Dosing & Uses
Dosage Forms & Strengths
injection, lyophilized powder for reconstitution
- 500mg/vial
tablet
- 250mg
- 500mg
oral suspension
- 100mg/5mL
- 200mg/5mL
Community-acquired Pneumonia
Indicated for treatment of community-acquired pneumonia due to Chlamydophila pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, or Streptococcus pneumoniae in patients appropriate for oral therapy
500 mg PO x 1 dose on Day 1, followed by 250 mg PO qDay on Days 2-5
Pharyngitis or Tonsillitis
Indicated for treatment of pharyngitis/tonsillitis caused by Streptococcus pyogenes as an alternative therapy in individuals who cannot use first-line therapy
500 mg PO x 1 dose on Day 1, followed by 250 mg PO qDay on Days 2-5
Uncomplicated skin/skin structure
Indicated for treatment of uncomplicated skin and skin structure infections due to Staphylococcus aureus, Streptococcus pyogenes, or Streptococcus agalactiae
500 mg PO x 1 dose on Day 1, followed by 250 mg PO qDay on Days 2-5
Acute bacterial exacerbations of chronic obstructive pulmonary disease
Indicated for treatment of acute bacterial exacerbations of chronic bronchitis due to Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae
500 mg PO qDay for 3 days OR
Alternatively, 500 mg PO x 1 dose on Day 1, followed by 250 mg PO qDay on Days 2-5
Acute bacterial sinusitis
Indicated for treatment of acute bacterial sinusitis due to Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae
500 mg PO qDay x 3 days
Genital Ulcer Disease (Chancroid)
Indicated for treatment of genital ulcer disease in men due to Haemophilus ducreyi (chancroid)
Efficacy in treatment of chancroid in women has not been established
1000 mg PO x 1 dose
Nongonococcal or Gonococcal Urethritis and Cervicitis
Indicated for treatment of urethritis and cervicitis due to Chlamydia trachomatis or Neisseria gonorrhoeae
1000 mg PO x 1 dose
Pelvic Inflammatory Disease
Indicated for treatment of pelvic inflammatory disease due to Chlamydia trachomatis, Neisseria gonorrhoeae, or Mycoplasma hominis in patients who require initial IV therapy
If anaerobic microorganisms are suspected of contributing to the infection, administer an antimicrobial agent with anaerobic activity in combination with azithromycin
Coronavirus Disease 2019 (COVID-19) (Off-label)
Data available as of March 25, 2020
Note: Limited data available; no drug is FDA approved to treat COVID-19
Azithromycin may be considered for use as part of an investigational protocol for patients with COVID-19
For more information, see the CDC website (link https://www.cdc.gov/coronavirus/2019-ncov/hcp/therapeutic-options.html)
Additional Medscape COVID-19 references are available
- Coronavirus Disease 2019 (COVID-19) (link https://emedicine.medscape.com/article/2500114-overview)
- Novel Coronavirus Resource Center (link https://www.medscape.com/resource/coronavirus)
Cat Scratch Disease (Off-label)
>45.5 kg: 500 mg PO once, then 250 mg once daily for 4 days
Pertussis (Off-label)
500 mg PO once, then 250 mg once daily for 4 days
Endocarditis (Off-label)
Prophylaxis
500 mg PO 30-60 min before procedure
Current American Heart Association (AHA) guidelines recommend only for high-risk patients
Dosing Considerations
Use only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria in order to reduce the development of drug-resistant bacteria and maintain the effectiveness of azithromycin
Limitations of use
-
Do not use in patients with pneumonia who may be inappropriate for oral therapy because of moderate to severe illness or risk factors such as any of the following:
- Patients with cystic fibrosis
