Adults

Typical adult dose is 250-500 mg twice daily for 7-14 days, depending on the infection. For H. pylori eradication, 500 mg twice daily as part of a triple therapy regimen.

Elderly

No specific dose adjustment required unless severe renal impairment is present.

Renal_impairment

For creatinine clearance < 30 mL/min, the dose should be halved or dosing interval extended. Max dose 250 mg twice daily or 500 mg once daily.

Onset

Onset of action within 2 hours.

Excretion

Approximately 20-40% excreted renally as parent drug and metabolite; remainder eliminated through bile/feces.

Half life

Parent drug: 3-7 hours (dose-dependent), Active metabolite (14-hydroxyclarithromycin): 5-9 hours.

Absorption

Rapidly absorbed from the gastrointestinal tract, bioavailability is about 50-55%.

Metabolism

Extensively metabolized in the liver via CYP3A4, forming an active metabolite, 14-hydroxyclarithromycin.

Digoxin

Increased digoxin levels; monitor digoxin serum levels.

Warfarin

Increased anticoagulant effect, leading to bleeding risk; monitor INR closely.

Colchicine

Increased colchicine toxicity, especially in renal/hepatic impairment; avoid co-administration.

Simvastatin/Lovastatin

Increased risk of myopathy/rhabdomyolysis due to CYP3A4 inhibition; avoid co-administration or use lower doses of statins under careful monitoring.