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By: RSC Editorial Team

April 4, 2023

Can Metronidazole Cause Yeast Infections?

If you develop symptoms of an infection, your doctor may prescribe Metronidazole to help you get better. Most people take Metronidazole without problems, but occasionally, complications arise.

When taking Metronidazole, you may notice symptoms such as itching, burning, or painful urination. If so, you may be asking, “Can Metronidazole cause yeast infections?” Unfortunately, it’s possible. In this guide from Rapid STD Testing, you’ll learn more about Metronidazole and the drug’s role in causing yeast infections.

What Is Metronidazole?

Metronidazole is an antibiotic commonly prescribed to treat infections. One of its brand names is Flagyl (or Flagyl ER for the extended-release formula). Your doctor may prescribe you Metronidazole for:

  • Pelvic inflammatory disease
  • Certain vaginal infections, such as bacterial vaginosis, which can cause preterm delivery in pregnant women
  • Rosacea
  • Dental infections
  • Gastrointestinal infections
  • Skin infections
  • Trichomoniasis

Metronidazole can only treat parasitic and bacterial infections. For viral infections, such as the common cold, influenza, or COVID-19, Metronidazole will not work. Neither can you use Metronidazole to treat certain STDs, such as herpes and HPV. If you suspect you have an STD, consider taking a rapid STD test to find out.

If you’re wondering, “Does Metronidazole cure yeast infections?” the answer is no. Yeast infections are caused by the overgrowth of a fungus called Candida. Metronidazole doesn’t treat fungal infections, so it can’t cure a yeast infection. You’ll need to use an antifungal cream instead.

Prescribed Usage

The prescribed usage for Metronidazole depends on the drug’s form and the condition you’re treating. Metronidazole comes as a capsule, tablet, or extended-release tablet. It’s also available as a cream to treat vaginal infections, particularly bacterial vaginosis.

Metronidazole tablets and capsules are usually prescribed as a one-time dose or two daily doses. In some cases, your doctor may tell you to take the drug two to four times daily for 10 days or longer. If your doctor prescribes extended-release Metronidazole, you’ll take it daily for up to seven days, either one hour before or two hours after a meal. Carefully read the directions for your prescription to ensure you take the right dose at the correct time.

If your doctor prescribes you vaginal Metronidazole, you’ll need to use it for five nights in a row. To use the medicine, insert it directly into the vagina with the applicator provided.

Side Effects of Metronidazole

Many people take Metronidazole without difficulty, but it’s possible for this drug to cause certain side effects. Some are mild, while others can be more severe.

Call your doctor if any of the following common side effects get worse or don’t go away:

  • Headache
  • Diarrhea
  • Nausea
  • Vomiting
  • Stomach pain
  • Unusual or metallic taste in the mouth

If you exhibit any of the following more serious symptoms, contact a healthcare professional immediately:

  • Seizures
  • Hives or a rash
  • Itching
  • Blistering or peeling skin
  • Vaginal discharge, itching, or irritation
  • Tingling, burning, numbness, or pain in your hands or feet

Some of these side effects may be caused by other health conditions you have. Metronidazole may also make symptoms of other medical conditions worse. If you’re unsure why you have side effects, immediately talk to a doctor for medical advice.

Metronidazole and Yeast Infection

If you want to know, “Can Flagyl cause yeast infections?” the answer is yes. According to the National Institutes of Health (NIH), about 10% of women who take Metronidazole will develop a yeast infection. This happens because Metronidazole kills good and bad bacteria, including helpful vaginal flora that your body uses to keep infections in check. Other antibiotics can cause yeast infections, too, so it’s important that you only take them as prescribed by a doctor.

If you notice vaginal discharge after taking Metronidazole, you may have developed a yeast infection. This discharge may be clear and watery or thick and white with the texture of cottage cheese. Usually, the discharge has no odor. If your discharge has a strong fishy odor, you may have bacterial vaginosis and not a yeast infection, although it’s possible to have both infections simultaneously.

Yeast infection discharge can mimic STD discharge. Take a 10-panel STD test to ensure your yeast infection isn’t an STD.

Vaginal yeast infection symptoms to look for include:

  • Irritation and itching in the vulva
  • Vaginal pain and soreness
  • Rash around the vulva and vagina
  • Redness and swelling
  • Burning pain while urinating or having sexual intercourse

Metronidazole can cause oral yeast infections, such as thrush. Symptoms include:

  • Swollen tongue or a tongue that feels “furry”
  • Burning, redness, or soreness in the mouth
  • White lesions on the tongue, roof of the mouth, cheeks, and gums

Are you wondering, “Can I treat a yeast infection while taking Metronidazole?” You can, but taking Metronidazole with yeast infection medication can cause side effects. Ask your doctor before starting any treatment plan.

Most people can eliminate vaginal yeast infections with an over-the-counter treatment option. For oral yeast infections, try an antifungal mouthwash, such as nystatin. If your yeast infection is too severe to treat with over-the-counter medication, your doctor might prescribe you an oral dose of fluconazole to clear it up.

Precautions When Using Metronidazole

Metronidazole doesn’t mix well with some other medications. If you take any of the following, tell your doctor before using Metronidazole:

  • Phenobarbitone or phenytoin for epilepsy
  • Warfarin for blood clots
  • Disulfiram for alcohol abuse
  • Lithium for mental health conditions
  • Busulfan or fluorouracil for certain kinds of cancer
  • Ciclosporin for reduced immune response

Do not drink alcoholic beverages while taking Metronidazole, as this can cause severe side effects. You should also avoid taking any medications containing alcohol at the same time as Metronidazole.

Side effects of mixing Metronidazole with alcohol can include:

  • Stomach cramps
  • Nausea
  • Vomiting
  • Sweating
  • Headache
  • Redness of the face

Do not take more Metronidazole than prescribed, and avoid taking the drug if you aren’t using it to treat an active infection. Taking unnecessary antibiotics can cause yeast infections and make it more difficult to fight off infections in the future.

Some people may not be able to take Metronidazole. Tell your doctor if:

  • You have liver problems
  • You are undergoing dialysis
  • You are breastfeeding
  • You are pregnant or planning to become pregnant
  • You have ever had an allergic reaction to Metronidazole or any other antibiotic
  • You think you will be unable to stop drinking alcohol during your treatment plan
  • You are due to have your menstrual period, and your doctor prescribed you a vaginal cream

Questions To Ask Your Doctor

Before taking Metronidazole, ask your doctor these questions:

  • When will I feel better?
  • What should I do if my symptoms don’t improve or get worse?
  • Can I take Metronidazole with other medications I’m taking?
  • Can I drive while taking Metronidazole?
  • Will it affect my contraception?
  • Is there any food I need to avoid?
  • What should I do if I develop a vaginal yeast infection?
  • What if I develop an oral yeast infection or thrush?

Order Fast and Discreet STD Testing From Home

Now that we’ve answered the question, “Can Metronidazole cause yeast infections?” you might be wondering whether your itching and irritation are symptoms of an STD. Rapid STD Testing is here to help with same-day STD testing that you can order confidentially at home.

We offer testing for herpes, trichomoniasis, and other STDs that can mimic a yeast infection. You can visit one of 2,500 testing labs nationwide and get your results in one to two days. To order your test, visit Rapid STD Testing online or call us at (866) 872-1888 to find a lab near you.


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By: RSC Editorial Team
April 4, 2023

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