- Patients with nosocomial infections
- Patients with known or suspected bacteremia
- Patients requiring hospitalization
- Elderly or debilitated patients
- Patients with significant underlying health problems that may compromise their ability to respond to their illness (including immunodeficiency or functional asplenia)
Dosage Forms & Strengths
injection, lyophilized powder for reconstitution
- 500mg/vial
tablet
- 250mg
- 500mg
oral suspension
- 100mg/5mL
- 200mg/5mL
Acute Otitis Media
Indicated for treatment of acute otitis media in patient >6 months of age caused by Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae
<6 months: Safety and efficacy not established
≥6 months
- 30 mg/kg PO x 1 dose OR
-
Alternative dosing
- 10 mg/kg PO qDay for 3 days OR
- 10 mg/kg PO x 1 dose on Day 1 followed by 5 mg/kg on Days 2-5
Community-acquired Pneumonia
<6 months: Safety and efficacy not established
≥6 months: 10 mg/kg PO x 1 dose on Day 1, followed by 5 mg/kg PO on Days 2-5
Pharyngitis/Tonsillitis
Indicated for treatment of pharyngitis/tonsillitis in patients >2 years of age caused by Streptococcus pyogenes as an alternative therapy in individuals who cannot use first-line therapy
<2 years: Safety and efficacy not established
≥2 years: 12 mg/kg PO qDay for 5 days; not to exceed 500 mg/day
Chlamydia Trachomatis Infection (Off-label)
Treatment of cervicitis or urethritis
Children and adolescents ≥45 kg: 1 g PO as single dose
Cat Scratch Disease (Off-label)
≤45 kg: 10 mg/kg (not to exceed 500 mg/dose) PO as single dose; then 5 mg/kg (not to exceed 250 mg/dose) PO qDay on days 2 through 5
>45 kg: 500 mg PO once, then 250 mg once daily for 4 days
Dosing Considerations
Use only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria in order to reduce the development of drug-resistant bacteria and maintain the effectiveness of azithromycin
Limitations of use
-
Do not use in patients with pneumonia who may be inappropriate for oral therapy because of moderate to severe illness or risk factors such as any of the following:
- Patients with cystic fibrosis
- Patients with nosocomial infections
- Patients with known or suspected bacteremia
- Patients requiring hospitalization
- Debilitated patients
- Patients with significant underlying health problems that may compromise their ability to respond to their illness (including immunodeficiency or functional asplenia)
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Adverse Effects
>10%
High single dose therapy
- Diarrhea (52.8%)
- Nausea (32.6%)
- Abdominal pain (27%)
- Loose stool (19.1%)
1-10%
Elevated ALT, AST, creatinine (4-6%)
Elevated LDH, bilirubin (1-3%)
Community-acquired pneumonia
- Pain at injection site (6.5%)
- Diarrhea (4.3%)
- Nausea (3.9%)
- Local inflammation (3.1%)
- Abdominal pain (2.7%)
- Vomiting (1.4%)
Pelvic inflammatory disease
- Diarrhea (8.5%)
- Nausea (6.6%)
- Vaginitis (2.8%)
- Abdominal pain (1.9%)
- Anorexia (1.9%)
- Rash and pruritus (1.9%)
<1%
Dyspepsia
Flatulence
Mucositis
Oral Moniliasis
Gastritis
Headache
Somnolence
Bronchospasm
Taste perversion
Leukopenia
Neutropenia
Decreased platelet count
Elevated serum alkaline phosphatase
Postmarketing Reports
Allergic: Arthralgia, edema, urticaria and angioedema
Cardiovascular: Arrhythmias (eg, ventricular tachycardia), hypotension, QT prolongation, and torsades de pointes
Gastrointestinal: Anorexia, constipation, dyspepsia, flatulence, vomiting/diarrhea, pseudomembranous colitis, pancreatitis, oral candidiasis, pyloric stenosis, and reports of tongue discoloration
General: Asthenia, paresthesia, fatigue, malaise and anaphylaxis (including fatalities).
