Azithromycin – Uses, Dosage, Side Effects, Interactions

xxxxxxxrx hot sexy lady pic

Azithromycin is a semi-synthetic macrolide antibiotic structurally derived from erythromycin, and a member of a subclass of macrolide antibiotics with bacteriocidal and bacteriostatic activities. It has been used in the treatment of Mycobacterium avium intracellular infections, toxoplasmosis, and cryptosporidiosis. Azithromycin reversibly binds to the 50S ribosomal subunit of the 70S ribosome of sensitive microorganisms, thereby inhibiting the translocation step of protein synthesis, wherein a newly synthesized peptidyl tRNA molecule moves from the acceptor site on the ribosome to the peptidyl (donor) site, and consequently inhibiting RNA-dependent protein synthesis leading to cell growth inhibition and cell death. Azithromycin is an antibiotic useful for the treatment of a number of bacterial infections. This includes middle ear infections, strep throat, pneumonia, traveler’s diarrhea, and certain other intestinal infections. It may also be used for a number of sexually transmitted infections including chlamydia and gonorrhea infections.

Mechanism of Action of Azithromycin

Azithromycin binds to the 50S subunit of the 70S bacterial ribosomes and therefore inhibits RNA-dependent protein synthesis in bacterial cells.
Azithromycin usually is bacteriostatic, although the drug may be bactericidal in high concentrations against selected organisms. Bactericidal activity has been observed in vitro against Streptococcus pyogenes, S. pneumoniae, and Haemophilus influenzae. Azithromycin inhibits protein synthesis in susceptible organisms by penetrating the cell wall and binding to 50S ribosomal subunits, thereby inhibiting translocation of aminoacyl transfer-RNA and inhibiting polypeptide synthesis. The site of action of azithromycin appears to be the same as that of the macrolides (i.e., erythromycinclarithromycin), clindamycin, lincomycin, and chloramphenicol. The antimicrobial activity of azithromycin is reduced at low pH. Azithromycin concentrates in phagocytes, including polymorphonuclear leukocytes, monocytes, macrophages, and fibroblasts. Penetration of the drug into phagocytic cells is necessary for activity against intracellular pathogens (e.g., Staphylococcus aureus, Legionella pneumophila, Chlamydia trachomatis, Salmonella typhi).

Indications of Azithromycin

  • Acute bacterial sinusitis (adequately diagnosed)
  • Acute bacterial otitis media (adequately diagnosed)
  • Pharyngitis, tonsillitis
  • Acute exacerbation of chronic bronchitis (adequately diagnosed)
  • Mild to moderately severe community-acquired pneumonia
  • Skin and soft tissue infections
  • Uncomplicated Chlamydia trachomatis urethritis and cervicitis
  • Legionella Pneumonia
  • Mycoplasma Pneumonia
  • Pneumonia
  • Tonsillitis/Pharyngitis
  • Sinusitis
  • Skin and Structure Infection
  • Gonococcal Infection – Uncomplicated
  • Nongonococcal Urethritis
  • Chlamydia Infection
  • Cervicitis
  • Chancroid
  • Pelvic Inflammatory Disease
  • Chronic Obstructive Pulmonary Disease
  • Bronchitis
  • Mycobacterium avium-intracellular
  • Granuloma Inguinale
  • STD Prophylaxis
  • Pertussis Prophylaxis
  • Pertussis
  • Lyme Disease – Erythema Chronicum Migrans
  • Babesiosis
  • Bacterial Endocarditis Prophylaxis
  • Toxoplasmosis
  • Campylobacter Gastroenteritis
  • Upper Respiratory Tract Infection

Contraindication of Azithromycin

  • History of severe hypersensitivity (e.g. anaphylactic reaction) to any other type of betalactam antibacterial agent (penicillins, monobactams and carbapenems).
  • Hemolytic anemia
  • Liver problems
  • Interstitial nephritis
  • Subacute cutaneous lupus erythematosus
  • Systemic lupus erythematosus
  • Allergies macl& betalactams
  • Known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide antibiotic. Coadministration w/ pimozide. History of cholestatic jaundice/hepatic dysfunction associated w/ prior use of azithromycin.

Dosage of Azithromycin

Strengths: 250 mg, 500 mg, 600 mg; 1 g; 2 g; 2.5 g I.V; 100 mg/5 mL; 200 mg/5 mL Suspension

Chronic Obstructive Pulmonary Disease

Immediate-release

  • 500 mg orally once a day for 3 days OR 500 mg orally as a single dose on day 1, followed by 250 mg orally once a day on days 2 to 5

Pneumonia

Immediate-release

  • 500 mg orally as a single dose on day 1, followed by 250 mg orally once a day on days 2 to 5

Extended-release

  • 2 g orally once as a single dose
  • Parenteral: 500 mg IV once a day as a single dose for at least 2 days, followed by 500 mg (immediate-release formulation) orally to complete a 7- to 10-day course of therapy

Upper Respiratory Tract Infection

ASBMT and IDSA Recommendations

Bacterial infections within the first 100 days of HCT

Immediate-release

  • Alternative treatment: 250 mg orally once a day
  • Prevention of bacterial infections for HCT patients with anticipated neutropenic periods of at least 7 days

Tonsillitis/Pharyngitis

Immediate-release

  • 500 mg orally as a single dose on day 1, followed by 250 mg orally once a day on days 2 to 5

IDSA Recommendations
Immediate-release

  • Individuals with penicillin allergy: 12 mg/kg orally once a day
  • Maximum dose: 500 mg/day
  • Duration of therapy: 5 days

