impairment:

• Severe renal impairment (CrCl <30 mL/min): Reduce dose by 50% 1
• Moderate renal impairment (CrCl 30-60 mL/min) with concomitant atazanavir or ritonavir: Reduce dose by 50% 1
• Severe renal impairment with concomitant atazanavir or ritonavir: Reduce dose by 75% 1

Low Body Weight or Elderly:

• Patients <50 kg or >70 years: Consider reducing to 250 mg twice daily or 500 mg once daily due to gastrointestinal intolerance 3

Critical Administration Instructions

• Extended-release tablets must be taken with food to maximize bioavailability (30% reduction if taken fasting) 1, 4
• Extended-release tablets must be swallowed whole—do not chew, break, or crush 1
• Immediate-release formulations can be taken with or without food 5, 6

Common Adverse Effects

• Gastrointestinal symptoms are most common: metallic taste, nausea, vomiting, diarrhea, and abdominal pain 3, 2
• Clarithromycin toxicity is dose and serum-level related—most adults cannot tolerate more than 1000 mg/day 3

Critical Drug Interactions

• Contraindicated with: cisapride, pimozide, astemizole, terfenadine (risk of fatal cardiac arrhythmias) 3, 2, 1
• Contraindicated with: lomitapide, lovastatin, simvastatin (risk of rhabdomyolysis) 1
• Contraindicated with colchicine in patients with renal or hepatic impairment 1
• Clarithromycin inhibits CYP3A4, leading to multiple potential drug interactions with medications metabolized by this pathway 3, 2, 5

Monitoring Recommendations

• ECG monitoring: Baseline and at 2 weeks for patients at risk of QT prolongation 2
• Audiometry: Baseline and if hearing loss symptoms develop 2
• Laboratory monitoring: Complete blood count, renal function, and liver function tests periodically during treatment 2