Genitourinary: Interstitial nephritis and acute renal failure and vaginitis
Hematopoietic: Thrombocytopenia
Liver/biliary: Abnormal liver function, hepatitis, cholestatic jaundice, hepatic necrosis, and hepatic failure
Nervous system: Convulsions, dizziness/vertigo, headache, somnolence, hyperactivity, nervousness, agitation and syncope
Psychiatric: Aggressive reaction and anxiety
Skin/appendages: Pruritus, serious skin reactions including, erythema multiforme, AGEP, Stevens-Johnson syndrome, toxic epidermal necrolysis, and DRESS
Special senses: Hearing disturbances including hearing loss, deafness and/or tinnitus and reports of taste/smell perversion and/or loss
Warnings
Contraindications
Hypersensitivity to azithromycin, erythromycin, any macrolides or ketolides
History of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin
Cautions
Abnormal liver function, hepatitis, cholestatic jaundice, hepatic necrosis, and hepatic failure have been reported, some of which have resulted in death; discontinue treatment immediately if signs and symptoms of hepatitis occur
Infantile Hypertrophic Pyloric Stenosis (IHPS) has been reported; advise direct parents and caregivers if vomiting or irritability with feeding occurs
Clostridium difficile associated diarrhea (CDAD) has been reported, and may range in severity from mild diarrhea to fatal colitis; if CDAD is suspected or confirmed, discontinue ongoing antibacterial use not directed against C. difficile; institute appropriate fluid and electrolyte management, protein supplementation, antibacterial treatment of C. difficile, and surgical evaluation as clinically indicated
Exacerbations of symptoms of myasthenia gravis and new onset of myasthenic syndrome have been reported
Antibacterial agents used to treat nongonococcal urethritis may mask or delay the symptoms of incubating syphilis; all patients with sexually transmitted urethritis or cervicitis should have a serologic test for syphilis and appropriate testing for gonorrhea performed at the time of diagnosis; if infection confirmed, initiate appropriate antibacterial therapy and follow-up tests for these diseases
Local IV site reactions have been reported with IV azithromycin
Prescribing azithromycin in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria
QT prolongation
- Prolonged cardiac repolarization and QT interval, imparting a risk of developing cardiac arrhythmia and torsades de pointes, have been reported with macrolides, including azithromycin
- Elderly patients may be more susceptible to drug-associated effects on the QT interval
-
Consider the risk of QT prolongation for at-risk groups including:
- Patients with known prolongation of the QT interval, a history of torsades de pointes, congenital long QT syndrome, bradyarrhythmias or uncompensated heart failure
- Patients on drugs known to prolong the QT interval
- Patients with ongoing proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, and in patients receiving Class IA (quinidine, procainamide) or Class III (dofetilide, amiodarone, sotalol) antiarrhythmic agents
Hypersensitivity
- Serious allergic reactions, including angioedema, anaphylaxis, and dermatologic reactions including Acute Generalized Exanthematous Pustulosis (AGEP), Stevens Johnson syndrome, and toxic epidermal necrolysis have been reported
- Cases of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) have also been reported
- If an allergic reaction occurs, discontinue drug and institute appropriate therapy
- Be aware that allergic symptoms may reappear after symptomatic therapy has been discontinued
Drug interaction overview
- Coadministration of nelfinavir at steady-state with a single oral dose of azithromycin resulted in increased azithromycin serum concentrations; closely monitor for adverse reactions of azithromycin
- Spontaneous postmarketing reports suggest that coadministration of azithromycin may potentiate the effects of oral anticoagulants (eg, warfarin), although the prothrombin time was not affected in the dedicated drug interaction study with azithromycin and warfarin; carefully monitor prothrombin time while patients are receiving azithromycin and oral anticoagulants concomitantly
- Drug interactions with digoxin, colchicine or phenytoin have been observed when combined other macrolide; until further data are developed regarding drug interactions when digoxin, colchicine or phenytoin are used with azithromycin careful monitoring of patients is advised
Bronchiolitis obliterans
- August 3, 2018: FDA issues warning letter to healthcare providers
- Increased relapse and mortality observed with azithromycin in the clinical trial entitled ALLOZITHRO (evaluation of the efficacy of azithromycin to prevent bronchiolitis obliterans syndrome [BOS] after allogenic hematopoietic stem cell transplantation [HSCT])
