What Are the Most Common Antibiotics for UTIs?

Posted by AweSamo March 5, 2026
What Are the Most Common Antibiotics for UTIs?

Key Takeaways

  • Nitrofurantoin is a good first-line option for UTIs because there is minimal bacterial resistance.
  • Bactrim is effective but is only used when bacterial resistance is below 20%.
  • Fosfomycin is a single-dose option but may be less effective than other treatments.

Urinary tract infections (UTIs) are bacterial infections of the urinary tract. The most common type of UTI is cystitis which occurs in the lower portion of the urinary tract when bacteria enter the urethra and travel to the bladder.

As the bacteria multiply in the urinary tract, they cause symptoms such as pain with urination, feeling like you need to urinate more frequently, feeling the need to urinate even if you’ve just emptied your bladder, and blood in the urine. 

If you are diagnosed with a UTI, your healthcare provider will prescribe antibiotics. Antibiotics commonly recommended to treat UTIs are Macrobid (nitrofurantoin), Bactrim (trimethoprim/sulfamethoxazole), and fosfomycin.

Fluoroquinolones like ciprofloxacin are no longer routinely recommended due to their side effects and increasing bacterial resistance.

Jacob Wackerhausen / Getty Images


Commonly Used Antibiotics for Urinary Tract Infections

UTIs are caused by bacteria and are typically treated with antibiotics, which may include:

  • Macrobid, Macrodantin (nitrofurantoin)
  • Bactrim, Bactrim DS (trimethoprim/sulfamethoxazole)
  • Fosfomycin
  • Fluoroquinolones, such as ofloxacin, ciprofloxacin, or levofloxacin (only if other options are not suitable)
  • Blujepa (gepotidacin)

Macrobid/Macrodantin

Macrobid and Macrodantin (nitrofurantoin) are effective against most bacteria that commonly cause UTIs. There is minimal bacterial resistance to nitrofurantoin, making it a good first-line option.

If prescribed nitrofurantoin, you will typically take it for five days. 

Bactrim

Bactrim (trimethoprim/sulfamethoxazole) is a combination of two antibiotics.

While it can effectively treat UTIs, in recent years, bacterial resistance has increased. This medication is generally used in areas where the resistance rate is below 20%. If you’re allergic to sulfa drugs, you should not take this antibiotic. Typically, if prescribed, the course lasts three days.

Fosfomycin

Fosfomycin is another suitable antibiotic option for UTIs due to minimal bacterial resistance. However, it appears to be less effective than other standard short-course treatments.

The treatment course is just a single dose, making it a convenient option. It comes as a powder that needs to be mixed with a half-cup (3 to 4 ounces) of cool water before drinking. You do not need to take it with food.

Fluoroquinolones

Fluoroquinolones are a class of antibiotics that include ciprofloxacin, ofloxacin, and levofloxacin.

These medications should be used only if other options are not suitable. Increasing bacterial resistance to fluoroquinolones has made this class of antibiotics less useful for UTI treatment in recent years.

Blujepa

Blujepa (gepotidacin) is the first drug approved in a new class of antibiotics known as triazaacenaphthylene, which works differently from other antibiotics and has a lower potential for antibiotic resistance. If prescribed Blujepa, you will typically take it for five days.

Complicated vs. Uncomplicated UTIs

A UTI is classified as uncomplicated when it occurs in people who are premenopausal, nonpregnant, and without urological abnormalities or co-existing health conditions. The antibiotics covered in this article apply to treating uncomplicated UTIs.

Complicated UTIs may be caused by different types of bacteria with different resistance patterns, so antibiotic treatment requires a different approach.

How Do Antibiotics Treat UTIs?

Antibiotics taken by mouth work to treat bacterial UTIs through the following steps:

  1. The antibiotic is absorbed in the gastrointestinal tract and enters the bloodstream.
  2. It travels in the bloodstream to the kidneys, where it is delivered to the urinary tract.
  3. The drug is then filtered into the urine.
  4. As the urine enters the bladder, it comes into contact with and kills the bacteria causing the infection.

Side Effects of Antibiotics

Antibiotics prescribed for UTIs can cause side effects, similar to most antibiotics. Common side effects include nausea and an upset stomach, which may occur with any of the three antibiotics often used for UTIs.

Additional common side effects include:

Nitrofurantoin

  • Loss of appetite
  • Headache
  • Flatulence

Trimethoprim/sulfamethoxazole

  • Loss of appetite
  • Skin rash or redness

Fosfomycin

  • Diarrhea
  • Headache
  • Backache
  • Vaginitis
  • Stuffy nose

Blujepa

  • Diarrhea
  • Nasuea
  • Stomach pain
  • Headache
  • Gas

Most side effects are mild and temporary while taking antibiotics. If you experience side effects that are severe enough to consider stopping treatment, contact a healthcare provider to see if an alternative antibiotic needs to be substituted to complete therapy.

How Long Do Antibiotics Take to Treat a UTI?

Symptoms of a UTI improve rapidly after starting antibiotics, usually within a few hours. Do not stop taking antibiotics once you start to feel better, and do not save antibiotics to use later.

It can take several days to clear the infection fully, so it is important to finish the entire course of antibiotics prescribed (usually three to five days).

Contact your healthcare provider for reevaluation if you notice no improvement in symptoms after starting antibiotics or if symptoms worsen.

Preventing Antibiotic Resistance

Antibiotics work to treat an infection by killing the bacteria causing the infection. Once you start antibiotics, you should start feeling better in the first day or two. This is because the antibiotic kills bacteria and decreases your body’s inflammatory response to infection.

Even though you feel better, it’s important to keep taking the antibiotics until you finish the entire course. It takes time to kill all of the bacteria causing infection. Stopping antibiotics too early could cause the infection to return and lead to bacteria developing antibiotic resistance.

Resistance occurs when bacteria are exposed to an antibiotic but not completely killed. The remaining bacteria can develop a mutation that helps them survive, leading to bacteria that are harder to treat in the future.

Are There Over-the-Counter Remedies for UTIs?

There are no over-the-counter (OTC) treatments to cure a UTI, though some OTC products can help temporarily relieve the symptoms.

AZO (phenazopyridine) is a bladder anesthetic that temporarily relieves symptoms of burning, pain, urgency, and frequency but does not treat the bacterial infection.

You should always see a healthcare provider if you suspect a UTI. An untreated infection can progress up the urinary tract to evolve into a more severe infection of the kidneys (pyelonephritis). 

Frequently Asked Questions

  • How will my healthcare provider decide which antibiotic to prescribe for a UTI?

    Your healthcare provider will typically choose an antibiotic for a UTI based on empirical treatment. This involves using their best guess to target common bacteria and considering local antibiotic resistance patterns. They will also review your specific details, such as allergies. A urine culture might be collected to see if a different antibiotic is needed, but it takes one to two days, so it doesn’t guide the initial choice.

  • What is the strongest antibiotic for a UTI?

    The strongest antibiotic for a UTI effectively targets the infection while sparing healthy bacteria. Common antibiotics successfully eliminate bacteria in urine.

  • Can I take antibiotics for my UTI while pregnant?

    Yes, though the choice of antibiotic may differ for non-pregnant people.

  • Do I need to take an antibiotic to get rid of a UTI?

    Yes, clearing a bacterial UTI requires antibiotics. If symptoms continue after treatment, contact your healthcare provider, as non-infectious issues, like irritants, may be involved.

  • What happens if my UTI returns after antibiotic treatment?

    If symptoms come back after antibiotic treatment, consult your healthcare provider. They’ll likely do a urine culture to check for ongoing infection or whether you need a different antibiotic.


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