II. Indications
- Activity Spectrum
- Spectrum includes organisms covered by Erythromycin
 - Increasing Macrolide resistance for most indications
 - Haemophilus Influenzae
 - Moraxella catarrhalis
 - Toxoplasmosis gondii
 - Mycobacterium Avium Complex (Clarithromycin better)
 - Borrelia Burgdorferi
 
 - Conditions
- Single dose Chlamydia Trachomatis treatment
 - Non-tuberculous Mycobacterial infections
 - Helicobacter infections
 - Community Acquired Pneumonia
- Limit to suspected Mycoplasma pneumonia or Legionella pneumonia
 - Macrolide resistant Pneumococcus is common
 - Consider Doxycycline as alternative
 
 - Streptococcal Pharyngitis (second line agent)
- Macrolides are only indicated in significant allergy to beta-lactams
 
 - Original indications that have fallen out of favor due to Antibiotic Resistance
- Otitis Media
- Not recommended due to increased resistance rates
 
 - Acute Sinusitis
- Not recommended due to growing resistance rates
 
 
 - Otitis Media
 
 - References
- (2013) Presc Lett 20(8): 44
 
 
III. Medications
- Intravenous
 - Tablets: 250, 500, 600 mg
 - Oral suspension: 100 ro 200 mg per 5 ml
- Take on an empty Stomach
 
 - Packs
- Z-Pak: 500 mg day 1, 250 mg days 2 to 5
 - Tri-Pak: 500 mg tabs x3
 - Packet containing 1000 mg
 
 
IV. Dosing
- See Pertussis
 - See Chlamydia Trachomatis
 - Take more than 1 hour before or 2 hours after food
 - 
                          General Dosing
- Adult
- Day 1: 500 mg orally daily
 - Day 2 to 5: 250 mg orally daily
 
 - Child
- Day 1: 10 mg/kg orally daily (maximum: 500 mg)
 - Day 2 to 5: 5 mg/kg orally daily (maximum: 250 mg)
 
 - Infant under age 6 months
- 10 mg/kg/day for 5 days
 
 
 - Adult
 - 
                          Group A Streptococcal Pharyngitis (second line agent in Beta Lactam allergy)
- Take 12 mg/kg up to 500 mg orally daily for 5 days
 
 - 
                          Acute Exacerbation of Chronic Bronchitis
                          
- Adult: Take 500 mg orally daily for 3 days
 
 - 
                          Chlamydia, Chancroid or Nongonococcal Urethritis
- Adult: Take 1 gram orally once
 - Doxycycline for 7 days is preferred
 
 - 
                          Mycobacterium Avium Complex Disease (e.g. AIDS)
- Adult: Take 1200 mg orally once weekly
 - Active disease is treated with at least 2 drugs
 
 
V. Pharmacokinetics
- Half Life: 68 hours
 
VI. Adverse Effects
- See Macrolide
 - 
                          Hypertrophic Pyloric Stenosis
                          
- Infants age <45 days
 
 - 
                          QT Prolongation with Azithromycin
- Class effect with Macrolides
 - Three fold increased risk of Sudden Cardiac Death while on Azithromycin
 - Higher risk with known QTc Prolongation, Hypokalemia, Hypomagnesemia, Class IA or III Antiarrhythmics
 - Ray (2013) N Engl J Med 366(20): 1881-90 [PubMed]
 
 
VII. Safety
- Considered safe in Lactation
 - Pregnancy Category C
- Macrolides in general (including Azithromycin) may increase heart defects with first trimester exposure of 5-7 days
 - Previously only Clarithromycin was considered a potential Teratogen (Cleft Lip association)
 - Fan (2020) BMJ 368: m331 +PMID:32075790 [PubMed]
 
 
VIII. Drug Interactions
- 
                          Drug-Induced QTc Prolongation
                          
- Avoid combining with other agents that prolong QTc
 
 - 
                          Warfarin
                          
- May increase INR
 
 - Aluminum or MagnesiumAntacids
- May interfere with Azithromycin absorption
 
 
IX. Resources
- Azithromycin Tablet (DailyMed)
 
Images: Related links to external sites (from Bing)
Related Studies
| azithromycin (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| AZITHROMYCIN 1 GM PWD PACKET | Generic | $19.97 each | 
| AZITHROMYCIN 100 MG/5 ML SUSP | Generic | $0.48 per ml | 
| AZITHROMYCIN 200 MG/5 ML SUSP | Generic | $0.41 per ml | 
| AZITHROMYCIN 250 MG TABLET | Generic | $0.33 each | 
| AZITHROMYCIN 500 MG TABLET | Generic | $0.64 each | 
| AZITHROMYCIN 600 MG TABLET | Generic | $1.29 each | 
| zithromax (on 2/23/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| ZITHROMAX 250 MG TABLET | Generic | $0.33 each | 
| ZITHROMAX 250 MG Z-PAK TABLET | Generic | $0.33 each |