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By Medicover Hospitals / 29 Nov 2020
Home | Medicine | Metronidazole

What is Metronidazole?

Metronidazole is an antibiotic that helps in fighting with bacteria. This is used for treating many bacterial infections that are caused in vagina, stomach, intestines, liver, skin, joints, brain, heart and respiratory tract. Immediate-release drugs are released in the body right away and extended-release drugs are released slowly in the body. Immediate-release drugs and extended-release drugs are available in the form of generic drugs.

  1. Metronidazole uses
  2. Metronidazole side effects
  3. Precautions
  4. Metronidazole dosage
  5. Metronidazole storage
  6. Frequently Asked Questions
  7. Citations

Metronidazole Uses:

These are used to stop the growth of bacteria and parasites. Metronidazole antibiotics are used to treat many bacterial and parasitic infections. These tablets are not used for viral infections such as cold and flu. The tablets are also used to treat sexually transmitted diseases. These medications are also called as nitroimidazole antimicrobials. If the antibiotic is used without its need then it can increase the risk of getting some infection.

Metronidazole Side Effects:

Common metronidazole side effects are:

  • Vomiting
  • Nausea
  • Diarrhea
  • Constipation
  • Stomach problem
  • Stomach cramps
  • Loss of appetite
  • Headache
  • Dry mouth
  • Mouth or tongue irritation

Major side effects of Metronidazole are:

  • Numbness
  • Rash
  • Seizures
  • Itching
  • Hives
  • Peeling
  • Flushing
  • Stuffy nose
  • Joint Pain
  • Dizziness
  • Difficult in speaking
  • Agitation

If you have any of these serious symptoms immediately contact your doctor for further assistance. In any case, due to Metronidazole if you get any kind of reactions in your body try avoiding it.
A doctor advised you to take the medicines by seeing your problems and the benefits of this medicine are greater than the side effects. Majority of the people who use this medicine don’t show any side effects. Get medical help immediately if you get any serious Metronidazole side effects.


Before taking these tablets visit your doctor and tell him if you are allergic to any of the medications. If you’re taking any medications, vitamins, nutritional supplements or any herbal products share it with your doctor to avoid any medical emergencies.
Talk to your doctor if you have following diseases:

  • Crohn’s disease
  • Kidney disease
  • Liver disease

Avoid consumption of alcoholic beverages or any tobacco product while taking Metronidazole tablets. Alcohol consumption can cause some serious illness and can lead to nausea, vomiting, stomach cramps, headaches, sweating and redness of the face.

How to get rid of the side effects?

  • Nausea:Take metronidazole tablets after your meal or snacks. Avoid eating heavy or spicy meals.
  • Vomiting or Diarrhea:Try drinking enough water for avoiding dehydration. Take small sips of warm water if you’re vomiting. If diarrhea and vomiting last for more than 24hours then consult with the doctor for avoiding any medical emergencies.

How to take Metronidazole tablets?

Metronidazole tablets are taken once in a day or it can be divided into two doses for up to 10 days. The extended-release tablets are taken at least once in a day before 1 hour or after 2 hours of meal. Follow the directions that are prescribed in the prescription or consult a doctor before taking the medicines.

Swallow the full tablets without crushing or breaking it. Drink enough water to avoid vomiting. Try to complete the full dosage of the tablets even after you feel better.

Forms of Metronidazole:

Generic: Metronidazole (tablets) -250 mg, 500 mg


Adult dosage:Dosage depends on the infection type
Bacterial Infection:Take 500 mg dose four times a day for at least 7-19 days.
Amoebic infections:Take 500 mg or 750 mg dose three times a day for 5-10 days.
Trichomoniasis:Take 250 mg dose three times a day for 7 days

Missed Dosage:

Missing one or two-dose of Metronidazole won’t show any effect on your body. The skipped dose causes no problem. But with some medication, it won’t work if you don’t take the dosage on time. If you miss a dose some sudden chemical change may affect your body. In some cases, your doctor would advise you to take the prescribed medicine as soon as possible if you have missed the dose.


Overdose of a drug can be accidental. If you have taken more than the prescribed Metronidazole tablets there is a chance of getting a harmful effect on your body’s functions. Overdose of a medicine can lead to some medical emergency.

Metronidazole Warnings:

  • Cancer
  • Effects on the nervous system
  • Allergy reactions

People with Serious Health Conditions:

People with liver disease: If a person is suffering from liver disease try avoiding the usage of this drug. Or before taking Metronidazole tells your doctors about the problems you are facing.
People with kidney disease: If you are having kidney disease then your body may process the drug very slowly. This can increase the amount of drug and it can increase the high risk of side effects.
Pregnant women: Metronidazole is not evaluated for pregnant women. If a woman is using the drug during her pregnancy there is no such high risk of pregnancy loss, birth defects or any other problems. But to be on safe side consult your doctor before taking the medicine.
Breastfeeding: Metronidazole passes into the breast milk. It can cause some side effects to child’s who are breastfed. These can include diarrhea, vomiting and rash. Before taking Metronidazole while breastfeeding consult your doctor.


Direct contact with heat, air and light may damage your medicines. The exposure of medicine may cause some harmful effects. The medicine must be kept in a safe place and out of children’s reach.
Mainly the drug should be kept at room temperature between 68ºF and 77ºF (20ºC and 25ºC).
Before taking Metronidazole consult your Doctor. In case if you face any problems or side effects after taking Metronidazole rush immediately to your nearby hospital or consult your doctor for better treatment. Carry your medications always in your bag while travelling to avoid any immediate emergencies. Follow your prescription and follow your Doctor advice whenever you take Metronidazole.

Metronidazole vs Azithromycin:

Metronidazole Azithromycin
Metronidazole is an antibiotic that helps in fighting with bacteria It is Macrolide antibiotic
Side effects of Metronidazole are vomiting, nausea, stomach cramps and loss of appetite. Side effects of Azithromycin are Rash, nervousness, tongue discolouration and indigestion
These are used to stop the growth of bacteria and parasites It is used for the treatment of infections that are caused by bacteria such as bronchitis, pneumonia and infections of skin, throat, sinuses, lungs, ears and reproductive organ

Frequently Asked Questions:

Metronidazole can cause yeast infection. The symptoms that it shows are itching and discharge during or after the treatment with metronidazole infections.
Avoid the consumption of alcohol if you’re taking Metronidazole. Also, try to avoid food that contains propylene glycol. Consumption of these things can show you some major side effects like stomach cramps, vomiting, nausea and headaches.
There is no such need to avoid any dairy products while having Metronidazole tablets. Rather it should be taken with water or milk.
Chlamydia can be treated by Metronidazole tablets. 500mg one time a day or at least 7-19 days.


  • Metronidazole,
  • Safety of metronidazole in pregnancy: A meta-analysis,
  • Emergence of reduced susceptibility to metronidazole in Clostridium difficile,