 Skin and Structure Infection

Immediate-release

  • 500 mg orally as a single dose on day 1, followed by 250 mg orally once a day on days 2 to 5

IDSA and NIH Recommendations
Immediate-release

  • Patients greater than 45 kg: 500 mg orally on day 1, then 250 mg orally once a day on days 2 through 5
  • Patients less than 45 kg: 10 mg/kg orally on day 1, then 5 mg/kg orally once a day for 4 additional days
  • Alternative therapy for Bartonella infections (not endocarditis or central nervous system infections): 500 mg orally once a day for at least 3 months

Community-acquired pneumonia

Immediate-release

  • 500 mg orally as a single dose on day 1, followed by 250 mg orally once a day on days 2 to 5

Extended-release

  • 2 g orally once as a single dose
  • Parenteral: 500 mg IV once a day as a single dose for at least 2 days, followed by 500 mg (immediate-release formulation) orally to complete a 7- to 10-day course of therapy

Sinusitis

Immediate-release

  • 500 mg orally once a day for 3 days

Extended-release

  • 2 g orally once as a single dose

Pelvic Inflammatory Disease

  • 500 mg IV once a day for 1 or 2 days, followed by 250 mg (immediate-release formulation) orally once a day to complete a 7-day course of therapy.

Pediatric Pneumonia

6 months and older

Immediate-release

  • 10 mg/kg (maximum: 500 mg/dose) orally on day 1, followed by 5 mg/kg (250 mg/dose) orally once a day on days 2 to 5

Extended-release

  • Patients less than 34 kg: 60 mg/kg (maximum dose: 2 g/dose) orally as a single dose
  • Patients 34 kg or greater: 2 g orally as a single dose

16 years and older

  • Parenteral: 500 mg IV once a day as a single dose for at least 2 days, followed by 500 mg (immediate-release formulation) orally to complete a 7- to 10-day course of therapy

IDSA and Pediatric Infectious Disease Society (PIDS) Recommendations

3 months to less than 5 years

  • Parenteral: 10 mg/kg on days 1 and 2 of treatment, transitioning to oral treatment when possible
  • Oral: 10 mg/kg orally on day 1, then 5 mg/kg/day orally once a day on days 2 to 5

5 years and older

  • Oral: 10 mg/kg (maximum: 500 mg/day) orally on day 1, followed by 5 mg/kg/day
  • maximum: 250 mg/day orally on days 2 to 5

Pediatric Mycoplasma Pneumonia

6 months and older

Immediate-release

  • 10 mg/kg (maximum: 500 mg/dose) orally on day 1, followed by 5 mg/kg (250 mg/dose) orally once a day on days 2 to 5

Extended-release

  • Patients less than 34 kg: 60 mg/kg (maximum dose: 2 g/dose) orally as a single dose
  • Patients 34 kg or greater: 2 g orally as a single dose

16 years and older

  • Parenteral: 500 mg IV once a day as a single dose for at least 2 days, followed by 500 mg (immediate-release formulation) orally to complete a 7- to 10-day course of therapy

IDSA and Pediatric Infectious Disease Society (PIDS) Recommendations
3 months to less than 5 years

  • Parenteral: 10 mg/kg on days 1 and 2 of treatment, transitioning to oral treatment when possible
  • Oral: 10 mg/kg orally on day 1, then 5 mg/kg/day orally once a day on days 2 to 5

5 years and older

  • Oral: 10 mg/kg (maximum: 500 mg/day) orally on day 1, followed by 5 mg/kg/day
  • maximum: 250 mg/day orally on days 2 to 5

Tonsillitis/Pharyngitis

2 years and older

  • Immediate-release: 12 mg/kg (maximum: 500 mg/dose) orally once a day for 5 days

Pediatric, Bacterial Infection

American Academy of Pediatrics (AAP) Recommendations

Immediate-release, Less than 1 month

  • IV: 10 mg/kg IV every 24 hours
  • Oral: 10 to 20 mg/kg orally every 24 hours

1 month or older

  • Mild to moderate infections: 5 to 12 mg/kg orally once a day
  • Severe infections: 10 mg/kg IV once a day

Skin and Structure Infection

IDSA Recommendations,

Immediate-release

  • Patients greater than 45 kg: 500 mg orally on day 1, then 250 mg orally once a day on days 2 through 5
  • Patients less than 45 kg: 10 mg/kg orally on day 1, then 5 mg/kg orally once a day for 4 additional days

Side Effects of Azithromycin

Most common

More common

Rare

Drug Interactions of Azithromycin

Azithromycin may interact with the following drugs, supplements, & may change the efficacy of drugs

Pregnancy Catagory

FDA Pregnancy Category – B

Pregnancy

  • There are no adequate data on the use of azithromycin in pregnant women. In reproduction toxicity studies in animals, azithromycin was shown to pass the placenta, but no teratogenic effects were observed. The safety of azithromycin has not been confirmed with regard to the use of the active substance during pregnancy. Therefore azithromycin should only be used during pregnancy if the benefit outweighs the risk.

Lactation

  • Azithromycin has been reported to be secreted into human breast milk, but there are no adequate and well-controlled clinical studies in nursing women that have characterized the pharmacokinetics of azithromycin excretion into human breast milk. In infertility studies conducted on the rat, reduced pregnancy rates were noted following administration of azithromycin. The relevance of this finding to humans is unknown.

FAQ