- The study was terminated early after an increased risk of relapses was observed in patients taking azithromycin compared with placebo
- Azithromycin is not indicated for prophylaxis of bronchiolitis obliterans syndrome (BOS) in patients undergoing HSCT and should not be used off-label for this condition
Pregnancy & Lactation
Pregnancy
Available data on use in pregnant women have not identified any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes
Animal data
- Decreased viability and delayed development were observed in the offspring of pregnant rats administered azithromycin from day 6 of pregnancy through weaning at a dose equivalent to 4 times an adult human daily dose of 500 mg based on body surface area
Lactation
Present in human milk
Non-serious adverse reactions have been reported in breastfed infants after maternal administration of azithromycin
No data available on the effects of azithromycin on milk production
Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for azithromycin and any potential adverse effects on the breastfed infant from azithromycin or from the underlying maternal condition
Clinical considerations
Advise women to monitor the breastfed infant for diarrhea, vomiting, or rash
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Binds to 50S ribosomal subunit of susceptible microorganisms and blocks dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest; does not affect nucleic acid synthesis
Concentrates in phagocytes and fibroblasts, as demonstrated by in vitro incubation techniques; in vivo studies suggest that concentration in phagocytes may contribute to drug distribution to inflamed tissues
Absorption
Absolute bioavailability: 38% (250-mg capsules)
Peak plasma concentration
- Oral (3-day regimen): 0.44 mcg/mL (Day 1); 0.54 mcg/mL (Day 3)
- Oral (5-day regimen): 0.43 mcg/mL (Day 1); 0.24 mcg/mL (Day 5)
- IV: 1.14 mcg/mL (healthy volunteers); 3.63 mcg/mL (hospitalized patients)
AUC
- Oral (3-day regimen): 17.4 mcg⋅hr/mL
- Oral (5-day regimen): 154.9 mcg⋅hr/mL
- IV: 8.03 mcg⋅hr/mL (healthy volunteers); 9.6 mcg⋅hr/mL (hospitalized patients)
Effects of food
- Oral suspension: When administered with food, peak plasma concentration increased by 56% and AUC unchanged
- Tablets: No effect
Distribution
Protein bound: 51% (0.02 mcg/mL); 7% (2 mcg/mL)
Elimination
Clearance: 630 mL/min (single 500-mg oral and IV dose)
Half-life
- Oral (3-day regimen): 71.8 hr
- Oral (5-day regimen): 68.9 hr
Excretion
- IV, 1st dose: 11%
- IV, 5th dose: 14%
- Oral: 6% (unchanged)
- Biliary excretion is a major route of elimination for unchanged drug, following oral administration
Administration
IV Incompatibilities
Y-site: Amikacin, aztreonam, cefotaxime, ceftazidime, ceftriaxone, cefuroxime, ciprofloxacin, clindamycin, droperidol, famotidine, fentanyl, furosemide, gentamicin, imipenem, cilastatin, ketorolac, levofloxacin, morphine, piperacillin-tazobactam, ondansetron(?), potassium chloride, ticarcillin-clavulanate, tobramycin
Other IV substances, additives, or medications should not be added to azithromycin, or infused simultaneously through the same IV line
IV Compatibilities
0.9% NaCl
0.45% NaCl)
Dextrose 5% in Water (D5W)
Lactated Ringer Solution (LR)
D5W in 0.45% NaCl with 20 mEq KCl
D5W in LR
D5W in 0.3% NaCl
D5W in 0.45% NaCl
Normosol-M in D5W
Normosol-R in D5W
IV Preparation
Add 4.8 mL of sterile water for injection to 500-mg vial; final concentration is (100 mg/mL); shake vial until all of the drug is dissolved
Visually inspect vial for particulate matter before administration; discard if particular matter is present
Dilute reconstituted drug in either a 250-mL (final concentration 2 mg/mL) or 500-mL IV bag (final concentration 1 mg/mL)
IV Administration
1 mg/mL diluted solution: Infuse over 3 hr
2mg/mL diluted solution: Infuse over 1 hr
Oral Suspension Preparation
Final concentration after reconstitution is 100 mg/5 mL
- Add 9 mL of water to 300-mg bottle
Final concentration after reconstitution is 200 mg/5 mL
- Add 9 mL of water to 600-mg bottle
- Add 12 mL of water to 900-mg bottle
- Add 15 mL of water to 1200-mg bottle
Oral Administration
Tablets and oral suspension: Take with or without food
Oral suspension: Shake well before use; refer to prescribing information for dosing information
Storage
Unopened vial: Store at <30ºC (86ºF)
Reconstituted vial: Store at <30ºC (86ºF) for 24 hr
Diluted solutions: Store <30ºC (86ºF) for 24 hr OR refrigerate at 5ºC (41ºF)
Reconstituted oral suspension: Store at 5-30ºC (41-86ºF) and use within 10 days; discard after full dosing is completed
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Formulary
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