Metronidazole

Metronidazole

Antibiotics Prescription only ATC code: J01XD01

What it is

Metronidazole is a nitroimidazole antibiotic active against anaerobic bacteria and several protozoa. Inside these organisms it is chemically reduced into reactive intermediates that break their DNA, which kills the cell. It is used for anaerobic bacterial infections and forms part of the combination regimens used to clear the bacterial cause of stomach and duodenal ulcers.

Typical dose
250–500 mg
3× a day
Times
With food

Used for

  • Bacterial infection
  • Ulcer

What to know while taking it

It is taken with food, which softens the nausea and stomach upset it often causes. A persistent metallic taste is common and harmless, and it fades after the course ends. Alcohol is avoided during the course and for a short period afterwards because the combination can cause flushing, vomiting and a pounding heartbeat. It increases the effect of warfarin, so bleeding risk rises. White cell counts and ALT may be checked, since the drug can lower white cells and irritate the liver.

When to see a doctor

See a doctor for numbness, tingling or burning in the hands or feet, for unusual bruising, sore throat or fever, or for yellowing of the skin or eyes. Unusual bleeding while also on warfarin, or a severe reaction after alcohol, also warrants prompt medical attention.

Worth knowing

  • Do not combine with alcohol
  • Finish the full course
  • Metallic taste is common

Interacts with

Markers to watch

Reference information, not medical advice. Discuss any change with your doctor.