Indications

Zibac (Azithromycin) is a macrolide antibiotic used to treat various infections caused by susceptible organisms. These include:

• Lower respiratory tract infections: Bronchitis and pneumonia.
• Upper respiratory tract infections: Sinusitis and pharyngitis/tonsillitis.
• Other infections: Otitis media, and skin and soft tissue infections.
• Sexually transmitted diseases: Non-gonococcal urethritis and cervicitis due to Chlamydia trachomatis.

Pharmacology

Azithromycin is a macrolide antibiotic that works by binding to the 50S ribosomal subunit of bacteria, interfering with protein synthesis. It is acid-stable and can be taken orally. The drug is readily absorbed and concentrates in phagocytes, which actively transport it to the site of infection. This results in a much higher concentration in tissues than in plasma, and its long half-life allows for once-daily dosing and a shorter treatment duration.

Dosage & Administration

• Oral (Adults):
  • For most infections: 500 mg once daily for 3 days, or a 5-day regimen of 500 mg on day 1, followed by 250 mg on days 2-5.
  • For Chlamydia trachomatis: A single 1 gm dose or a 3-day regimen (500 mg on day 1, then 250 mg for the next 2 days).
• Oral (Children > 6 months): 10 mg/kg body weight once daily for 3 days.
• Intravenous (Adults):
  • Community-acquired pneumonia: 500 mg once daily for at least 2 days, followed by oral therapy to complete a 7-10 day course.
  • Pelvic inflammatory disease: 500 mg once daily for 1-2 days, followed by oral therapy to complete a 7-day course.

Zibac should be taken at least 1 hour before or 2 hours after a meal. For the suspension, add boiled and cooled water up to the marked line and shake well.

Interaction

• Antacids: Take Zibac at least 1 hour before or 2 hours after antacids.
• Ergot derivatives: Do not co-administer due to the theoretical risk of ergotism.
• Cyclosporin/Digoxin: Co-administration requires monitoring of drug levels.
• Warfarin: Prothrombin time should be monitored if co-administered.

Contraindications

Zibac is contraindicated in patients with a hypersensitivity to Azithromycin or any other macrolide antibiotic, or in patients with hepatic disease.

Side Effects

Side effects are generally mild to moderate and are mostly gastrointestinal, including nausea, abdominal pain, vomiting, and diarrhea. Allergic reactions and, rarely, serious hypersensitivity reactions have been reported.

Pregnancy & Lactation

Azithromycin is a Pregnancy Category B drug. It should only be used during pregnancy if clearly needed, as adequate human studies are lacking. Caution should be exercised when administering to nursing mothers.

Precautions & Warnings

Caution is advised for patients with severe renal impairment, as there is a lack of data for this population. As the liver is the main route of excretion, it is contraindicated in patients with hepatic disease.

Overdose Effects

Overdosage may result in hearing loss, severe nausea, vomiting, and diarrhea. Gastric lavage and general supportive measures are recommended.

Therapeutic Class

Zibac is a macrolide antibiotic.