If you’re healthy, your urinary tract is anatomically and functionally normal, and you aren’t unusually vulnerable to UTIs, your UTI is considered uncomplicated, or simple. These infections are typically treated with a short course of oral antibiotics.
Other UTIs, including those in elderly and pregnant patients, are considered complicated. With a complicated UTI, you may get intravenous (IV) antibiotics or a longer oral antibiotic course.
UTI symptoms typically subside after a few doses of an antibiotic. However, it’s important to always complete the entire course of antibiotics as directed by your healthcare provider even if you’re feeling better. If the infection isn’t completely cleared, your symptoms will likely return.
Antibiotic resistance is also a growing concern when treating UTIs.
These are the most common types of antibiotics used to treat UTIs.
Nitrofurantoin
Nitrofurantoin is a first-line treatment for uncomplicated UTIs, and is taken for five to seven days. It may also be prescribed for some complicated UTIs, and as a preventive treatment for recurrent UTIs. Because of its potential fetal effects, nitrofurantoin is only used during pregnancy under certain circumstances.
Nitrofurantoin doesn’t usually cause serious side effects, but you may experience nausea, vomiting, or diarrhea.
Trimethoprim-Sulfamethoxazole
This is a combination of two antibiotics called sulfonamides. It’s also known as co-trimoxazole or TMP-SMX. Brand names include Bactrim and Septra.
TMP-SMX is another first-line treatment for uncomplicated UTIs, and can be used preventively. It’s typically prescribed for five to seven days of treatment. Because of potential effects on a fetus, it’s usually only prescribed in certain cases for pregnant women.
Fosfomycin
This one-dose UTI antibiotic treatment is a first-line treatment for uncomplicated UTIs and is also considered a safe choice during pregnancy.
Fosfomycin doesn’t usually cause serious side effects, but you may experience nausea or diarrhea.
Penicillins
These antibiotics, in the beta-lactam class, generally aren’t used to treat uncomplicated UTIs because of high rates of drug resistance, but there are exceptions. They may also be used as an IV treatment for complicated UTIs. These drugs have lower clinical and bacterial cure rates than first-line treatments.
Penicillins available to treat UTIs include:
- Pivmecillinam (Pivya) is approved to treat uncomplicated UTIs caused by E. coli, Klebsiella pneumoniae, or Proteus mirabilis bacteria. Pivmecillinam is taken for three to seven days.
- Amoxicillin-clavulanate (Augmentin ES) combines a penicillin antibiotic with a drug to prevent resistance. It may be used to treat an uncomplicated UTI if a urine culture shows it’s the most effective drug.
- Ampicillin-sulbactam (Unasyn) is a combination drug that may be given intravenously for a complicated UTI.
Penicillins are usually well tolerated, although some people can have an allergic reaction and develop a rash.
Cephalosporins
These beta-lactam antibiotics are considered a second-line treatment for uncomplicated UTIs, usually taken for five to seven days. They may also be administered by IV or injection to treat complicated UTIs, including severe infections that are resistant to other antibiotics. They include:
- cefdinir
- cefepime
- cefiderocol (Fetroja)
- cefpodoxime
- ceftazidime-avibactam (Avycaz)
- ceftolozane-tazobactam (Zerbaxa)
- ceftriaxone
- cephalexin (Keflex)
Cephalexin has been shown to be safe for pregnant women and can be used as a preventive treatment for recurrent UTIs.
Cephalosporins don’t usually cause serious side effects, although you may experience nausea and vomiting. If you’ve had an allergic reaction to a penicillin or other beta-lactam drug, you should not take them.
Fluoroquinolones
These antibiotics are considered highly effective for UTI treatment. However, they can have serious side effects. For uncomplicated UTIs, experts say fluoroquinolones should only be used in patients who have no other treatment options.
The following are recommended for treating complicated UTIs:
Some of the side effects of fluoroquinolones can be serious. They include damage to your tendons, muscles, joints, and nerves. These drugs can cause extremely low blood sugar, which can lead to coma, and mental health side effects like agitation and trouble concentrating.
Carbapenems
Another type of beta-lactam antibiotic, carbapenems are often considered a drug of last resort. They are used to treat complicated UTIs caused by drug-resistant bacteria, and may be paired with a drug that fights the germ’s resistance mechanisms. These drugs are administered by IV and include:
Common side effects include nausea and vomiting. It’s rare, but these drugs can cause seizures at high doses, especially imipenem.
Sulopenem Etzadroxil–Probenecid
The combination drug (Orlynvah) received FDA approval in 2024 to treat uncomplicated UTIs caused by E. coli, Klebsiella pneumoniae, or Proteus mirabilis in women who can’t take other antibiotics. It’s a beta-lactam antibiotic that’s taken for five days.
Potential side effects include nausea, vomiting, diarrhea, and vaginal yeast infections. It can lead to C. diff diarrhea, and shouldn’t be used if you have gout or kidney stones.
Aminoglycosides
Antibiotics in this class, particularly gentamicin, may be combined with other drugs in the IV treatment of complicated UTIs. Another aminoglycoside, plazomicin (Zemdri) is designed to be used against drug-resistant bacteria and is approved for people who have few or no other options.
These drugs can cause hearing loss and kidney damage.
Gepotidacin
Gepotidacin (Blujepa) became FDA-approved for UTI treatment in 2025. It’s approved for use in female adults and pediatric patients ages 12 and older.
Gepotidacin is an oral antibiotic with similar effectiveness to other UTI treatments, but shows a low potential for resistance. It’s a promising oral treatment option for drug-resistant infections.
It’s taken for five days and studies suggest it’s well tolerated. Mild to moderate side effects include diarrhea and nausea.
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