Key takeaways:
Macrobid (nitrofurantoin monohydrate/macrocrystals) is a prescription antibiotic. It’s used to treat urinary tract infections (UTIs) in adults and children ages 12 years and older. It comes as a 100 mg oral capsule that’s taken twice daily.
Children and adults take the same Macrobid dosage. Official labeling recommends 7 days of treatment, but your healthcare provider may recommend a shorter 5-day course.
Macrobid is also available as a lower-cost generic. GoodRx can help you save over 80% off the average retail price at certain pharmacies.
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If you’ve ever experienced a urinary tract infection (UTI), you know it can be quite uncomfortable. You may even be part of the 8 million clinic visits that healthcare providers schedule each year to tackle UTIs.
If so, you may have been prescribed Macrobid (nitrofurantoin monohydrate/macrocrystals). It’s a first-choice prescription antibiotic for treating uncomplicated UTIs.
In this guide, we’ll review typical Macrobid dosages. Keep in mind these are recommended by its official labeling. Your healthcare provider might have you take Macrobid differently.
Reach out to your healthcare provider or pharmacist if you have any questions about taking Macrobid.
What’s the typical Macrobid dosage for adults?
Macrobid comes as a 100 mg oral capsule. The typical recommended dose for adults with uncomplicated UTIs is 100 mg (1 capsule) by mouth 2 times a day (every 12 hours) for 7 days. But your healthcare provider may recommend a shorter course of 5 days instead. Studies show that a 5-day Macrobid treatment course is also well-tolerated and effective.
Duration aside, it’s best to take Macrobid with food. Food helps your body absorb Macrobid better, boosting its effectiveness.
In fact, taking Macrobid with food can help raise the amount that enters your bloodstream by about 40%. Food may also help prevent some stomach-related side effects, like upset stomach and diarrhea.
What’s the typical Macrobid dosage for children?
Macrobid is FDA-approved to treat uncomplicated UTIs in children ages 12 and older. The dose for kids is the same as adults, which is 100 mg by mouth 2 times a day for 7 days. Your healthcare provider may also consider a shorter 5-day course for your child.
Children should also take Macrobid with food to help with medication absorption and stomach-related side effects.
But, Macrobid isn’t FDA-approved to treat UTIs in kids younger than 12. Macrodantin, a slightly different version of nitrofurantoin, is an option for children younger than 12. It’s approved to treat or prevent UTIs in adults and children ages 1 month and older. Macrodantin dosing for your child is based on their body weight, but it’s usually taken by mouth 4 times per day.
Macrodantin comes as 25 mg, 50 mg, and 100 mg capsules. Furadantin (nitrofurantoin oral suspension) is also available as a liquid version of Macrodantin. It comes as a 25 mg/5 mL oral suspension.
Reach out to your child’s healthcare provider about the best option for treating their UTI. They may or may not recommend Macrobid or Macrodantin.
Are there any dosage adjustments for medical conditions?
Certain medical conditions can change how a medication works in the body. When it comes to Macrobid, your kidney health is a big factor. If the kidneys aren’t working as well as they could, Macrobid could build up in the body and cause more side effects.
Dosage for people with kidney problems
There’s no recommended dose adjustment for Macrobid in people with mild kidney problems. But if your kidney problems are more severe, you may want to avoid it altogether.
The manufacturer recommends that people with a creatinine clearance (CrCl) of less than 60 mL per minute should avoid taking Macrobid. CrCl is a lab test your healthcare provider can do to find out how well your kidneys are working.
If your CrCl is too low, your kidneys may not be working well enough to safely remove Macrobid from the body. This can happen with health conditions like chronic kidney disease. Macrobid may build up in your blood and cause more side effects such as nausea, vomiting, and headache.
The Beers Criteria — created by the American Geriatrics Society — looks at which medications may not be appropriate for older adults. They take a more casual stance than the manufacturer when it comes to kidney function. The Beers Criteria recommends avoiding Macrobid if your kidney function is slightly more severe (CrCl of less than 30 mL per minute).
Let your healthcare provider know if you have any kidney problems before starting Macrobid. They can make the final call on if Macrobid is the right medication to treat your UTI.
What happens if you miss a dose of Macrobid?
If you forget to take your Macrobid dose, take it as soon as you remember. But if it’s too close to the time of your next dose, you can skip the missed dose and take the next dose as scheduled. Never double up on missed Macrobid pills. This worsens the risk of side effects.
If you need help remembering to take Macrobid, there are handy tools available. If you have a smartphone, medication reminder apps can be helpful. You can also incorporate Macrobid into your daily pill organizer if you have one.
Reach out to your pharmacist and healthcare provider for more useful tips.
What should you do if you take too much Macrobid?
It can be scary if you think you accidentally took too much medication. But when it comes to Macrobid, it’ll likely be OK. You may experience vomiting if you take too much Macrobid, but there haven’t been reports of other side effects or issues from Macrobid overdoses.
Still, if you or a loved one might have taken too much Macrobid, reach out to your healthcare provider or call Poison Control at 1-800-222-1222. They may recommend drinking fluids to help clear Macrobid from your body.
But if your symptoms feel severe, call 911 or go to the nearest emergency room as soon as you can.
Remember to keep all medications out of reach and locked away from children and pets to prevent accidental poisoning.
How to save on Macrobid
There are many ways to save on Macrobid, which is available as both a brand-name and generic medication.
GoodRx can help you save over 80% off the average retail price of the generic version. Generic Macrobid’s price at certain pharmacies is less than $7.69 with a free GoodRx discount.
If you have Medicare, you can also save on your Macrobid prescription. In fact, all Medicare prescription plans cover Macrobid. You will likely pay between $1 and $3 at many pharmacies.
The bottom line
Macrobid is an oral capsule that treats UTIs. Adults and children ages 12 and older usually take one 100 mg capsule by mouth twice a day for 5 to 7 days.
Let your healthcare provider know if you have any kidney problems before starting Macrobid. And if you accidentally take too much Macrobid, reach out to your healthcare provider or contact Poison Control for guidance.
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References
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American Urological Association. (2022). Urinary tract infections in adults.
A-S Medication Solutions. (2022). Nitrofurantoin monohydrate/macrocrystals [package insert].
Casper Pharma LLC. (2021). Furadantin [package insert].
Guideline Central. (2022). Beers criteria for potentially inappropriate medication use in older adults.
Gupta, K., et al. (2011). International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Infectious Diseases Society of America.
Lee, R. A., et al. (2021). Appropriate use of short-course antibiotics in common infections: Best practice advice from the American College of Physicians. Annals of Internal Medicine.
Mattoo, T. K., et al. (2021). Contemporary management of urinary tract infection in children. Pediatrics.
MedlinePlus. (2022). Nitrofurantoin.
