Metronidazole - oral

Patient Medicine Information
Why do I need this medicine?
Metronidazole is an antibiotic. It is used to treat infections of the stomach, intestines, pelvic area, genital tract, skin, lungs, blood, brain and bones.

This medicine may also be used in combination with other antibiotics to prevent infections after a surgery.

Metronidazole may be used to treat other conditions as decided by your doctor.
How do I take this medicine?
Take Metronidazole exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

This medicine is available as an oral tablet, capsule or oral suspension.

If you are taking the tablet or capsule, take it with food or immediately after a meal.

If you are taking the modified-release type of tablet (usually labelled “ER”), take it 1 hour before or 2 hours after a meal. Swallow it whole. Do not divide, chew or crush the tablet.

If you are taking an oral suspension, take it on an empty stomach, at least 1 hour before meal. Shake the bottle well before you take it to ensure that the liquid is evenly mixed. Use the measuring spoon or cup provided to measure out your prescribed dose.

Try to take it at the same time each day.

The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on the type and severity of your infection.

Take Metronidazole at regular intervals. You must complete the entire course of medicine. If you don't, the infection will not be properly controlled.
What should I do if I have forgotten to take this medicine?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor and pharmacist know.
When should I not use this medicine?
Do not take Metronidazole if you ever had an allergic reaction (rashes, breathlessness, swollen eyes) to this medicine or other similar medicine (e.g. nitroimidazole such as tinidazole).

Do not take this medicine if you have taken disulfiram (medicine used to treat alcohol dependence) in the last 14 days.
What should I take note of while taking this medicine?
Inform your doctor if you have the following conditions:
  • severe liver disease
  • kidney problems or undergoing dialysis treatment
  • with or a history of blood disease
  • nervous system disorder (disease of the brain, spinal cord or nerves)
  • epilepsy (fits or seizures)
  • Cockayne syndrome (a rare disorder characterised by unusually short height, premature aging, sensitivity to sunlight, visual and hearing problems)
Metronidazole when used to treat an infection of the genital area (trichomoniasis) may cause harm to your unborn child. If you are in the first trimester of pregnancy, inform your doctor immediately.

Do not breastfeed for 12-24 hours after taking this medicine.

Let your doctor know if you are pregnant or breastfeeding.

If you are going for certain laboratory tests or an operation, including minor surgery and dental work, inform your doctor or dentist that you are taking Metronidazole.

For as long as you are taking this medicine, you may need to have regular blood tests to check your body's response to the medicine. Your doctor will advise you about how often you need to have these tests.
What side effects could I experience?
Metronidazole may cause dizziness, drowsiness, or some problems with your eyesight. If affected, do not drive or take part in any activity in which you need to be alert.

Other side effects include any of the following: headache, nausea, vomiting, diarrhoea, stomach pain, loss of appetite, furry tongue, metallic taste in the mouth, and constipation.

Your urine may look darker in colour. This is normal while you are being treated with this medicine; do not be alarmed.

If you develop rashes, breathlessness, swollen mouth or eyes, stop taking Metronidazole and inform your doctor quickly. These could be signs of an allergic reaction.

Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
  • rashes with peeling of the skin or blistering of the lips, mouth or eyes accompanied by fever
  • signs of liver problems e.g. yellowing of the skin or eyes
  • severe stomach pain which may reach through to your back
  • fever, stiff neck, hallucination (seeing, hearing or feeling things that are not existent), confusion, muscle coordination problems, difficulty in speaking
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I take this with other medicines?
Do not take Metronidazole if you have taken disulfiram (medicine used to treat alcohol dependence) in the last 14 days.

Inform your doctor and pharmacist if you are taking any of these medicines:
  • medicines for epilepsy (seizures or fits) e.g. phenobarbital, carbamazepine, phenytoin
  • medicines for cancer e.g. busulfan, fluorouracil
  • blood-thinning medicines e.g. warfarin
  • medicines for depression e.g. lithium
  • medicines for organ transplant or certain immune disorders e.g. ciclosporin
This list does not include all medicines that may interact with Metronidazole.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
What special dietary instructions should I follow?
Avoid alcohol.

Do not take alcoholic beverages or products while you are taking Metronidazole and for 3 days after finishing the course of your treatment.
How should I store this medicine?
Store in a cool, dry place away from the reach of children. Protect from light.

Medicines must not be used past the expiry date.
This information is independently developed by MIMS based on metronidazole - oral and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 MIMS. All rights reserved. Powered by
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