Metronidazole: What is it and what is it used for?

What is metronidazole?

Metronidazole is a synthetic antibiotic drug, which belongs to the group of nitroimidazoles with antibacterial and antiparasitic properties, which is used in human health, in the treatment of infections caused by pathogenic microorganisms. (1)

What is metronidazole used for?

• Metronidazole has a mechanism of action on anaerobic bacteria (2) which multiply without the need for oxygenation, intervening in the synthesis of macromolecules and proteins of these organisms. 
• It is used to treat:
  • Bacteroides fragilis or giardiasis infections . (3)
  • Helicobacter pylori bacterial infections .
  • Bacterial infections in the central nervous system (CNS).
  • Entamoeba histolytica infection .
  • Gastrointestinal and respiratory tract infections .
  • Gynecological infections such as bacterial vaginosis.
  • Skin , bone and blood infections.

Dosage and routes of administration of metronidazole

The presentations of metronidazole are varied and can be in 250 mg and 500 mg tablets ; in suppositories of 500 mg; 7.5mg/g gel; injections of 5 mg/mL intravenously or in suspension with content of 125 mg/5 mL. Metronidazole doses depend on the judgment of the treating physician , but are generally used as follows:

• Tablets: This presentation is used to treat a large number of infections due to different bacteria, varying the dosage between a 250 mg tablet every 8 hours to a single dose of 2 grams per day, depending on medical evaluation.
• Suppositories or tablets of 500 mg: To treat cases of bacterial infections in women, the recommended dose is one suppository (500 mg) vaginally at night for a period of 10 days, in combination with oral treatment.
• 7.5 mg/g gel: To treat skin infections, one topical application every 12 hours (morning and night) for as long as the doctor indicates.
• 5 mg/mL injections: Adults and children over 12 years: 500 mg every 8 hours intravenously . Children under 12 years: 7.5 mg of metronidazole (1.5 ml of solution) per kilo of body weight, every 8 hours. In both cases, prior medical evaluation.
• 125 mg/5 mL suspension: In children under 10 years of age, 40 mg/kg is usually given orally as a single dose or 15-30 mg/kg/day divided into 2-3 doses during.

Note: The information presented here is for reference only and in this sense the recommendation of the medical specialist prevails.

What products contain metronidazole?

Some of the medicines that contain metronidazole are:

• Vagitrol®
• Flagenase®
• Flegyl®
• Metrogel®

Vagitrol®

• Vagitrol® are ovules that are composed of metronidazole, nystatin and fluocinolone acetonide.
• It is used in the treatment of vaginal infections caused by germs and parasites.
• See What is vagitrol and what is it for? , for more relevant information about this medicine.

Flagenase®

• Flagenase® is a drug whose active ingredient is metronidazole .
• It is used to treat many sexually transmitted infections, respiratory infections, and infections of the gastrointestinal system.
• For more information about this medicine, see What is flagenase and what is it used for? . 

Flegyl®

• Flegyl® is an antibiotic medicine whose main component is metronidazole, in different presentations.
• It is used to treat gynecological infections, respiratory and digestive tract infections.

Metrogel®

• Metrogel® is an antibiotic gel medication, composed of metronidazole for topical use.
• It is indicated for the treatment of erythema , papules and pustules that characterize rosacea.

Metronidazole Side Effects 

Treatment with metronidazole can cause certain adverse reactions in some patients, such as those described below:

• Allergic reactions from contact with metronidazole.
• dizziness
• Headache.
• vomiting .
• Itching.
• metal taste
• Rarely, reversible peripheral neuropathy.

Important: If you observe any of these adverse effects or another not included in the list, stop its consumption and consult your doctor .

Contraindications and warnings of metronidazole 

Treatment with metronidazole is contraindicated in the following cases:

• Hypersensitivity to the active metabolite.
• Renal insufficiency.
• Liver failure.
• Epilepsy.
• Blood abnormalities.

You should know: It is recommended to provide your doctor with complete information about your medical history.

Avoid if you have:

• CNS disease.
• Disulfiram medication or if you have taken it within the last 2 weeks.
• If you have had Crohn’s disease or heart, kidney and liver disease.

Warnings:

• Do not take alcohol or alcohol-based medications 12 hours before and 24 to 48 hours after treatment.
• Metronidazole should be used with caution during pregnancy.
• If you have an upset stomach, take it with food.
• Do not take without a prescription.
• Keep this drug out of the reach of children.
• Avoid self-medicating.