Clarithromycin

Class: Macrolide Antibiotic

Mechanism: Inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit.

Dosage

• Children: 7.5 mg/kg/dose every 12 hours (Max: 500 mg per dose)
• Adults: 250–500 mg every 12 hours

Maximum Dose

1 g/day in divided doses

Side Effects

• GI upset (nausea, vomiting, diarrhea, abdominal pain)
• Taste disturbances (metallic taste)
• Headache
• QT prolongation
• Hepatotoxicity (rare)

Contraindications

• Known hypersensitivity to macrolides
• History of cholestatic jaundice/hepatic dysfunction with clarithromycin
• Concomitant use with drugs metabolized by CYP3A4 that may cause QT prolongation (e.g., cisapride, pimozide)

Compatible Solvent

Oral suspension: Reconstitute with sterile water.
IV form is not available (unlike azithromycin).

Special Precautions

• Use with caution in hepatic impairment
• Adjust dose in renal impairment (CrCl < 30 mL/min: reduce dose by 50%)
• Monitor QT interval in patients with cardiac disease
• Significant drug interactions due to CYP3A4 inhibition