Key takeaways
- Nitrofurantoin is an antibiotic that typically begins to alleviate UTI symptoms within a few days, though it is important to complete the entire prescribed course to prevent the infection from returning.
- The duration of nitrofurantoin treatment for a UTI varies, with uncomplicated cases usually requiring about 5 days of medication, while more severe or complicated infections may need 10 to 14 days.
- Nitrofurantoin works by slowing and stopping bacterial growth, and despite being an older antibiotic, it remains an effective treatment for uncomplicated UTIs, comparable to newer alternatives.
Overview
Bacteria that get into your urethra can cause a urinary tract infection (UTI). Doctors treat certain bacterial infections, like a UTI, with antibiotics, such as nitrofurantoin.
Nitrofurantoin is a generic drug that comes as an oral capsule and in a liquid form. The oral capsules are available as the brand-name drug Macrobid. The brand-name version of the liquid form is Furadantin.
You can typically expect to feel better within a few days of taking nitrofurantoin. You need to finish the entire course of this medication, even if you feel better. If you stop taking it too soon, the infection may come back again.
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How many days does it take for nitrofurantoin to work?
Nitrofurantoin should start to work within a few days after you start taking it. Even if you start to feel better, be sure to continue taking nitrofurantoin until your prescription is complete.
If you have an uncomplicated UTI, your treatment course will typically be around 5 days. An uncomplicated UTI usually affects the lower urinary tract and is less likely to lead to serious complications.
A complicated UTI might require a longer course of antibiotics of about 10 to 14 days. But you should be able to notice if you’re responding to treatment for a complicated UTI within 24 to 48 hours.
A complicated UTI affects the upper urinary tract, such as the kidneys, and can cause more severe symptoms and complications. These types of UTIs may be harder to treat.
To help speed up healing from a UTI, try to:
- drink plenty of water
- urinate often and fully empty your bladder
- use a heating pad to manage back or abdominal pain
If your symptoms don’t get better within a few days or worsen, tell your doctor right away. They may prescribe a different antibiotic medication that has broader bacterial coverage.
Medical perspective
Why is it important to complete the full course of antibiotics, even if you feel better?
“It is important to finish the full course of antibiotics, even if you feel better, to completely get rid of the infection and reduce the risk of it coming back.”
Note: Quotes represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
What is the typical dosage of nitrofurantoin for a UTI in adults?
For treating a UTI, the recommended dosage of nitrofurantoin depends on the form prescribed to you. The typical recommended dosage for adults with an uncomplicated UTI is:
- Nitrofurantoin oral capsule monohydrate/macrocrystals (Macrobid): 100 milligrams (mg) every 12 hours.
- Nitrofurantoin oral capsule macrocrystals (Macrodantin): 50 to 100 mg four times per day.
- Nitrofurantoin oral liquid (Furadantin): 50 to 100 mg four times a day.
How long you’ll need to take nitrofurantoin depends on the form you’re prescribed and the severity of your UTI. The usual treatment duration for an uncomplicated UTI is around 5 days, but your doctor may prescribe a shorter course.
People with penises might have to take an antibiotic course for a UTI longer than people with vaginas because the bacteria can go into the prostate gland, and the infection is more likely to be considered complicated.
To improve the effectiveness of nitrofurantoin and to help prevent antibiotic resistance, doctors recommend:
- taking nitrofurantoin with food to help your body absorb it
- taking your dose at about the same time every day
- making sure that you are not skipping doses
Be sure to follow the dosage your doctor prescribes. Do not change your dosage of nitrofurantoin without talking with your doctor.
How does nitrofurantoin work?
Nitrofurantoin works by killing and stopping the growth of bacteria. It is an older antibiotic. Although it’s possible to develop antibiotic resistance to nitrofurantoin, it is less common than resistance to other antibiotics.
A 2021 research review found that nitrofurantoin was as effective at treating uncomplicated UTIs as other kinds of antibiotics.
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Antibiotics are the first-line treatment for UTIs. A doctor might prescribe a different antibiotic to nitrofurantoin, such as:
- trimethoprim-sulfamethoxazole(Bactrim)
- fosfomycin (Monurol)
If you are hospitalized for a complicated UTI, a doctor might try different antibiotics in addition to other treatments. Broad-spectrum antibiotics that are effective against many different kinds of bacteria may also be useful if the initial antibiotic does not work.
Summary
Nitrofurantoin is an antibiotic that can help treat a UTI. It usually gets to work within a few days, but you’ll need to take a course of this drug for around 5 days. You may need to take it for longer if you have more severe symptoms or complications.
Nitrofurantoin works by killing bacteria. Although it is an older antibiotic, studies have found it to be as effective as other antibiotics at treating uncomplicated UTIs and other bacterial infections.
If you don’t notice any improvements within a few days of taking nitrofurantoin, or your UTI symptoms worsen, let your doctor know as soon as possible.
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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.