Nitrofurantoin

By Medically reviewed by hellodoktor

Generic Name: Nitrofurantoin Brand Name(s): Generics only. No brands available.

Uses

What is Nitrofurantoin used for?

Nitrofurantoin is used to treat or prevent certain urinary tract infections.

This medication is an antibiotic that works by stopping the growth of bacteria. It will not work for viral infections (e.g., common cold, flu). Unnecessary use or overuse of any antibiotic can lead to its decreased effectiveness.

Nitrofurantoin should not be used in children less than one month of age due to the risk of a certain blood problem (hemolytic anemia).

How should I take Nitrofurantoin?

Take this medication by mouth, with food or milk, as directed by your doctor. This medication is usually taken four times daily to treat an infection or once daily at bedtime to prevent infections. Swallow the medication whole. Avoid using magnesium trisilicate-containing antacids while taking this medication. Magnesium trisilicate-containing antacids bind with nitrofurantoin, preventing its full absorption.

Dosage and duration is based on your medical condition and response to therapy. For children, the dosage is also based on body weight.

For the best effect, take this antibiotic at evenly spaced times. To help you remember, take this medication at the same time(s) every day.

When taking this medication to prevent infection, take it exactly as directed by your doctor. Do not skip doses or stop taking it without your doctor’s approval. Inform your doctor if you notice signs of a new urinary tract infection (e.g., pain while you are urinating).

If you are taking this medication to treat an infection, continue to take this medication until the full-prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may allow bacteria to continue to grow, which may result in a relapse of the infection. Inform your doctor if your condition persists or worsens.

Precautions & warnings

What should I know before using Nitrofurantoin?

Before taking nitrofurantoin, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: little or no urine output (oliguria or anuria), severe kidney disease, certain genetic conditions (glucose-6-phosphate dehydrogenase deficiency), a history of liver problems due to nitrofurantoin use in the past.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: certain blood disorders (e.g., anemia), kidney or liver problems, lung diseases, certain nerve problems (peripheral neuropathy), certain eye diseases (optic neuritis), diabetes, untreated mineral imbalance, vitamin B deficiency.

Nitrofurantoin may cause live bacterial vaccines (such as typhoid vaccine) to not work as well. Do not have any immunizations/vaccinations while using this medication unless your doctor tells you to.

Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, older adults may be at a greater risk for side effects while using this drug, especially nerve, liver or lung problems (see Side Effects section).

This medication should be used only when clearly needed during pregnancy. This medication should not be taken if you are at term (weeks 38-42 of pregnancy), near or at the time of delivery due to possible harm to the newborn, such as a certain blood problem (hemolytic anemia). Discuss the risks and benefits with your doctor.

This medication passes into breast milk and may have undesirable effects on nursing infants less than one month old and infants with a certain genetic condition (G-6-PD deficiency). Consult your doctor before breast-feeding.

Is it safe during pregnancy or breast-feeding?

There are no adequate studies in women for determining risk when using this Nitrofurantoin during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking Nitrofurantoin. Nitrofurantoin is pregnancy risk category B according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk,
  • B=No risk in some studies,
  • C=There may be some risk,
  • D=Positive evidence of risk,
  • X=Contraindicated,
  • N=Unknown

Side effects

What side effects can occur from Nitrofurantoin?

Nausea, vomiting, loss of appetite, or headache may occur. Take this medication with food to help minimize nausea. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

This medication may cause your urine to turn dark yellow or brown in color. This effect is harmless and will disappear when the medication is stopped.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

This medication may rarely cause very serious (possibly fatal) lung problems. Lung problems may occur within the first month of treatment or after long-term use of nitrofurantoin (generally for 6 months or longer). Get medical help right away if you develop symptoms of lung problems, including: persistent cough, chest pain, shortness of breath/trouble breathing, joint/muscle pain, bluish/purplish skin.

Tell your doctor right away if any of these rare but very serious side effects occur: new signs of infection (e.g., fever, persistent sore throat), easy bruising/bleeding, mental/mood changes, persistent or severe headaches, vision changes.

This drug may rarely cause serious (possibly fatal) liver disease, blood or nerve problems. Tell your doctor right away if you notice any of the following rare but very serious side effects: persistent nausea/vomiting, dark urine, yellowing of eyes/skin, unusual/persistent fatigue, fast/pounding heartbeat, numbness/tingling of the arms/legs, muscle weakness.

This medication may rarely cause a severe intestinal condition (Clostridium difficile-associated diarrhea) due to a type of resistant bacteria. This condition may occur during treatment or weeks to months after treatment has stopped. Do not use anti-diarrhea products or narcotic pain medications if you have any of the following symptoms because these products may make them worse. Tell your doctor right away if you develop: persistent diarrhea, abdominal or stomach pain/cramping, blood/mucus in your stool.

Use of this medication for prolonged or repeated periods may result in oral thrush or a new vaginal yeast infection (e.g., oral or vaginal fungal infection). Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.

Interactions

What drugs may interact with Nitrofurantoin?

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: sulfinpyrazone.

Although most antibiotics are unlikely to affect hormonal birth control such as pills, patch, or ring, a few antibiotics (such as rifampin, rifabutin) can decrease their effectiveness. This could result in pregnancy. If you use hormonal birth control, ask your doctor or pharmacist for more details.

This drug can affect the results of certain urine glucose tests (cupric sulfate-type). Make sure laboratory personnel and your doctors know you use this drug.

Nitrofurantoin may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Does food or alcohol interact with Nitrofurantoin?

Nitrofurantoin may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Nitrofurantoin?

Nitrofurantoin may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this Nitrofurantoin.

What is the dose of Nitrofurantoin for an adult?

Usual Adult Dose for Cystitis

Regular release: 50 to 100 mg orally 4 times a day for 1 week or for at least 3 days after urine sterility is obtained

Dual release: 100 mg orally twice a day for 7 days

Comment:

-This drug should be given with food to improve drug absorption and, in some patients, tolerance.

Use: Cystitis

Usual Adult Dose for Cystitis Prophylaxis

Regular release: 50 to 100 mg orally once a day at bedtime

Comments:

-This drug should be given with food to improve drug absorption and, in some patients, tolerance.

-Patients receiving long-term therapy should be monitored periodically for changes in renal function.

Use: Cystitis prophylaxis

Renal Dose Adjustments

-CrCl 60 mL/min or more: No adjustment recommended

-Anuria, oliguria, or significant renal insufficiency (CrCl less than 60 mL/min or significantly elevated creatinine): Contraindicated

Liver Dose Adjustments

This drug undergoes hepatic elimination; a dosage reduction may be necessary for patients with hepatic dysfunction.

Dialysis

This drug can be hemodialyzed.

Other Comments

Administration advice:

-This drug should be given with food to improve drug absorption and, in some patients, tolerance.

Monitoring parameters:

-Renal, liver, and pulmonary function (especially if on long term therapy)

General:

-The lowest effective dose should be used for prophylactic or for long-term suppressive therapy.

Patient advice:

-This drug may cause dizziness and drowsiness; avoid driving or operating machinery if you feel drowsy or dizzy.

-Take this drug with food or milk, avoid missing doses, and complete the entire course of therapy.

-Do not use antacid preparations containing magnesium trisilicate while taking this drug.

-This drug may cause a brownish discoloration of the urine.

-Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as 2 or more months after having taken the last dose of the antibiotic; if this occurs, contact your physician as soon as possible.

What is the dose of Nitrofurantoin for a child?

Usual Pediatric Dose for Cystitis

Regular release:

1 month or older: 5 to 7 mg/kg/day (up to 400 mg/day) orally in 4 divided doses for 1 week or for at least 3 days after urine sterility is obtained

Dual release:

Greater than 12 years: 100 mg orally twice a day for 7 days for 1 week or for at least 3 days after urine sterility is obtained

Comment:

-This drug should be given with food to improve drug absorption and, in some patients, tolerance.

Use: Cystitis

Usual Pediatric Dose for Cystitis Prophylaxis

Regular release:

1 month or older: Doses as low as 1 mg/kg/day (up to 100 mg/day) orally in 1 to 2 divided doses may be adequate

Comments:

-This drug should be given with food to improve drug absorption and, in some patients, tolerance.

-Patients receiving long-term therapy should be monitored periodically for changes in renal function.

Use: Cystitis prophylaxis

Precautions

Safety and efficacy have not been established in patients younger than 1 month.

How is Nitrofurantoin available?

Nitrofurantoin is available in the following dosage forms and strengths:

  • Oral capsule,
  • Oral suspension,
  • Compounding powder.

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Nitrofurantoin, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: April 5, 2018 | Last Modified: September 12, 2019

Sources
You might also like