Blujepa vs. Bactrim: 7 Key Differences Between These UTI Antibiotics

When a urinary tract infection (UTI) strikes, it feels like relief can’t come fast enough. But the right antibiotic can help, and there are several prescription options available.

A healthcare professional may recommend Blujepa (gepotidacin) or Bactrim (sulfamethoxazole / trimethoprim) to treat a UTI, depending on the type you’re experiencing. While both are effective treatments, each has unique features that set them apart.

Below, we’ll talk about seven key differences between Blujepa versus Bactrim for UTIs.

1. Blujepa and Bactrim treat different types of UTIs and populations

Both Blujepa and Bactrim are used to treat uncomplicated UTIs — those that occur in the lower part of the urinary tract in healthy women who aren't pregnant. But Bactrim is approved for a broader population.

Blujepa treats uncomplicated UTIs in women and girls ages 12 years and older. They must also weigh at least 40 kg (88 lbs).

Bactrim can treat uncomplicated UTIs in adults and kids ages 2 months and older. In fact, Bactrim is considered a first-choice medication for treating uncomplicated UTIs. It can also treat complicated UTIs, which tend to have more serious symptoms, such as fever or kidney problems. This type of UTI is more likely for men, pregnant women, and people with weak immune systems.

Bactrim and Blujepa have other uses, too

In addition to UTIs, Bactrim is FDA approved to treat these infections:

• Otitis media (middle ear infection)

• Bronchitis

• Shigellosis (intestinal infection)

• Pneumocystis pneumonia (fungal lung infection)

• Traveler’s diarrhea

As of December 2025, Blujepa is also approved to treat uncomplicated urinary or genital gonorrhea in certain people ages 12 years and older.

EXPERT PICKS: WHAT TO READ NEXT

• An exciting new option: Pharmacists review the new antibiotic Blujepa (gepotidacin) for treating uncomplicated urinary tract infections (UTIs).

• Blujepa FAQs: Learn from pharmacists about how long it takes for Blujepa to work, along with answers to other top questions.

• Recommended treatments: Physicians describe some of the best antibiotics for UTIs.

• Real stories: Hear from real people about their experiences taking the antibiotic Bactrim (sulfamethoxazole / trimethoprim).

2. Blujepa and Bactrim work in different ways

Blujepa belongs to a new class of antibiotics called triazaacenaphthylenes. It works in a unique way to block two topoisomerase enzymes (proteins), offering protection against a variety of bacteria that cause UTIs. This may also help prevent antibiotic resistance.

Bactrim has two active ingredients, sulfamethoxazole and trimethoprim. They work as a team to block bacteria from making folic acid. Without folic acid, bacteria can’t grow and survive.

Unfortunately, certain UTIs are resistant to Bactrim. Studies show about a quarter of UTIs caused by E. coli, a frequent UTI bacteria culprit, are resistant to Bactrim. That’s why new antibiotics like Blujepa are important options to have for treating UTIs.

3. Bactrim comes in more formulations

Blujepa is a brand-name medication that’s supplied as a 750 mg tablet. Bactrim, by comparison, has more formulation flexibility.

You can find Bactrim as both a brand-name and generic medication. It comes in two main tablet doses:

• Bactrim DS (double strength): Sulfamethoxazole 800 mg / trimethoprim 160 mg

• Bactrim SS (single strength): Sulfamethoxazole 400 mg / trimethoprim 80 mg

Bactrim is available in other forms, too:

• Oral liquid suspension: Sold as Sulfatrim Pediatric, each 5 mL (teaspoonful) contains sulfamethoxazole 200 mg and trimethoprim 40 mg. This option is useful for children or anyone who has trouble swallowing pills.

• IV (intravenous) injection: You can receive Bactrim as an IV in the hospital.

Good to know: Before taking Sulfatrim Pediatric, it’s important to shake it well. This ensures you get the right amount of medication in each dose.

