[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Nitroimidazoles](https://durgical.com/en/pharmacology/classes/nitroimidazoles/) › Secnidazole

[Pharmacology](https://durgical.com/en/pharmacology/) · [Nitroimidazoles](https://durgical.com/en/pharmacology/classes/nitroimidazoles/)

# Secnidazole

A long-acting nitroimidazole given once, as granules on soft food, for bacterial vaginosis and trichomoniasis.

Updated 2026-11-01

- Class: [Nitroimidazoles](https://durgical.com/en/pharmacology/classes/nitroimidazoles/)
- Target: DNA of anaerobic bacteria and protozoa (after reduction of the nitro group)
- ATC code: P01AB07

## Mechanism of action

Like metronidazole, secnidazole is reduced inside anaerobic bacteria and Trichomonas to reactive radicals that damage DNA. Its long persistence in the body allows a single dose.

- Granules are swallowed with soft food
- The nitro group is reduced inside the microbe
- Radicals damage DNA
- The microbe dies

## Pharmacokinetics

**Absorption**
Oral granules, sprinkled on soft food; reaches breast milk, so breastfeeding is paused for four days after the dose.

## Indications

- Bacterial vaginosis [Bacterial vaginosis →](https://durgical.com/en/conditions/bacterial-vaginosis/)
- Trichomoniasis [Trichomoniasis →](https://durgical.com/en/conditions/trichomoniasis/)

## Adverse effects

### Common

- Headache
- Nausea, vomiting and diarrhoea
- Metallic or unpleasant taste

### Serious (rare, important)

- Vaginal yeast infection (thick white discharge, itching)

## Contraindications

- Allergy to secnidazole or other nitroimidazoles

## Key interactions

**Alcohol and propylene glycol**
Nausea, vomiting, cramps, headache, sweating and flushing; avoided during treatment and for two days after.

## What is monitored

- Symptoms after treatment
- Vaginal itching or discharge

## Administration and safety

- The whole packet is sprinkled on applesauce, yogurt or pudding and eaten within half an hour
- Granules are not chewed or crushed
- The granules are not mixed into water or other liquids

## Nursing care

- Teach the preparation of the granules
- Teach to avoid alcohol for two days after the dose
- Explain that sexual partners are treated in trichomoniasis
- Advise pausing breastfeeding for four days

## Pregnancy and breastfeeding

Human data are limited; pregnancy is discussed before use.

## Memory aid

«Secni = single»: one sachet, one meal, one dose.

## Test yourself

Think of the answer, then tap the question to see it.

## How is secnidazole taken?

As a single dose of granules sprinkled on soft food, not chewed.

## For which two infections is it used?

Bacterial vaginosis and trichomoniasis.

## How long is alcohol avoided after secnidazole?

During treatment and for two days afterwards.

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## Related drugs

- [Metronidazole](https://durgical.com/en/pharmacology/metronidazole/)
- [Tinidazole](https://durgical.com/en/pharmacology/tinidazole/)

## Related conditions

- [Bacterial vaginosis](https://durgical.com/en/conditions/bacterial-vaginosis/)
- [Trichomoniasis](https://durgical.com/en/conditions/trichomoniasis/)

[← Back to the class: Nitroimidazoles](https://durgical.com/en/pharmacology/classes/nitroimidazoles/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Secnidazole: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a617052.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=P01AB07) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/secnidazole/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/secnidazole/