Your guide to the best antibiotics for UTIs in women

Key takeaways

• Urinary tract infections (UTIs) are caused by bacteria, most commonly E. coli, and antibiotics work by either killing the bacteria directly or stopping them from multiplying so your immune system can fight them off.
• Nitrofurantoin (Macrobid) is usually the first-choice antibiotic for uncomplicated UTIs in women, taken for 5 to 7 days. Other first-line options include sulfamethoxazole/trimethoprim (Bactrim) for 3 days or fosfomycin (Monurol) as a single dose.
• Your healthcare professional will choose the best antibiotic based on your health history, local resistance rates, treatment course length, and any medication allergies you may have.

Overview

Urinary tract infections (UTIs) are common, especially in women or people with vaginas, due to the way their anatomy is structured. Many uncomplicated UTIs go away on their own, but often, antibiotics are needed to fight the bacteria that cause the infection.

The right antibiotic for you depends on factors like your health history. Learn about first-line treatments like nitrofurantoin and trimethoprim-sulfamethoxazole, plus alternative options.

Note: Sex and gender exist on spectrums. This article uses the terms “women,” “men,” or both when discussing people assigned female or male at birth to reflect language that appears in source materials. 

While gender is solely about how you identify yourself, independent of your physical body, you may need to consider how your personal circumstances will affect diagnosis, symptoms, and treatment. 

Need a diagnosis or prescription for UTI? You can get discreet and expert on-demand care in as little as 15 minutes through Optum Perks. For $29, answer a few questions online and get a treatment plan from a US-licensed healthcare professional. Get started here.

How do antibiotics treat UTIs?

Most UTIs are caused by bacteria, most commonly E. coli. They happen when the bacteria from the bowel enter the urinary tract through the urethra and multiply.

Antibiotics are medications specifically developed to target bacteria. They work in two main ways:

• Bactericidal: Bactericidal antibiotics are those that directly kill the bacteria.
• Bacteriostatic: Bacteriostatic antibiotics stop the bacterial cells from multiplying, allowing your immune system to fight them off.

What to know about antibiotic resistance

Antibiotic resistance occurs when bacteria evolve to survive the drugs designed to kill them. When bacteria are exposed to an antibiotic but not completely wiped out, the “strongest” survivors can develop defenses, such as:

1. Pumps: Developing pumps that spit the antibiotic back out of the cell.
2. Armor: Changing their outer structure so the drug can’t latch on.
3. Enzymes: Producing chemicals that neutralize the antibiotic before it can work.

If a UTI or other bacterial infection is caused by resistant bacteria, standard treatments are more likely to fail. This can lead to longer illnesses, more expensive hospital stays, and the risk of the infection spreading to the kidneys or the bloodstream (sepsis).

This is why doctors will only prescribe antibiotics if absolutely necessary, and it’s important that you always finish the entire course of antibiotics, even if you feel better.

First-line antibiotics

When you take an antibiotic for a UTI, the medication travels through your bloodstream and is eventually filtered by your kidneys into your urine. This is why certain antibiotics are UTI-specific — they concentrate heavily in the bladder and urinary tract.

The first-line antibiotics for UTIs include:

Nitrofurantoin

Nitrofurantoin (Macrobid) is usually the first choice for treating uncomplicated UTIs in women. It’s a bacteriostatic antibiotic, and the usual treatment course is 5 to 7 days. Antibiotic resistance development is relatively uncommon with nitrofurantoin, which is why it’s a good first choice.

It’s important to note that nitrofurantoin may be less effective for men with UTIs.

Like any medication, nitrofurantoin may cause some side effects, including:

• gastrointestinal upset
• dizziness or drowsiness
• urine discoloration

Sulfamethoxazole/trimethoprim

Sulfamethoxazole/trimethoprim (Bactrim) is a combination medication that’s typically used for 3 days as mini-dose therapy. However, resistance rates to this drug are high in many areas.

Trimethoprim alone may also be used if a person is allergic to sulfamethoxazole.

This medication may also cause some side effects, including:

• nausea or vomiting
• diarrhea
• skin rashes
• sensitivity to sunlight

Fosfomycin

Fosfomycin (Monurol) is a single-dose therapy for uncomplicated UTIs. It may be used in areas with significant resistance to other antibiotics. A single dose of fosfomycin is comparable to a 7-day or 10-day course of other antibiotics.

Some common fosfomycin side effects include:

• nausea or vomiting
• diarrhea
• headaches
• vaginal yeast infections

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How to choose the best antibiotic

Typically, your doctor will decide the “best” antibiotic for you depending on your specific health history and resistance rates in your area. They weigh the effectiveness of the drug against its side effects and consider your preferences for the dosing schedule.

The following factors may go into choosing the best antibiotic:

• Treatment course: Nitrofurantoin has the longest treatment course, whereas fosfomycin is only given as a single dose.
• Risk of resistance: Nitrofurantoin has the lowest risk of antibiotic resistance, but rates may be different in your area.
• Side effects: If you know you experience severe side effects with a specific antibiotic, consider asking your doctor about other options.
• Allergies: If you have a sulfa allergy, your doctor will skip combination drugs like sulfamethoxazole/trimethoprim and may opt for trimethoprim alone or an entirely different class of medication.

Online care for UTIs

While many UTIs may clear up on their own, seeking the proper treatment can help reduce healing time and prevent serious complications.

Online care services, including Optum Perks Online Care, may make getting treatment easier. With these services, you can submit an online form answering a few questions about your symptoms, and a US-licensed healthcare professional will respond soon after to prescribe a treatment plan.

Summary

Antibiotics are the gold-standard treatment options for UTIs. They can fight against the bacteria causing the infection, either killing them or stopping them from multiplying.

Nitrofurantoin is the first-line medication for women with UTIs. However, there are other options. A doctor will decide which is the best antibiotic for you depending on your individual health history.

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Disclaimer: While Optum Perks strives for factual, comprehensive, and current information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses.