C. diff Risk


Oral Bioavailability

Low (20 to 40%)

Approximate Cost

$0.24/day (PO)
$5.75/day (IV)

Spectrum Of Activity


Respiratory Infection
500mg PO/IV on day 1 then 250mg daily for 4 days

General Information

Common Usage

  • Community acquired pneumonia

  • Pertussis

  • Upper respiratory tract infections

  • Chlamidial infections

  • Mycobacterial infections

  • Mycobacterium avium complex (MAC) prophylaxis in HIV patients

Drug Monitoring

Monitor QTc in patients with increased risk

Adverse Effects

Prolongation of QTc interval. Association with increased cardiovascular mortality in observational studies.

Major Interactions

  • Other drugs that prolong QTc

  • Increases cyclosporine levels

  • May increase digoxin levels

  • Statins increased risk of rhabdomyolysis

Tablet/Capsule Strengths

No prescribing restrictions

Additional Information

IV Administration

  • Dilute in 250-500 mL of D5W or NS.

  • Infuse over 60 minutes.

EH Prescribing Restrictions

Community IV Formulary (St. John’s Metro)

Tablets can be crushed and given via NG route; Liquid also available


Antimicrobial class: Macrolide

Pregnancy category: B

Average serum half life: 68 hours

Biliary penetration: Therapeutic

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Poor