C. diff Risk


Oral Bioavailability


Approximate Cost

Spectrum Of Activity


Respiratory Infection(not-hospitalized)
500mg PO/IV on day 1 then 250mg daily x 4 days

Respiratory Infection(hospitalized)
500 mg PO/IV daily x 5 days

non-respiratory infection
500mg PO/IV daily

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


  • Peridoc LFTs with prolonged use


  • Monitor QTc in patients with increased risk

  • GI side effects

Adverse Effects

  • GI effects

  • Allergic reaction

  • 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

  • Use with Statins increases risk of rhabdomyolysis

Additional Information

Very high tissue penetration and concentration intracellularly means in vivo activity may not be predicted by in vitro testing - e.g. Salmonella species.


Antimicrobial class: Macrolide

Pregnancy category: B

Average serum half life: 68 hours

Biliary penetration: Therapeutic

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Poor