Metronidazole

1 medicine

Metronidazole is an antibiotic used for anaerobic bacterial and parasitic infections, including some dental, gut and vaginal infections. Alcohol must be avoided during treatment and for 48 hours after the last dose, the combination can cause a severe reaction.

Flagyl

Metronidazole

200/400mg

Flagyl is a antibiotics medication containing Metronidazole, available as 200/400mg tablets.

from $0.34 / tablet View

Key facts

  • Metronidazole treats infections caused by anaerobic bacteria and certain parasites, organisms that thrive without oxygen, by damaging their DNA.
  • It's usually taken two or three times a day with food, for a course lasting days to a couple of weeks depending on the infection.
  • Never drink alcohol while taking metronidazole or for 48 hours after your last dose: the combination can cause severe flushing, nausea, vomiting and a fast heartbeat.
  • Seek urgent care for numbness or tingling in your hands or feet, seizures, or severe abdominal pain.

What Metronidazole treats

Metronidazole treats bacterial vaginosis and trichomoniasis, Giardia and amoebic dysentery, anaerobic dental and abdominal infections, some pelvic infections, and C. difficile colitis. It has no effect on viral or fungal infections.

How Metronidazole works

Once inside susceptible bacteria or parasites, metronidazole is converted into a reactive form that breaks apart their DNA, stopping the organism surviving or multiplying. Human cells don't activate the drug this way, which limits the effect to the target organisms.

Before you take it

  • Do not drink any alcohol, including in foods, mouthwash or other medicines, from when you start metronidazole until 48 hours after your last dose.
  • Tell your prescriber if you're pregnant, particularly in the first trimester, or breastfeeding, or if you have severe liver disease; your dose may need adjusting.
  • Tell your prescriber about warfarin or other blood thinners; metronidazole can increase their effect, and your clotting levels may need closer monitoring.
  • Long or repeated courses raise the risk of nerve damage; report any tingling or numbness promptly.

Side effects

Nausea, a metallic taste, and darkened urine, which is harmless, are common.

Stop and seek urgent medical care for any of these:

  • Numbness, tingling or weakness in the hands or feet.
  • Seizures, confusion, or difficulty with coordination.
  • Severe or persistent abdominal pain, or watery or bloody diarrhoea.
  • Hives, facial swelling or difficulty breathing.

Safety essentials

  • Avoid alcohol completely during treatment and for a full 48 hours after finishing; the reaction, flushing, vomiting and a racing heart, can be severe.
  • Finish the entire course even once symptoms improve; stopping early can let the infection return and adds to antibiotic resistance.
  • Tell your prescriber if you notice tingling or numbness in your limbs, this can signal nerve damage that needs the drug stopped.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.