secnidazole

Secnidazole is a nitroimidazole antimicrobial used to treat certain protozoal infections and anaerobic bacterial infections. It is closely related to metronidazole and tinidazole and is active against organisms such as Giardia lamblia, Entamoeba histolytica, and Trichomonas vaginalis, as well as some anaerobic bacteria. In many regions, it is available as an oral tablet and is notable for the potential to use single-dose regimens.

Mechanism of action involves reduction of the nitro group by anaerobic organisms to reactive intermediates that damage DNA and inhibit nucleic acid synthesis, leading to cell death. The drug exhibits selective activity in anaerobic environments, where the activating conditions prevail.

Administration and dosage: secnidazole is typically given by mouth and, due to its relatively long half-life among nitroimidazoles, is suitable for single-dose regimens in certain infections. Commonly, a 2 g single dose is used for some indications such as bacterial vaginosis or trichomoniasis, though regimens may vary by guideline and region.

Pharmacokinetics: after oral administration, secnidazole is well absorbed with good bioavailability and wide tissue distribution. It is metabolized in the liver and eliminated mainly via the kidneys and to a lesser extent in feces. Its longer elimination half-life compared with some alternatives supports single-dose administration.

Safety and cautions: common adverse effects include nausea, headache, and a metallic taste; less frequent effects include vomiting and abdominal discomfort. Rare neurologic or hypersensitivity reactions can occur. Alcohol consumption should be avoided during therapy and for at least 24 to 48 hours after completion due to risk of a disulfiram-like reaction. Caution in pregnancy, particularly in the first trimester, and in hepatic impairment or when co-administered with anticoagulants. If hypersensitivity to nitroimidazoles is present, secnidazole should be avoided.