A fixed-dose combination (FDC) of a broad-spectrum fluoroquinolone antibiotic (Ciprofloxacin) and a nitroimidazole antiprotozoal/antibacterial agent (Tinidazole). This combination is primarily used in the Indian market for the treatment of mixed aerobic-anaerobic infections, particularly in the gastrointestinal and genitourinary tracts, where both antibacterial and anti-protozoal/anti-anaerobic coverage is required. The FDC is rationalized for improved patient compliance in specific infections but is subject to regulatory scrutiny regarding its widespread use.
Adult: One tablet (Ciprofloxacin 500mg + Tinidazole 600mg) every 12 hours. For specific protozoal infections, a once-daily or single-dose regimen of tinidazole may be used, but the FDC is typically dosed twice daily for mixed infections. Duration: Usually 5-7 days, up to 10-14 days for severe/protracted infections.
Note: Take tablet with a full glass of water, with or without food (taking with food may reduce GI upset). Maintain adequate hydration. Do not crush or chew. Administer at least 2 hours before or 4 hours after antacids, sucralfate, divalent/trivalent cations (iron, calcium, zinc, magnesium) to avoid severe reduction in ciprofloxacin absorption.
Ciprofloxacin inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, enzymes essential for DNA replication, transcription, repair, and recombination. This leads to rapid bactericidal activity. Tinidazole undergoes intracellular reduction of its nitro group by microbial nitroreductase enzymes, generating cytotoxic intermediates that damage microbial DNA and inhibit nucleic acid synthesis, leading to cell death.
Pregnancy: CONTRANDICATED in the first trimester (Tinidazole is teratogenic in animals). Use in second and third trimesters only if potential benefit justifies the potential risk to the fetus (Pregnancy Category C for Ciprofloxacin, Category D for Tinidazole in 1st trimester).
Driving: May impair mental and/or physical abilities required for driving or operating machinery. Dizziness, lightheadedness, visual disturbances, and drowsiness have been reported. Patients should be cautioned.
| Antacids (Al, Mg, Ca), Sucralfate, Iron, Zinc | Markedly reduced absorption of ciprofloxacin due to chelation. | Major |
| Warfarin | Increased anticoagulant effect (Ciprofloxacin inhibits metabolism; Tinidazole may also potentiate). Increased risk of bleeding. | Major |
| Theophylline | Ciprofloxacin inhibits CYP1A2, increasing theophylline levels and risk of toxicity (seizures, arrhythmias). | Major |
| Tizanidine | Ciprofloxacin dramatically increases tizanidine levels (CYP1A2 inhibition), causing severe hypotension and sedation. | Contraindicated |
| Oral Hypoglycemics (Sulfonylureas) | Ciprofloxacin can potentiate hypoglycemic effect, leading to severe hypoglycemia. | Major |
| Phenytoin | Tinidazole may inhibit metabolism, increasing phenytoin levels and risk of toxicity. | Moderate |
| Lithium | Ciprofloxacin may increase lithium levels and risk of toxicity. | Moderate |
| NSAIDs (e.g., Ibuprofen) | May increase the risk of CNS stimulation and seizures with ciprofloxacin. | Moderate |
| Alcohol | Disulfiram-like reaction with Tinidazole (flushing, palpitations, nausea, vomiting). | Major |
Same composition (Ciprofloxacin (500mg) + Tinidazole (600mg)), different brands: