Levofloxacin is a broad-spectrum, third-generation fluoroquinolone antibiotic. It is the pure (-)-(S)-enantiomer of the racemic drug ofloxacin, offering enhanced antibacterial activity and a favorable pharmacokinetic profile. It is bactericidal and works by inhibiting bacterial DNA gyrase and topoisomerase IV, enzymes critical for DNA replication, transcription, repair, and recombination. It is widely used in the Indian healthcare setting for treating a variety of community-acquired and hospital-acquired bacterial infections.
Adult: 500 mg orally or IV once every 24 hours. Duration varies: 7-14 days for CAP/sinusitis, 10-14 days for cUTI/pyelonephritis, 28 days for chronic bacterial prostatitis.
Note: Can be taken with or without food. Tablets should be swallowed whole with a full glass of water. Maintain adequate hydration. Do not take with dairy products, calcium-fortified juices, or antacids containing magnesium/aluminum, calcium, iron, or zinc; separate by at least 2 hours before or 4 hours after levofloxacin dose.
Levofloxacin exerts its bactericidal effect by inhibiting two essential bacterial type II topoisomerase enzymes: DNA gyrase (primarily in Gram-negative bacteria) and topoisomerase IV (primarily in Gram-positive bacteria). This inhibition interferes with DNA supercoiling, replication, transcription, and repair, leading to double-stranded DNA breaks and rapid bacterial cell death.
Pregnancy: Pregnancy Category C (US FDA). Animal studies show fetal arthropathy. There are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus. Generally avoided in pregnancy in India.
Driving: May cause dizziness, lightheadedness, or visual disturbances. Patients should be cautioned about operating vehicles or machinery until their response to the drug is known.
| Antacids (Al, Mg), Sucralfate, Multivitamins with Zinc/Iron, Dairy Products | Form chelation complexes, drastically reducing levofloxacin absorption and bioavailability. | Major |
| Corticosteroids (e.g., Prednisolone) | Concomitant use increases the risk of tendon rupture, especially in elderly. | Major |
| NSAIDs (e.g., Ibuprofen, Diclofenac) | May increase the risk of CNS stimulation and seizures. | Moderate |
| Oral Anticoagulants (Warfarin) | May enhance anticoagulant effect; monitor INR closely. | Moderate |
| Antiarrhythmics (Amiodarone, Sotalol), Antipsychotics, TCAs, Macrolides | Additive effect on QT interval prolongation, increasing arrhythmia risk. | Major |
| Theophylline | Levofloxacin may inhibit theophylline metabolism, increasing theophylline levels and toxicity risk. | Moderate |
| Cyclosporine | May increase serum creatinine; monitor renal function. | Moderate |
| Probenecid | Reduces renal tubular secretion of levofloxacin, increasing its serum levels and half-life. | Moderate |
| Insulin, Oral Hypoglycemics | May cause hyperglycemia or hypoglycemia; monitor blood glucose. | Moderate |