FDA approved Zithromax (azithromycin) for Community-Acquired Pneumonia and Pelvic Inflammatory DiseaseFDA approved new injectable antibiotic Zithromax for two serious infections.

FDA From the archive Source published January 30, 1997 Summary added July 15, 2026 DOI ↗ Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

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Key Takeaway

Consider intravenous azithromycin for initial treatment of community-acquired pneumonia or pelvic inflammatory disease in adults requiring IV therapy.

The FDA has approved Zithromax (azithromycin) for injection for the treatment of community-acquired pneumonia and pelvic inflammatory disease in adults who require initial intravenous therapy. For community-acquired pneumonia, the recommended dose is 500 mg intravenously once daily for at least two days, followed by oral azithromycin 500 mg daily to complete a 7- to 10-day course. For pelvic inflammatory disease, the dose is 500 mg intravenously once daily for one or two days, followed by oral azithromycin 250 mg daily to complete a 7-day course. The approval underscores the importance of using Zithromax only for infections proven or strongly suspected to be caused by susceptible bacteria to reduce the development of drug-resistant bacteria. Clinicians should consider local epidemiology and susceptibility patterns when selecting empiric therapy.

＋ Clinical Details (Mechanism · Dosing · Trial Data · Warnings)

Mechanism of Action

Azithromycin is a macrolide antibacterial drug. It acts by binding to the 50S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis.

Indication & Patient Population

Zithromax for injection is indicated for the treatment of mild to moderate infections caused by designated susceptible bacteria in adults: community-acquired pneumonia due to Chlamydophila pneumoniae, Haemophilus influenzae, Legionella pneumophila, Moraxella catarrhalis, Mycoplasma pneumoniae, Staphylococcus aureus, or Streptococcus pneumoniae in patients requiring initial intravenous therapy; and pelvic inflammatory disease due to Chlamydia trachomatis, Neisseria gonorrhoeae, or Mycoplasma hominis in patients requiring initial intravenous therapy. If anaerobic microorganisms are suspected, an agent with anaerobic activity should be used in combination.

Dosing & Administration

For community-acquired pneumonia: 500 mg as a single daily dose intravenously for at least two days, followed by oral azithromycin 500 mg daily to complete a 7- to 10-day course. For pelvic inflammatory disease: 500 mg as a single daily dose intravenously for one or two days, followed by oral azithromycin 250 mg daily to complete a 7-day course. The infusate concentration should be 1 mg/mL over 3 hours or 2 mg/mL over 1 hour. Do not administer as a bolus or intramuscular injection. Reconstitute with 4.8 mL Sterile Water for Injection to yield 100 mg/mL. Dilute further to 1-2 mg/mL in compatible diluents. Stable for 24 hours at room temperature or 7 days refrigerated.

Key Clinical Trial Data

Trial data not available in label.

Warnings & Contraindications

Not reported in label.

Place in Therapy

Zithromax for injection provides an intravenous option for initial treatment of community-acquired pneumonia and pelvic inflammatory disease in adults, with a switch to oral therapy to complete the course. It should be used only for infections proven or strongly suspected to be caused by susceptible bacteria to minimize resistance development.

The FDA has approved Zithromax (azithromycin) for injection to treat two serious bacterial infections in adults: community-acquired pneumonia and pelvic inflammatory disease. This form of the drug is given through a vein (IV) and is meant for patients who need initial intravenous therapy. For pneumonia, the typical treatment is 500 mg IV once daily for at least two days, then switching to oral azithromycin 500 mg daily to complete a 7 to 10 day course. For pelvic inflammatory disease, the dose is 500 mg IV once daily for one or two days, followed by oral azithromycin 250 mg daily to complete a 7 day course.

This approval is important because it offers a new treatment option for these infections when IV therapy is needed. However, it is crucial to use Zithromax only for infections that are proven or strongly suspected to be caused by susceptible bacteria. This helps reduce the risk of antibiotic resistance, which happens when bacteria learn to defeat the drugs designed to kill them.

If you or a loved one has pneumonia or pelvic inflammatory disease, talk to your doctor about whether Zithromax injection is right for you. Your doctor will consider local infection patterns and your specific health needs. Remember, antibiotics like Zithromax do not work against viruses, such as those that cause colds or the flu.

What this means for you:

Zithromax injection is a new option for serious bacterial infections, but use only as prescribed to fight antibiotic resistance.

Study Details

Study typeFda approval

PublishedJan 1997

View Original Abstract ↓

1 INDICATIONS AND USAGE ZITHROMAX (azithromycin) for injection is a macrolide antibacterial drug indicated for the treatment of patients with infections caused by susceptible strains of the designated microorganisms in the conditions listed below. ZITHROMAX is a macrolide antibacterial drug indicated for mild to moderate infections caused by designated, susceptible bacteria: • Community-acquired pneumonia in adults ( 1.1 ) • Pelvic inflammatory disease ( 1.2 ) To reduce the development of drug-resistant bacteria and maintain the effectiveness of ZITHROMAX and other antibacterial drugs, ZITHROMAX should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. ( 1.3 ) 1.1 Community-Acquired Pneumonia due to Chlamydophila pneumoniae , Haemophilus influenzae , Legionella pneumophila , Moraxella catarrhalis , Mycoplasma pneumoniae , Staphylococcus aureus , or Streptococcus pneumoniae in patients who require initial intravenous therapy. 1.2 Pelvic Inflammatory Disease due to Chlamydia trachomatis , Neisseria gonorrhoeae , or Mycoplasma hominis in patients who require initial intravenous therapy. If anaerobic microorganisms are suspected of contributing to the infection, an antimicrobial agent with anaerobic activity should be administered in combination with ZITHROMAX. ZITHROMAX for injection should be followed by ZITHROMAX by the oral route as required. [see Dosage and Administration (2) ] 1.3 Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of ZITHROMAX (azithromycin) and other antibacterial drugs, ZITHROMAX (azithromycin) should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

FDA approved Zithromax (azithromycin) for Community-Acquired Pneumonia and Pelvic Inflammatory DiseaseFDA approved new injectable antibiotic Zithromax for two serious infections.

Study Details

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FDA approved Zithromax (azithromycin) for Community-Acquired Pneumonia and Pelvic Inflammatory DiseaseFDA approved new injectable antibiotic Zithromax for two serious infections.

Study Details

Intrawound tobramycin plus vancomycin did not reduce deep infection risk compared with vancomycin alone in high-risk tibial fractures

Adding Antibiotics to Bone Surgery Didn't Lower Infection Risk

Clinical research that matters. Delivered to your inbox.

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