Azithromycin is a broad-spectrum macrolide antibiotic derived from erythromycin. It is characterized by an expanded spectrum of activity, improved tissue penetration, and a significantly extended half-life allowing for short-course dosing regimens. The 200mg/5ml oral suspension is a commonly prescribed pediatric and adult formulation in India for treating community-acquired respiratory, skin, and soft tissue infections.
Adult: For most infections: 500 mg (12.5 ml of 200mg/5ml suspension) as a single dose on Day 1, followed by 250 mg (6.25 ml) once daily on Days 2 to 5. Total course dose: 1.5 g. For STIs like chancroid: Single 1 g (25 ml) dose.
Note: Shake the bottle well before each use. Use the provided measuring spoon or syringe for accurate dosing. Administer orally, on an empty stomach, at least 1 hour before or 2 hours after a meal. Maintain at least a 2-hour gap if taking antacids containing aluminum or magnesium.
Azithromycin reversibly binds to the 50S ribosomal subunit of susceptible bacteria, specifically to domain V of the 23S rRNA. This binding inhibits the translocation step of bacterial protein synthesis by blocking the transpeptidation/translocation reaction and the assembly of the 50S ribosomal subunit. It is primarily bacteriostatic but can be bactericidal at higher concentrations or against highly susceptible organisms.
Pregnancy: US FDA Pregnancy Category B. Animal studies have shown no risk, but adequate and well-controlled studies in pregnant women are lacking. Use during pregnancy only if clearly needed. Considered an alternative for treating chlamydial infections in pregnancy.
Driving: May cause dizziness or vertigo. Patients should be cautioned about operating machinery or driving until they are sure the medication does not adversely affect their alertness.
| Antacids (Aluminum/Magnesium hydroxide) | Reduced absorption of azithromycin. Separate administration by at least 2 hours. | Moderate |
| Warfarin | Potential increased anticoagulant effect and risk of bleeding. Monitor INR closely. | Major |
| Digoxin | Azithromycin may increase digoxin serum concentrations by altering gut flora. Monitor digoxin levels. | Moderate |
| Cyclosporine, Tacrolimus | Possible increased levels of these immunosuppressants. Monitor drug levels and renal function. | Moderate |
| Nelfinavir | Increases azithromycin serum levels. Monitor for increased azithromycin side effects. | Moderate |
| Drugs that prolong QT interval (e.g., Amiodarone, Quinidine, Sotalol, Fluoroquinolones, Antipsychotics) | Additive risk of QT prolongation and cardiac arrhythmias. Avoid concomitant use if possible. | Major |