Azithromycin

C. diff Risk

Medium

Oral Bioavailability

Moderate

Approximate Cost

IV-$9/d PO-$1/d

Dosing

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.

Prolonged half life may contribute to macrolide resistance

Major Interactions

Other drugs that prolong QTc

Increases cyclosporine levels

May increase digoxin levels

Statins increased risk of rhabdomyolysis

Additional Information

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

Pharmacology

Antimicrobial class: Macrolide

Pregnancy category: B

Average serum half life: 68.0

Biliary penetration: Therapeutic

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Poor