Can you take fluconazole and metronidazole together?

In this article:

• Can you take metronidazole and fluconazole together?
• How to take fluconazole with metronidazole
• Considerations when taking fluconazole and metronidazole
• Is fluconazole or metronidazole better?
• Fluconazole vs. metronidazole: Comparison chart
• Bottom line

In this article

• Can you take metronidazole and fluconazole together?
• How to take fluconazole with metronidazole
• Considerations when taking fluconazole and metronidazole
• Is fluconazole or metronidazole better?
• Fluconazole vs. metronidazole: Comparison chart
• Bottom line

Fluconazole is a prescription antifungal medication. It is approved by the Food and Drug Administration (FDA) to treat types of various fungal infections, such as vaginal yeast infections—where it is commonly taken as either a single dose or repeated doses. It can also be used to treat yeast infections of the mouth, throat, blood, esophagus, stomach, lungs, and other organs. Fluconazole is often referred to by the brand name Diflucan. It works by slowing the growth of yeast.

Metronidazole is a prescription medication classified as a nitroimidazole antimicrobial. It is FDA approved to treat various types of infections, including bacterial vaginosis, certain sexually transmitted diseases (STDs), and infections of the reproductive system, gastrointestinal tract, skin, joints, heart, bones, lungs, and blood. Metronidazole is commonly referred to by the brand name Flagyl, and it works by stopping bacteria from growing.

While each medication treats different types of infections, there are situations when your healthcare provider may prescribe fluconazole and metronidazole together. This article will explain whether it is safe to combine these drugs, as well as other important information and considerations regarding fluconazole and metronidazole.

Can you take metronidazole and fluconazole together?

Yes, in most cases, it is safe to take fluconazole and metronidazole together. For example, up to 30% of women with a type of bacterial infection called bacterial vaginosis (BV) also have a Candida infection (a type of yeast infection) and may be prescribed both medicines. 

However, according to the Prescribers’ Digital Reference (PDR), taking fluconazole and metronidazole together may increase the risk of heart rhythm problems. This includes a serious medical condition called torsade de pointes, which is a type of abnormal heart rhythm known as ventricular tachycardia. If your healthcare provider thinks you may be at risk for heart rhythm problems, they may try to avoid this combination of medications. Or, if the combination cannot be avoided, they will monitor you closely during treatment. People with risk factors for torsades de pointes should talk with their healthcare provider about the risks and benefits of taking fluconazole and metronidazole together. Risk factors for torsade de pointes include:

• Having a medical condition called long QT syndrome
• Having heart disease
• Being female
• Being 65 or older
• Taking a diuretic (water pill)
• Having a very slow heart rate
• Having low levels of electrolytes such as calcium, magnesium, or potassium
• Having severe vomiting and diarrhea

How to take fluconazole with metronidazole

The most important thing to do when determining whether you can take fluconazole and metronidazole together is to consult a healthcare provider for medical advice. Even if you have been prescribed each drug separately on different occasions, it is still important to consult a healthcare provider for a diagnosis and appropriate treatment. 

If your healthcare provider determines it is safe for you to take fluconazole and metronidazole together, there is still a possibility that one or both drugs may interact with another medicine you take. It is important to tell your healthcare professional about all of your medical conditions—including if you are pregnant or breastfeeding, as well as all of the medications you take, including prescription drugs, over-the-counter (OTC) medications, vitamins, and supplements.

One situation where you may be prescribed both fluconazole and metronidazole is to prevent BV in cases where you get frequent or recurring infections. In this case, you may be prescribed a dose of 2,000 mg of metronidazole once a month, along with fluconazole 150 mg. This combination may help reduce the incidence of BV infection and promote the growth of healthy bacteria in the vagina. 

If your healthcare provider prescribes both drugs together, you’ll want to know how to take each medication. Follow the instructions on your medication label, and check with your healthcare provider or pharmacist if you have any questions or concerns. Here are some things to be aware of for each medication:  

Is fluconazole or metronidazole better?

While these two medications are sometimes prescribed at the same time, they work differently and have different uses. You may have BV and also a yeast infection at the same time—but metronidazole will treat the BV while fluconazole will treat the yeast infection. Therefore, we can’t really compare which one is better because they are not meant to treat the same conditions. Always check with your healthcare provider for medical advice, as there are many factors to consider when determining if a drug or combination of drugs is safe for you to take. 

The table below provides some information about both drugs, including their drug class, forms, risks and restrictions, and side effects. 

Bottom line

In many cases, fluconazole and metronidazole are safe to take together, as long as you are under the guidance of a healthcare provider. People who are at risk for heart rhythm problems, such as those with long QT syndrome, heart disease, or electrolyte imbalances, may need to avoid this combination of drugs. If the combination cannot be avoided, close monitoring will be required. Always take your medication as directed by your healthcare provider, and check with them if you have any questions or concerns.