Satranidazole is a second-generation 5-nitroimidazole derivative antimicrobial and antiprotozoal agent. It is structurally related to metronidazole but designed to have a broader spectrum of activity, improved pharmacokinetics, and a better safety profile, particularly regarding neurotoxicity. It is primarily used in the treatment of amoebiasis, giardiasis, trichomoniasis, and anaerobic bacterial infections. Its mechanism involves the biochemical reduction of its nitro group, leading to cytotoxic effects within susceptible microorganisms.
Adult: Amoebiasis/Giardiasis: 500 mg twice daily for 3-5 days. Amoebic Liver Abscess: 500 mg twice daily for 5-10 days. Trichomoniasis: Single 2g dose (four 500mg tablets) or 500 mg twice daily for 5-7 days.
Note: To be taken orally after food to minimize gastrointestinal upset. Tablets should be swallowed whole with a full glass of water. Do not crush or chew.
Satranidazole is a prodrug. Its nitro group (NO2) is reduced intracellularly by low-redox potential electron transport proteins (ferredoxin or flavodoxin) found in anaerobic bacteria and protozoa. This reduction forms short-lived, cytotoxic nitro radical anions. These radicals cause strand breaks in microbial DNA, inhibit nucleic acid synthesis, and disrupt the helical structure of DNA, leading to cell death.
Pregnancy: Category C (as per some regulatory bodies; considered Category B by some experts due to structural differences from metronidazole). Contraindicated in the first trimester. Use in second and third trimesters only if potential benefit justifies potential fetal risk. Avoid high-dose regimens.
Driving: May cause dizziness, vertigo, or visual disturbances. Patients should be cautioned about operating machinery or driving until they are sure they are not affected.
| Alcohol (Ethanol) | Disulfiram-like reaction: flushing, palpitations, nausea, vomiting. | Major |
| Warfarin and other Coumarin Anticoagulants | Satranidazole may potentiate anticoagulant effect, increasing INR and risk of bleeding. | Major |
| Lithium | May increase lithium serum levels and risk of toxicity. | Moderate |
| Phenobarbital, Phenytoin | May increase metabolism of satranidazole, reducing its efficacy. | Moderate |
| Cyclosporine, Tacrolimus | Potential increase in calcineurin inhibitor levels, increasing risk of nephrotoxicity. | Moderate |
| 5-Fluorouracil (5-FU) | Satranidazole may reduce clearance of 5-FU, increasing toxicity risk. | Moderate |
Same composition (Satranidazole (500mg)), different brands: