Taking certain antibiotics may lead to a yeast infection in the vagina, also known as a fungal infection or vaginal candidiasis.

A yeast infection is a form of vaginitis, which means inflammation in the vagina. Vaginitis is the most common vaginal condition in people aged 15–44.

Vaginal candidiasis, caused by Candida fungus, is the second most common type of vaginal infection in the United States, after bacterial infections.

This article examines how taking antibiotics can sometimes lead to yeast infections. It also describes which antibiotics can cause these infections and how to treat them.

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

A yeast infection occurs when something upsets the delicate balance of bacteria and yeast in the vagina.

A small amount of Candida fungus is usually present in the vagina, and beneficial bacteria help keep this fungus under control.

Antibiotics work by killing bacteria that cause infection, but they can also kill beneficial bacteria in other parts of the body, including the vagina.

Without enough beneficial bacteria to keep the yeast at bay, Candida yeast can multiply, causing the symptoms of a yeast infection.

Some people are more prone to yeast infections than others. According to current estimates, 8% of females have recurring Candida infections, and around 70% of females report dealing with this condition at least once in their lifetime.

Yeast infections can develop at any age, but these infections are more common during reproductive years.

The common symptoms of a vaginal yeast infection tend to be more noticeable just before menstruation. A person may experience:

These symptoms are mild in most cases. In severe infections, redness, swelling, or cracks form in the walls of the vagina.

It can be difficult to distinguish between a yeast infection and a urinary tract infection (UTI). Learn to tell the difference here.

Not all antibiotics are likely to cause yeast infections — only broad-spectrum antibiotics tend to have this effect. These drugs can kill several different types of bacteria.

The following three types of broad-spectrum antibiotic, in particular, may increase the risk of a yeast infection:

Tetracyclines

Doctors prescribe tetracyclines for acne, UTIs, intestinal tract infections, eye infections, sexually transmitted infections, and gum disease.

Examples of tetracyclines and common brand names include:

  • demeclocycline (Detravis)
  • doxycycline (Adoxa)
  • eravacycline (Xerava)
  • minocycline (Minocin)
  • omadacycline (Nuzyra)
  • tetracycline (Sumycin)

Quinolones

Doctors prescribe quinolones for difficult-to-treat UTIs, hospital-acquired pneumonia, and bacterial prostatitis. Common examples include:

Broad-spectrum penicillins

Broad-spectrum penicillins, such as ampicillin and amoxicillin, may also lead to yeast infections.

Yeast infections are common, but a few circumstances may make it more likely a person will develop one. These circumstances include:

  • pregnancy
  • hormone contraceptive use, such as birth control pills
  • diabetes
  • a weakened immune system due to factors such as chemotherapy treatment or HIV infection

If a person is living with one of these risk factors, they should talk with their doctor if they have been prescribed antibiotics, as there can be an increased risk of yeast infection.

While yeast infections are more common among sexually active people, there is no evidence that they are sexually transmitted.

Treating a yeast infection is usually a straightforward process. In most cases, a person will either apply a cream or ointment to the inside of the vagina or take a pill containing an antifungal medicine, such as fluconazole or miconazole.

A doctor can prescribe antifungal creams or tablets. People can also find over-the-counter (OTC) antifungal vaginal creams at drugstores, or online.

Some infections, such as recurring chronic infections, may require stronger treatment. In this case, a doctor may recommend additional doses of fluconazole or creams that contain boric acid, nystatin, or flucytosine.

The Centers for Disease Control and Prevention (CDC) recommend that anyone who suspects they have vaginal candidiasis speak with a healthcare professional. This is because the symptoms are similar to those of other vaginal infections, which require different treatments.

A healthcare professional can ensure that a person gets the right medication for the infection. To identify vaginal candidiasis, they usually take a small sample of vaginal discharge for examination under a microscope.

Pregnancy and fluconazole

Pregnant people may want to avoid treating yeast infections with fluconazole due to the risk of birth abnormalities. According to an older safety announcement from the Food and Drug Administration (FDA), a single 150-microgram dose of fluconazole may not cause this effect, but taking it for longer periods or at a higher dosage carries this risk.

While a 2013 study did not find a significantly increased risk of birth abnormalities when pregnant people took fluconazole, a more recent cohort study from 2020 did find an association with fluconazole use during the first trimester and musculoskeletal malformations.

Pregnant individuals managing a yeast infection should discuss with their doctor about the risks of fluconazole, and other alternative treatments.

People can help prevent vaginal candidiasis by taking antibiotics only when they are necessary. It is worth remembering that antibiotics do not work on viral infections, such as a cold or the flu.

Antibiotics also do not work on some common bacterial infections, such as many types of bronchitis, sinus infections, and ear infections. A person should always speak with a healthcare professional before starting a course of antibiotics.

A few other ways to help prevent yeast infections include:

  • wearing cotton undergarments
  • avoiding feminine hygiene sprays
  • avoiding scented tampons
  • avoiding harsh soaps when cleaning the vagina
  • using condoms during sex

In addition, there is some evidence that eating yogurt that contains live cultures every day or taking Lactobacillus acidophilus capsules may help prevent these infections.

While little high quality research has investigated this use of probiotics, many healthcare professionals recommend taking a probiotic supplement either during or immediately after completing a course of antibiotics to reduce the risk of a yeast infection.

Some types of antibiotics can lead to a vaginal yeast infection, which is a form of vaginitis known as vaginal candidiasis.

Antibiotics kill bacteria, which can upset the delicate balance of yeast and bacteria in the vagina. This allows the Candida fungus to multiply, leading to symptoms such as itching, burning, or pain during sex.

It is usually straightforward to treat yeast infections with OTC antifungal medications. However, anyone who suspects that they have this type of infection should consult a doctor to rule out other issues with similar symptoms.