Antimicrobials
Azithromycin

Azithromycin

Medium
Moderate
See below under General Info

Spectrum of Activity

Dosing

General Information

Hospital Formulary Status Yes (PO solid, PO susp, parenteral inj)

In-Hospital Cost will be updated

PharmaCare Formulary Status Yes (PO solid, PO susp)

SA None

PharmaCare Coverage 250mg PO - $1.0163/tab 100mg/5ml PO susp recon - $0.4024/ml 200mg/5ml PO susp recon - $0.5702/ml

Outpatient Cost 250mg PO - $1.14-2.68/tab 600mg PO - $11.83-13.64/tab 100mg/5ml PO susp recon - $0.40-0.44/ml 200mg/5ml PO susp recon - $0.57-0.63/ml 500mg powder for soln/inj - $15.73-17.30/vial

  • Community acquired pneumonia
  • Pertussis
  • Upper respiratory tract infections
  • Chlamydial infections
  • Mycobacterial infections
  • Mycobacterium avium complex (MAC) prophylaxis in HIV patients

Monitor QTc in patients with increased risk

Gastritis (PO and IV)

  • sx: nausea, vomiting, diarrhea, abdominal pain and cramping with subsequent loose stools
  • abdominal cramping caused by stimulation of motilin receptors
  • dysgeusia is common with clarithromycin but rare with azithromycin
  • azithromycin and clarithromycin are better tolerated than erythromycin
  • intolerance to one macrolide does not predict intolerance to another

Hepatotoxicity (mainly with IV)

  • includes abnormal liver function tests, hepatitis, cholestatic jaundice, hepatic necrosis, hepatic failure and death
  • contraindicated in patients with history of cholestatic jaundice or hepatic dysfunction from azithromycin use
  • should be discontinued immediately if signs or symptoms of hepatitis occur

QT interval prolongation and CV mortality (PO and IV)

  • associated with increased CV and all-cause mortality
  • can occur with a 5-day course
  • assess if patient is at risk for torsades de pointes (history of long QT interval, taking other QT-prolonging drugs, drug interactions, older age, electrolyte abnormalities)

Hearing loss (mainly with IV)

  • can be reversible or irreversible
  • especially at high doses

Severe reactions (PO and IV)

  • includes SJS, drug reaction with eosinophilia and systemic symptoms (DRESS), pseudomembranous colitis and exacerbations of myasthenia gravis
  • may exacerbate muscle weakness in persons with myasthenia gravis
  • may persist for several days due to its long half-life (azithromycin)

Cancer relapse and death (mainly with IV)

  • increased risk in hematopoietic stem cell transplant recipients with acute lymphoblastic leukemia, acute myeloid leukemia or myelodysplastic syndrome or for prevention of bronchiolitis obliterans
  • can occur with long-term (2 years) use
  • avoid long-term prophylactic azithromycin in patients with blood or lymph node cancers
  • no increased risk for treatment of established moderate to severe chronic graft-versus-host disease
  • Other drugs that prolong QTc
  • Increase INR with warfarin
  • Increases cyclosporine levels
  • May increase digoxin levels
  • Increased risk of rhabdomyolysis with statins

Antimicrobial class: Macrolide

Pregnancy category: B

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

Average serum half life: 68.0 hr

Biliary penetration: Therapeutic

CSF penetration: Poor

Lung penetration: Therapeutic

Urine penetration: Poor