Metronidazole is an antiprotozoal and antibiotic medication. It’s effective against anaerobic bacteria and protozoan infections. It is used either alone or along with other antibiotics in treating bacterial infections like:
- Bacterial vaginosis
- Pelvic inflammatory disease
- Endocarditis
- Bacterial peritonitis
- Liver and pelvis abscess
- Septicemia or blood poisoning
- A dental infection like gum infections and tooth abscesses
- Osteomyelitis, a type of bone infection
- Stomach and intestinal ulcers caused by H. pylori
- Colorectal surgical infection
- Nongonococcal urethritis
- Crohn’s disease
- Perioral dermatitis
- Neonatal anaerobic infection
Protozoan infections like:
- Amebiasis is an infection of the intestine caused by the one-celled parasite amoeba.
- Trichomoniasis, a type of sexually transmitted disease caused by a certain parasite. Women with this type of parasitic infection have genital itching, foul-smelling vaginal discharge, and painful urination. Men, on the other hand, typically have no symptoms.
- Giardiasis, a type of diarrheal disease caused by the parasite Giardia. Also known as beaver fever, this type of infection is one of the most common causes of waterborne disease in the US.
Metronidazole kills protozoa and bacteria that interfere with their genetic material or DNA. It inhibits protein synthesis by interacting with the DNA. This causes a breakage in the helical structure and strands of DNA. Damages to the DNA structure and strands prevent new DNA from forming. Eventually, susceptible microorganisms will die and the infection will clear up.
Metronidazole is FDA for medical use since 1960. It’s one of the WHO lists of essential medicines. Unlike other antibiotics, Metronidazole is less likely to make bacteria resistant to it.
When and How to Use Metronidazole
The dose of Metronidazole depends on the type of infections you have, the strength of the medicine, and your other medical conditions. The most important thing to remember is that you have to take it exactly as directed by your physician.
- Bacterial anaerobic infections: The dose is 500 mg orally every 6 hours for 7 to 10 days. Some infections may require longer treatment duration.
- Sexually transmitted disease: Take 2 grams as a single dose along with other antibiotics
- Bacterial vaginosis: Take 500 mg twice a day for 7 days or 750 mg once a day for 7 days.
- Trichomoniasis: Take 2 grams as a single dose or divided doses on day 1. Take 250 mg three times a day on days 2 to 7.
- Pelvic inflammatory disease: Take 500 mg twice a day for 14 days along with other medicines prescribed to you by your doctor.
- C. difficile infection: Take 250 mg to 500 mg 4 times a day for 7 days.
The onset of action of Metronidazole can be observed within 1 to 2 hours after intake. The duration of the effect can last for an average duration of 24 hours.
For best results, take it at an evenly spaced time. Take it at the same time each day to help you remember. Continue taking your medicine even if you feel well. Finish the entire course of your treatment. Take it with or after food. Swallow the tablet whole with plenty of water.
Possible Side Effects of Metronidazole
Metronidazole is generally well-tolerated when used properly. The most common side effects are:
- Nausea
- A metallic taste
- Headache
- Loss of appetite
- Vomiting
- Diarrhea
- Weight loss
- Dry mouth
- Abdominal cramps
- Rash
- Constipation
- Vaginal dryness
- Nasal congestion
- Furry tongue
Side effects that may become serious are:
- Fever
- Stomatitis
- Cystitis
- Pain with urination
- Mouth sores
- Decrease in libido
- Pelvic pain or pressure
- Tingling or prickling sensation that may become permanent
Serious side effects that need medical attention include:
- Seizures
- Meningitis
- Damages to the nerves resulting in numbness and tingling of extremities
- Colon cancer
- Peripheral neuropathy
What should I know before taking Metronidazole?
- This medicine is suitable for treating infections in most adults and children. People who are allergic to this medicine should not use this. People with liver and kidney problems may need extra monitoring and a lower dose of Metronidazole.
- Do not use this if you are pregnant especially if you are in the first trimester. Doctors can only prescribe this medicine to pregnant women if considered essential.
- If you are breastfeeding, make sure that your doctor knows about it as this medicine can pass into breast milk and could give the milk a bitter taste.
- Metronidazole can interact with other medicines. Always let your doctor know what medicines you are taking including those without prescriptions, vitamins, herbal and dietary supplements.
Getting the Best Result from Metronidazole
- Finish the entire course of treatment. Stopping the medication too soon will not cure your condition. Bacteria or parasites will only become resistant to the antibiotic.
- Metronidazole is good at killing bacterial and parasitic infections but it won’t work against viral infections like flu and common colds. Like any other antibiotic, the use of this medicine when it is not needed can cause it to not work in future infections.
- Do not drink alcoholic beverages while taking this medicine and for at least three days after treatment. Alcohol and metronidazole together can cause vomiting, severe nausea, flushing, cramps, and headaches.
- Prolonged use of Metronidazole can lead to nerve damage or secondary infection. Symptoms may include the inability to walk straight, not being to speak, dizziness, shaking, and uncontrolled body movements. Use it exactly as directed. Do not use for longer than the required duration of treatment.
- Let your doctor know if you are on blood thinner as this medicine can make you likely to bleed.