Azithromycin (Zithromax®)

STI Standards

Midwives may independently prescribe, order, and administer drugs in the community, hospital or other sites of midwifery practice to treat sexually transmitted infections for clients in case, as designated under specialized practice certification. Midwives without specialized practice certification in sexually transmitted infections management are required to refer their clients to an appropriate health care practitioner for treatment. 

Azithromycin is a macrolide anti-infective antibiotic derived from erythromycin. Inhibits RNA dependent protein synthesis and binds to the 50S ribosomal subunit blocking transpeptidation.

Indications and Clinical Use:

For treatment of asymptomatic or symptomatic Chlamydia Trachomatis and neisseria gonorrhea in pregnancy and the postpartum.


Documented hypersensitivity or allergy to azithromycin or any component of the formulation and if there is a history of cholestatic jaundice/hepatic dysfunction.

Warnings and Precautions:

Use with caution in those with liver disease. Use should be discontinued with nausea, vomiting and/or fever. Macrolides have been associated with rare QTc prolongation and ventricular arrhythmias. Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months post-antibiotic treatment.

Breastfed infants may develop vomiting, diarrhea, and/or rash. Modification of bowel flora in the infant may occur.


Human data does not suggest risk of toxicity during embryo-fetal development.


Limited Data – probably compatible.
No reported pediatric concerns for neonates exposed to breastmilk.

Adverse Reactions:

Diarrhea, loose stools, abdominal pain, nausea, vomiting.

Dosage and Administration:

Chlamydia Trachomatis:
Azithromycin (Zithromax®): 1 g orally in single dose.

Neisseria Gonorrhea:
Azithromycin (Zithromax®)
– if pregnant: 1 g orally in a single dose.
– if not pregnant: 2 g orally in a single dose.

Onset of Action:

Oral: Rapid; aluminum and magnesium containing antacids may slow absorption of azithromycin.

Duration of Action:

Peak serum concentrations usually attained within 3–4 hours.
Half-life: 48-68 hours.