Medically Approved

Nitrofurantoin can help you overcome a urinary tract infection

How nitrofurantoin can help you overcome a urinary tract infection

Optum Perks Author

By Optum Perks Author

The nonstop urge to pee (with very little to show for it). The burning pain. The urine that looks cloudy or pink. With symptoms like these, a urinary tract infection (UTI) is usually to blame. And since UTIs are typically caused by bacteria, you’ll need an antibiotic, such as nitrofurantoin (Macrodantin®, Macrobid®), to knock it out.

“When we think of bacteria, there are 6 to 7 ways a drug can work in the cell,” says Kayla Stover, PharmD, an associate professor of pharmacy practice at the University of Mississippi Medical Center in Jackson. “Some attack the outside, some work on proteins on the inside, and some work on DNA, which impacts replication of the cell. This drug probably does all of these things.”

The exact formulation you’ll be prescribed usually depends on whether you’re dealing with an acute active infection or are someone who routinely gets infections. If you get more than 2 infections in 6 months, or 3 in a year, then you’re in the recurrent zone. In this case, you’ll likely take Macrodantin (branded name of nitrofurantoin) once a day to prevent future infections.

“If you keep getting UTIs, you’ll need to keep treating them,” Stover says. “You can be on Macrodantin for months or years, and we see this particularly in women or men who are in nursing homes and have recurrent UTIs due to catheter or other anatomic issues.”

For the pop-up UTI, your doctor will likely prescribe Macrobid, which you take twice a day for a week. (On a prescription label, BID means “twice a day.”)


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How long does nitrofurantoin take to work?

You should feel better within a couple of days, Stover says. One thing to remember when it comes to this drug: Always finish the course of your medication, even if you no longer have symptoms. Stopping sooner can increase your risk of developing an antibiotic-resistant infection in the future.

If you’re taking this medication on a long-term basis for prevention, your doctor will advise you when it’s safe to stop.

What are the side effects of nitrofurantoin?

The most common complaints are headaches and nausea. To ease these symptoms, take an over-the-counter pain reliever such as acetaminophen or ibuprofen as needed, and always pair this drug with food, Stover says.

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Also, avoid taking an antacid or indigestion product that contains magnesium trisilicate, such as Gaviscon. This form of magnesium can decrease concentrations of nitrofurantoin, possibly leading to failed therapy or even resistance as a result, says Stover.

“Some other concerns about this drug can sound scary,” Stover says. “For example, if you have bad kidney function, this drug can accumulate a little bit. It can have higher concentrations in the body than we want to see.”

Taking this drug can sometimes lead to numbness, tingling, loss of sensation in your fingers or toes, lung issues or difficulty breathing, but these side effects are very rare, Stover says.

“Most people tolerate this drug very well,” she says.

Can you take it with cranberry juice?

If you’re prescribed this medication, be sure to always take it with water. “You need to flush out your bladder as well as your urethra and kidneys,” says Stefanie Ferreri, PharmD, chair of the Division of Practice Advancement and Clinical Education at UNC Eshelman School of Pharmacy in Chapel Hill, North Carolina.

So will cranberry juice work? “There’s not a lot of evidence that cranberry juice is going to treat an infection,” Ferreri says. “It does have some acidity, so if the pH balance is off in the urinary tract or bladder, it can help maintain that balance of acidity. It’s not a tried-and-true preventive, but it won’t hurt.”

If you’re a cranberry fan, stick to 4 to 8 ounces a day of 100% pure juice. (If the word “cocktail” is on the label, step away.) “Make sure the juice you’re drinking doesn’t have extra sugar,” she says. “Those sugars are not going to help with your pH balance.” And with less acid in the urinary tract, the easier it is for that bacteria to flourish.

Did you know that your urine can reveal a lot about the state of your health? Learn the signs to look for—and what they could mean.

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