4. Blujepa and Bactrim have different dosage schedules for UTIs

Blujepa and Bactrim have different dosages for treating UTIs. The recommended Blujepa dosage is 2 tablets (1,500 mg total) by mouth twice daily for 5 days. It’s best to separate each dose by about 12 hours. Taking Blujepa shortly after a meal helps prevent an upset stomach.

The typical Bactrim DS dosage for adults is 1 tablet by mouth twice a day for 3 to 14 days. If you’re prescribed Bactrim SS, the dosage is 2 tablets by mouth twice a day. Just like with Blujepa, taking Bactrim with food may help lower the chances of stomach-related side effects. 

If your child has a UTI, their pediatrician will decide the appropriate Bactrim dosage based on their body weight. 

Dosage adjustment for kidney problems

If you have impaired kidney function, Bactrim can build up in your body. This can also raise the risk of side effects.

One way to determine how well your kidneys are working is by looking at your creatinine clearance (CrCl). A healthcare professional can estimate this from lab tests. If your CrCl is very low, it means you have relatively substantial kidney problems. In this situation, your prescriber will likely recommend taking half of the recommended dose of Bactrim.

Similarly, people with serious kidney problems should avoid taking Blujepa. This is also true for those with severe liver problems.

5. Bactrim is a sulfa drug, while Blujepa is not

The sulfamethoxazole portion of Bactrim contains a chemical called sulfonamide. Bactrim is commonly referred to as a “sulfa drug” for this reason. You should avoid taking Bactrim if you have a sulfa allergy. Blujepa, though, is not a sulfa drug. It might be an alternative to Bactrim if you have a sulfa allergy.

But what happens if you experience a sulfa allergy? Skin rashes, hives, and fever are a few common symptoms to watch out for. They typically appear within the first 1 to 2 weeks of starting Bactrim.

Although uncommon, both Bactrim and Blujepa can cause serious allergic reactions. Anaphylaxis is a potentially life-threatening reaction if left untreated. Swelling of the face, lips, and tongue, along with trouble breathing are a few hallmark symptoms of anaphylaxis. Seek emergency medical care right away if you experience any of these symptoms.

If you have a sulfa allergy, make sure to let your healthcare team know. They most likely won’t recommend Bactrim to treat your UTI.

6. Blujepa and Bactrim side effects look slightly different

Blujepa and Bactrim share certain side effects. But they also have unique ones that set them apart. We compare Blujepa versus Bactrim side effects in the table below.

Serious side effects

While rare, both Blujepa and Bactrim can also cause serious side effects that are important to be aware of. If you experience any of the symptoms below, reach out to a healthcare professional right away. If your symptoms feel severe, listen to your body and call 911 or go to the nearest ER.

Serious Blujepa side effects may include:

• Change in the heart’s electrical system, which can lead to life-threatening abnormal heart rhythms

• Clostridioides difficile (C. diff) diarrhea

• Cholinergic effects, such as muscle spasms and slurred speech

Serious Bactrim side effects may include:

• Stevens-Johnson syndrome (serious skin reaction)

• Hypoglycemia (low blood sugar)

• C. diff diarrhea

• Sodium and potassium electrolyte changes

• Kidney problems

• Thrombocytopenia (low platelet levels)

7. Both medications have several interactions to consider

Certain medications, foods, and supplements can interact with both Blujepa and Bactrim. Many interactions should be avoided altogether, while others may be managed with a quick dose adjustment or extra monitoring by your prescriber. Your prescriber and pharmacist can help you manage any potential interactions.

Here are some notable interactions to keep in mind:

This isn’t a complete list of interactions. It’s a good idea to keep a current list of your prescription and over-the-counter (OTC) medications handy. Your pharmacist and prescriber should screen for interactions with Blujepa or Bactrim before starting treatment with either one.

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Written by:

Jennifer Gershman, PharmD, CPh, PACS

Jennifer Gershman, PharmD, is a licensed pharmacist in Florida. She has worked in the pharmacy industry for more than 15 years and is currently a medical writer.

Edited by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Reviewed by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

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