Clarithromycin

C difficile risk
Medium
Oral Bioavailability
Excellent

Spectrum Of Activity

Dosing

15 mg/kg/DAY divided q12h. Max: 500mg/dose.

15 to 30 mg/kg/DAY divided q12h. Max: 500mg/dose.

Adjustment not needed as long as renal function is normal

Renally cleared, requires dosage adjustment with changes in renal function. Consult a pharmacist for renal dosing.

General Information

CAP, Pertussis, URTI, H. pylori, and mycobacterial infections

Monitor QTc in patients with increased risk

  • GI upset, diarrhea

  • Rash

  • Prolongation of QTc interval

  • Substrate of CYP3A4.

  • Multiple CYP450 interactions possible - consult a pharmacist for more detail. May increase digoxin, carbamazepine level. Use caution with QTc prolonging medications.

Antimicrobial class: Macrolide

Average serum half life:

Adult:

  • Clarithromycin: 3-7 hours

  • 14-OH-clarithromycin (active metabolite): 5-9 hours

Route of Elimination: Urine (20-40% as unchanged drug, additional 10%-15% as active metabolite); feces (29% to 40% mostly as metabolites)