If you’ve ever been prescribed the antibiotic metronidazole for a vaginal infection and found it really effective, you may be wondering: does metronidazole treat UTIs, too? Maybe you’re dealing with bacterial vaginosis (BV) and a urinary tract infection (UTI) at the same time, and are hoping to kill two birds with one stone. 

The thing is, antibiotics can be incredibly effective in treating infections, but it all comes down to what bacteria is stirring up trouble. And there are millions and millions of different bacteria living in your vaginal and urinary microbiomes. 

Keep scrolling to learn more about metronidazole and the best way to treat UTIs. 

What is a UTI?

A UTI is a common infection that occurs in any part of your urinary system, which includes your kidneys, bladder, ureters, and urethra. Most infections involve the lower urinary tract, which comprises the bladder and the urethra. UTIs are particularly common in women due to the shorter length of the urethra, which allows bacteria easier access to the bladder.

Here’s how bacteria can find their way into your urinary tract:

If you've ever had a UTI, you know it can be uncomfortable and disruptive. Here are some common symptoms to watch out for:

  • A burning sensation when you pee
  • Frequent urination
  • Feeling like you can’t fully empty your bladder
  • Urine that appears red, bright pink, or brown
  • Pelvic pain
  • Flu-like symptoms. 
Recurrent symptoms? Meet Evvy's at-home vaginal microbiome test, approved by leading OB-GYNs.
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What is metronidazole?

Metronidazole is an antibiotic commonly used to treat bacterial infections and parasitic infections, like BV, and a sexually transmitted infection (STI) called trichomoniasis, respectively. 

Metronidazole is particularly effective at killing anaerobic bacteria (bacteria that don’t need oxygen to survive). It’s been tested and found to be effective against several bacterial species that are associated with bacterial vaginosis, including: 

Metronidazole works by entering bacterial cells and interfering with their DNA synthesis. This prevents the bacteria from multiplying and spreading, ultimately killing the infection. 

Does metronidazole treat UTIs?

Despite its effectiveness against many types of bacterial infections — including some vaginal infections — metronidazole isn’t typically used to treat UTIs. 

UTIs are most often caused by aerobic bacteria such as Escherichia coli (E. coli), which aren’t the primary targets of metronidazole. Plus, most metronidazole is available in the form of a vaginal gel or capsules. Vaginally applied antibiotics are unlikely to reach the bladder in sufficient concentrations to combat uropathogens like E. coli.

It’s important to remember that antibiotics are only effective if you’re taking them for the specific bacteria they’re designed to kill. That’s why testing your vaginal microbiome can be a helpful tool in finding the right antibiotic treatment for you. Evvy’s Vaginal Health Test uncovers over 700 bacteria and fungi present in your vaginal microbiome, including ones responsible for UTIs, such as E. coli, Staphylococcus and Aerococcus. Evvy’s Expanded PRC Panel also tests for 11 types of antibiotic resistance, including ones related to UTIs. 

How to treat a UTI

If you suspect you have a UTI, it's essential to see a healthcare provider for an accurate diagnosis and appropriate treatment. 

If you've been diagnosed with a UTI, your doctor will prescribe antibiotics best suited to treat the bacteria causing your infection. The choice of antibiotic will be based on factors like your medical history, allergies, the type of UTI you have, and whether you suffer from recurrent UTIs.

Antibiotics like trimethoprim-sulfamethoxazole (Bactrim), nitrofurantoin (Macrobid), or ciprofloxacin (Cipro) are usually prescribed to treat UTIs because they are more effective against the bacteria commonly responsible for these infections. 

On top of antibiotic treatments, there are a few measures you can take to speed treatment along and relieve any uncomfortable symptoms: 

  • Heat therapy: Applying a heating pad to your belly can help reduce bladder pressure and discomfort.
  • Avoid irritants: Cut back on caffeine, alcohol, spicy foods, and artificial sweeteners, which can irritate your bladder. Just until your UTI clears up!
  • Hydration: Drink plenty of water to help flush bacteria from your urinary system.
  • Pain relief: Over-the-counter pain relievers like ibuprofen can help alleviate discomfort.
  • Pee frequently: Don't hold in urine! Go to the bathroom as soon as you feel the urge to pee.

When to see a healthcare provider

It’s important to get UTIs treated early so they don't progress to more severe symptoms. It's crucial to consult a healthcare provider if you experience severe symptoms like a high fever, chills, back or side pain, or vomiting. 

If your symptoms persist or worsen after finishing your course of antibiotics, you may need a different treatment.

FAQ

Can metronidazole treat urinary tract infections? 

No, metronidazole isn’t typically used for treating UTIs. That’s because metronidazole doesn’t target the bacteria commonly responsible for causing UTIs. First-line treatment options for UTIs include nitrofurantoin, fosfomycin, and sulfamethoxazole-trimethoprim.

What infection does metronidazole treat?

Metronidazole is a commonly prescribed antibiotic used to treat a wide range of infections caused by certain bacteria and parasites — from mouth and skin infections to bacterial vaginosis, pelvic inflammatory disease (PID), and trichomoniasis.

What is the best antibiotic for UTIs?

Finding the best antibiotic for treating a urinary tract infection depends on a few things, like the exact bacteria causing the infection and your medical history. Commonly prescribed antibiotics for uncomplicated UTIs include trimethoprim-sulfamethoxazole (Bactrim), nitrofurantoin (Macrobid), and fosfomycin (Monurol). These antibiotics are generally good at fighting the most common UTI-causing bacteria, like E. coli. It's really important to talk to a healthcare provider for a proper diagnosis and to make sure the antibiotic chosen is right for your case. And remember to finish the full course of antibiotics as prescribed to fully get rid of the infection and prevent resistance.