Nitroimidazoles
Also known as: 5-nitroimidazoles, nitroimidazole antibiotics
Antibiotic and antiparasitic medicines, including metronidazole and tinidazole, that act on bacteria and parasites. The NHS says metronidazole is an antibiotic used for bacterial infections, including skin infections, mouth infections, bacterial vaginosis and pelvic inflammatory disease, and is available only on prescription. MedlinePlus says tinidazole treats trichomoniasis, bacterial vaginosis, giardiasis and amoebiasis, and describes it as a nitroimidazole antimicrobial.
- Also called
- 5-nitroimidazoles, nitroimidazole antibiotics
Mechanism of action
Microbial enzymes inside susceptible bacteria and parasites activate nitroimidazoles. The activated form then damages proteins and DNA. A study in Giardia found that metronidazole and tinidazole bind to the same subset of proteins. A therapeutic review says metronidazole has a limited spectrum that covers various protozoa and most anaerobic bacteria, and that it lacks efficacy against aerobic organisms. A review of tinidazole describes it as active in the laboratory against most clinically important anaerobic bacteria.
Members of the class
Members with a page on this site are linked.
Class effects
- LiverTox says tinidazole causes a low rate of raised liver enzymes during treatment, and rare cases of clinically apparent acute liver injury.
- The NHS lists feeling or being sick, diarrhoea and a slight metallic taste in the mouth as common side effects of metronidazole.
- MedlinePlus lists a sharp, unpleasant metallic taste among the side effects of tinidazole.
- The NHS lists yellowing of the skin or whites of the eyes among the rare but serious side effects of metronidazole.
Cautions
- For metronidazole, the NHS advises avoiding alcohol during treatment and for 2 days afterwards. Reactions listed include feeling or being sick, stomach pain, hot flushes, a pounding heartbeat and a headache.
- NCBI LiverTox describes tinidazole as a nitroimidazole similar to metronidazole, with a likely similar range and frequency of side effects.
- Tinidazole is broken down largely in the liver by an enzyme called CYP 3A4, which can lead to significant interactions with other medicines, according to LiverTox.
- MedlinePlus advises avoiding alcohol and products containing alcohol during tinidazole treatment and for a period afterwards, as they may cause an upset stomach, vomiting, stomach cramps, headaches, sweating and flushing.
- A review of alcohol and antibiotic interactions says the concern about alcohol with tinidazole rests on its chemical similarity to metronidazole, with no direct data identified.
- MedlinePlus advises telling the doctor about kidney or liver disease before using metronidazole.
Class interactions
Open the Drug Interaction Checker
Connected pages in detail
What each linked page on Anatomy Nexus covers, in a line, for Nitroimidazoles.
Medications
- Metronidazole An antibiotic used for bacterial infections of the skin, mouth and gums, and the vagina and pelvis, and the usual treatment for trichomoniasis.