A fixed-dose combination (FDC) of a broad-spectrum fluoroquinolone antibiotic (Levofloxacin) and a macrolide antibiotic (Azithromycin). This combination provides synergistic and broad-spectrum coverage against a wide range of Gram-positive, Gram-negative, and atypical pathogens, including intracellular organisms. It is primarily used for the treatment of severe or complicated respiratory tract infections, pelvic inflammatory disease, and certain mixed infections where monotherapy may be insufficient. The combination leverages the rapid bactericidal action of levofloxacin with the prolonged tissue penetration and anti-inflammatory properties of azithromycin.
Adult: One tablet (Levofloxacin 500mg + Azithromycin 500mg) orally, once daily. Duration: Typically 5-10 days for respiratory infections; for PID, often a single dose of azithromycin component is part of a longer regimen. MUST be based on severity, pathogen, and clinical response.
Note: Take tablet at least 1 hour before or 2 hours after meals (for optimal absorption of levofloxacin). Can be taken with food if GI upset occurs, but absorption may be slightly delayed. Swallow whole with a full glass of water. Maintain adequate hydration. Do not take with antacids, sucralfate, or multivitamins containing iron, zinc, or magnesium; separate administration by at least 2 hours before or 4 hours after.
This combination exerts a dual bactericidal and bacteriostatic action by inhibiting two different essential bacterial processes. Levofloxacin inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, enzymes required for DNA replication, transcription, repair, and recombination. Azithromycin binds to the 50S ribosomal subunit of susceptible bacteria, inhibiting RNA-dependent protein synthesis. The combination can be synergistic against some organisms and provides coverage against a broader spectrum, including intracellular pathogens.
Pregnancy: Levofloxacin: Category C (US FDA). Animal studies show fetal arthropathy. Avoid in pregnancy unless no safer alternative exists. Azithromycin: Category B (US FDA). Considered relatively safer. However, the combination should be avoided during pregnancy. Use only if potential benefit justifies potential fetal risk.
Driving: May cause dizziness, lightheadedness, or visual disturbances. Patients should be cautioned about operating machinery or driving until they are certain the medication does not affect them adversely.
| Antacids (Al, Mg), Sucralfate, Iron/Zinc Supplements | Markedly reduced absorption of levofloxacin due to chelation | Major |
| Warfarin | Increased anticoagulant effect and risk of bleeding (Azithromycin may inhibit warfarin metabolism) | Major |
| Drugs prolonging QT interval (Class IA/III antiarrhythmics, TCAs, antipsychotics) | Additive risk of life-threatening cardiac arrhythmias (Torsades de Pointes) | Contraindicated/Major |
| Theophylline | Levofloxacin may increase theophylline levels; risk of toxicity | Moderate |
| Cyclosporine | Azithromycin may increase cyclosporine levels; monitor renal function and cyclosporine levels | Moderate |
| Digoxin | Azithromycin may increase digoxin bioavailability; monitor for digoxin toxicity | Moderate |
| Ergotamine/Dihydroergotamine | Increased risk of ergotism (vasospasm) with azithromycin | Major |
| NSAIDs | May increase the risk of CNS stimulation and seizures with levofloxacin | Moderate |
| Corticosteroids (systemic) | Increased risk of tendon rupture with levofloxacin | Major |