GP Doctor 👨🏻‍⚕️👩🏻‍⚕️

🌀 Azithromycin

Uses:
🔹 Respiratory Tract Infections: Treats pneumonia, bronchitis, and sinusitis.
🔹 Skin and Soft Tissue Infections: Commonly used for cellulitis.
🔹 STIs: Effective against Chlamydia trachomatis and gonorrhea (with ceftriaxone).
🔹 Mycobacterial Infections: Part of therapy for Mycobacterium avium complex (MAC).
🔹 Traveler’s Diarrhea: Treats bacterial causes, especially Campylobacter jejuni.
🔹 Otolaryngologic Infections: Otitis media, pharyngitis.
🔹 COVID-19 (Off-label): Investigated for anti-inflammatory effects.

Antimicrobial Spectrum:
🔹 Active against Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Chlamydia trachomatis, Mycoplasma pneumoniae, and Legionella pneumophila.
🔹 Covers gram-positive, gram-negative, and atypical bacteria.
🔹 Limited anaerobic activity.

Dose:
🔹 Adults:
• Community-Acquired Pneumonia (Oral/IV):
• 500 mg on day 1, then 250 mg daily for 4 days.
• Chlamydia (Oral):
• 1 g single dose.
• Gonorrhea (Oral):
• 2 g single dose (with ceftriaxone).
• Mycobacterial Infections (Oral):
• 500 mg once daily.
🔹 Pediatrics:
• Otitis Media (Oral/IV):
• 10 mg/kg day 1, then 5 mg/kg for 4 days.
• Pharyngitis/Tonsillitis (Oral/IV):
• 12 mg/kg once daily for 5 days.
• Community-Acquired Pneumonia (Oral/IV):
• 10 mg/kg day 1, then 5 mg/kg for 4 days.

Presentation:
🔹 Tablets: 250 mg, 500 mg, 600 mg.
🔹 Oral Suspension: 100 mg/5 mL, 200 mg/5 mL.
🔹 IV Solution: 500 mg/vial.

Notes:
🔹 Mechanism of Action:
• Binds to the 50S ribosomal subunit, inhibiting bacterial protein synthesis.
🔹 Pharmacokinetics:
• Absorption: Rapid, bioavailability ~37%.
• Distribution: High tissue concentration.
• Half-life: ~68 hours.
• Metabolism: Minimal hepatic metabolism.
• Excretion: Mostly excreted in bile.
🔹 Side Effects:
• Common: Nausea, diarrhea, abdominal pain.
• Serious: QT prolongation, torsades de pointes, hepatotoxicity.
🔹 Contraindications:
• Hypersensitivity to azithromycin or macrolides.
• Cholestatic jaundice or liver dysfunction from prior use.
🔹 Drug Interactions:
• Antacids with magnesium/aluminum reduce absorption.
• Warfarin: May enhance anticoagulation effects.
• Caution with QT-prolonging drugs (e.g., amiodarone).
🔹 Special Considerations:
• Pregnancy and Lactation: Category B, generally safe.
• Elderly: Monitor for QT prolongation.
• Renal & Hepatic Impairment: Caution in severe liver disease.
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