A fixed-dose combination (FDC) of a second-generation fluoroquinolone antibiotic (Ofloxacin) and a 5-nitroimidazole antimicrobial (Ornidazole). This combination provides broad-spectrum coverage against both aerobic bacteria and anaerobic bacteria/protozoa, making it highly effective in treating mixed infections, particularly in the gastrointestinal, genitourinary, and pelvic regions. It is widely used in India for infectious diarrhea, pelvic inflammatory disease, and post-surgical prophylaxis/treatment.
Adult: One tablet (Ofloxacin 200mg + Ornidazole 500mg) twice daily. For severe infections: May be initiated as twice daily. Typical duration: 5-7 days for GI infections, up to 10-14 days for PID/surgical prophylaxis.
Note: Take tablet with a full glass of water, with or after food to minimize GI upset. Maintain adequate hydration. Do not crush or chew. Space doses evenly (approx. every 12 hours). Complete the full prescribed course even if symptoms improve.
Ofloxacin inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, enzymes essential for DNA replication, transcription, repair, and recombination. This leads to double-stranded DNA breaks and bacterial cell death. Ornidazole is a prodrug; its nitro group is reduced by intracellular electron transport proteins in anaerobic bacteria and protozoa, generating cytotoxic intermediates that damage microbial DNA and inhibit nucleic acid synthesis.
Pregnancy: CONTRANDICATED. Ofloxacin: Category C (animal studies show cartilage damage in immature animals). Ornidazole: Category C (mutagenic in bacteria; avoid, especially first trimester). Risk of teratogenicity and arthropathy.
Driving: Use with caution. May cause dizziness, lightheadedness, visual disturbances, or drowsiness. Patients should not drive or operate machinery until their response is known.
| Antacids (Al, Mg, Ca), Sucralfate, Iron, Zinc | Chelation reduces Ofloxacin absorption dramatically. | Major |
| Warfarin | Ofloxacin may potentiate anticoagulant effect; increased INR/bleeding risk. | Major |
| Theophylline | Ofloxacin inhibits CYP1A2, increasing Theophylline levels (toxicity risk). | Major |
| NSAIDs (e.g., Ibuprofen) | Increased risk of CNS stimulation and seizures. | Moderate |
| Corticosteroids (e.g., Prednisolone) | Increased risk of tendon rupture with Ofloxacin. | Major |
| Alcohol | Disulfiram-like reaction with Ornidazole (flushing, tachycardia, nausea). | Major |
| Phenobarbital, Phenytoin, Rifampicin | Induce CYP450, reducing Ornidazole levels. | Moderate |
| Cyclosporine | Ofloxacin may increase Cyclosporine levels; monitor renal function. | Moderate |
Same composition (Ofloxacin (200mg) + Ornidazole (500mg)), different brands: