Nitrofurantoin MONO-MACRO – Uses, Side Effects, and More
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.
Nitrofurantoin, oral capsule
Nitrofurantoin is a prescription drug that comes as an oral capsule and an oral suspension.
Nitrofurantoin oral capsule is available as the brand-name drugs Macrobid and Macrodantin. It’s also available as a generic drug. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in all strengths or forms as the brand-name drug.
Why it’s used
Nitrofurantoin oral capsule treats and prevents urinary tract infections that are caused by certain types of bacteria.
How it works
Nitrofurantoin belongs to a class of drugs called antimicrobials or antibiotics. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.
Nitrofurantoin helps kill the bacteria that cause urinary tract infections. It only works against certain types of bacteria.
Nitrofurantoin oral capsule may cause drowsiness. It may also cause other side effects.
More common side effects
The more common side effects of nitrofurantoin can include:
- nausea
- vomiting
- loss of appetite
- stomach pain
- diarrhea
- numbness in your hands and feet
- pain in your hands and feet
- weakness
- dizziness
- headache
- drowsiness
If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk with your doctor or pharmacist.
Serious side effects
Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:
- Lung inflammation. Symptoms can include:
- tiredness
- shortness of breath
- fever
- chills
- cough
- chest pain
- itching
- yellowing of your skin or the whites of your eyes
- nausea or vomiting
- dark urine
- loss of appetite
- numbness or tingling in your hands and feet
- muscle weakness
- tiredness
- weakness
- pale skin
- very loose or watery stools
- bloody stools
- stomach pain
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare professional who knows your medical history.
Nitrofurantoin oral capsule can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.
To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk with your doctor or pharmacist.
Examples of drugs that can cause interactions with nitrofurantoin are listed below.
Drugs you should not use with nitrofurantoin
Do not take these drugs with nitrofurantoin. Examples of these drugs include:
- Antacids such as Gaviscon that contain magnesium trisilicate: These drugs can make nitrofurantoin less effective.
- Probenecid and sulfinpyrazone: Taking these drugs while you’re taking nitrofurantoin may cause harmful levels of nitrofurantoin to build up in your blood. High levels of this drug in your body raise your risk of side effects, while reduced levels in your urine can make the drug less effective.
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare professional about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Nitrofurantoin oral capsule comes with several warnings.
Allergy warning
Nitrofurantoin can cause a severe allergic reaction. Symptoms can include:
- trouble breathing
- swelling of your throat or tongue
If you have an allergic reaction, call your doctor or local poison control center right away. If your symptoms are severe, call 911 or go to the nearest emergency room.
Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).
Warnings for people with certain health conditions
For people with kidney disease: If you have a history of kidney disease, you may not be able to clear nitrofurantoin from your body well. This could lead to a buildup of nitrofurantoin. This raises your risk of side effects.
For people with liver disease: You should not use nitrofurantoin. It can make your liver damage worse.
Warnings for other groups
For pregnant women: During weeks 0–37 of pregnancy, nitrofurantoin is a category B pregnancy drug. That means two things:
- Research in animals has not shown a risk to the fetus when the mother takes the drug.
- There aren’t enough studies done in humans to show if the drug poses a risk to the fetus.
Talk with your doctor if you’re pregnant or plan to become pregnant. Animal studies do not always predict the way humans would respond.
Nitrofurantoin can cause red blood cell problems in a newborn. For this reason, women who are pregnant should not take this drug:
- when they are at term (38–42 weeks of pregnancy),
- during labor and delivery
- if they think they are in labor
Call your doctor if you become pregnant while taking this drug.
For women who are breastfeeding: Nitrofurantoin may pass into breast milk and cause side effects in a child who is breastfed. Talk with your doctor about breastfeeding your child. You may need to decide whether to stop breastfeeding or stop taking this medication.
For seniors: The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects. If you’re older than 65 years, nitrofurantoin may not be a good choice for you.
For children: Do not use any form of nitrofurantoin in infants younger than 1 month. Macrodantin and its generic form are safe for use in children older than 1 month. Macrobid and its generic form have not been studied in children younger than 12 years of age. They should not be used in this age group.
This dosage information is for nitrofurantoin oral capsule. All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:
- your age
- the condition being treated
- how severe your condition is
- other medical conditions you have
- how you react to the first dose
Forms and strengths
Generic: Nitrofurantoin
- Form: oral capsule (generic for Macrobid)
- Strength: 100 mg (75 mg nitrofurantoin monohydrate and 25 mg nitrofurantoin macrocrystals)
- Form: oral capsule (generic for Macrodantin)
- Strengths: 25 mg, 50 mg, 100 mg
Brand: Macrobid
- Form: oral capsule
- Strength: 100 mg (75 mg nitrofurantoin monohydrate and 25 mg nitrofurantoin macrocrystals)
Brand: Macrodantin
Dosage for treatment of urinary tract infections
Adult dosage (ages 18–64 years)
- Macrodantin and its generic form: 50–100 mg four times per day. Length of treatment varies.
- Macrobid and its generic forms: 100 mg every 12 hours for 7 days.
Child dosage (ages 12–17 years)
- Macrodantin and its generic form: 5–7 mg/kg of body weight per day in four divided doses. Length of treatment may vary.
- Macrobid and its generic form: 100 mg every 12 hours for 7 days.
Child dosage (ages 1 month–11 years)
- Macrodantin and its generic form: 5–7 mg/kg of body weight per day in four divided doses. Length of treatment may vary.
- Macrobid and its generic form: These drugs have not been studied in children younger than 12 years. They should not be used in this age group.
Child dosage (ages 0–1 month)
- Macrodantin and its generic form: These drugs should not be used in children younger than 1 month.
- Macrobid and its generic form: These drugs have not been studied in children younger than 12 years. They should not be used in this age group.
Senior dosage (ages 65 years and older)
The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects. Your doctor may start you on a lowered dosage or a different treatment schedule. This can help keep levels of this drug from building up too much in your body.
Dosage for prevention of urinary tract infections
Adult dosage (ages 18–64 years)
- Macrodantin and its generic form: 50–100 mg at bedtime.
- Macrobid and its generic form: These drugs are not used for the prevention of urinary tract infections.
Child dosage (ages 1 month–17 years)
- Macrodantin and its generic form: 1 mg/kg of body weight once per day or divided into two doses per day.
- Macrobid and its generic form: These drugs are not used for the prevention of urinary tract infection.
Child dosage (ages 0–1 month)
- Macrodantin and its generic form: These drugs should not be used in children younger than 1 month.
- Macrobid and its generic form: These drugs are not used for the prevention of urinary tract infections.
Senior dosage (ages 65 years and older)
The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects. Your doctor may start you on a lowered dosage or a different treatment schedule. This can help keep levels of this drug from building up too much in your body.
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.
Nitrofurantoin oral capsule is used for short-term treatment of urinary tract infections. The brand-name drug Macrodantin and its generic form may also be used for long-term prevention of urinary tract infections.
This drug comes with serious risks if you don’t take it as prescribed.
If you stop taking the drug suddenly or don’t take it at all: Your urinary tract infection may not go away and may get worse. If you stop taking this drug suddenly, the bacteria that caused your urinary tract infection could become resistant to this drug. That means it won’t work for you anymore.
If you miss doses or don’t take the drug on schedule: Your medication may not work as well or may stop working completely. The bacteria that caused your urinary tract infection could become resistant to this drug. That means it won’t work for you anymore. For this drug to work well, a certain amount needs to be in your body at all times.
If you take too much: You could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include:
If you think you’ve taken too much of this drug, call your doctor or seek guidance from the American Association of Poison Control Centers at 800-222-1222 or through their online tool. But if your symptoms are severe, call 911 or go to the nearest emergency room right away.
What to do if you miss a dose: Take your dose as soon as you remember. But if you remember just a few hours before your next scheduled dose, take only one dose. Never try to catch up by taking two doses at once. This could result in dangerous side effects.
How to tell if the drug is working: The symptoms of your urinary tract infection should get better.
Keep these considerations in mind if your doctor prescribes nitrofurantoin oral capsule for you.
General
Take nitrofurantoin with food. This may help reduce upset stomach symptoms and allow the drug to work better.
Storage
- Store nitrofurantoin at a temperature between 68°F and 77°F (20°C and 25°C). Macrobid and generic Macrobid can be stored between 59°F and 86°F (15°C and 30°C).
- Keep nitrofurantoin away from light.
- Don’t store this medication in moist or damp areas, such as bathrooms.
Refills
A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.
Travel
When traveling with your medication:
- Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
- Don’t worry about airport X-ray machines. They can’t hurt your medication.
- You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled container with you.
- Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.
Clinical monitoring
Your doctor may monitor you during your treatment. If you are taking nitrofurantoin for long-term prevention of urinary tract infections, your doctor may do blood tests from time to time. These tests check your liver and kidney function.
There are other drugs available to treat your condition. Some may be better suited for you than others. Talk with your doctor about other drug options that may work for you.
Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
Last medically reviewed on August 12, 2021
- Urinary Tract Infection
- Infectious Diseases / Bacteria / Viruses
- Urology / Nephrology
- Drugs
How we reviewed this article:
Medical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.
- Furadantin — nitrofurantoin suspension. (2021).
https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=00af0dea-ac7b-43f2-9f51-2a9f9e7f7d21&type=display - Macrobid — nitrofurantoin monohydrate/macrocrystalline capsule. (2019).
http://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8f270a9f-12a1-44d4-bc7e-873613555801 - Macrodantin — nitrofurantoin macrocrystals capsule. (2017).
http://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=89d8696b-f9ce-9691-6222-8416ca143bba
Nitrofurantoin MONO-MACRO – Uses, Side Effects, and More
This medication is an antibiotic used to treat bladder infections (acute cystitis). It works by stopping the growth of bacteria.This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.This medication should not be used in infants younger than 1 month old (see also Precautions section). This drug should not be used to treat infections outside the bladder (including kidney infections such as pyelonephritis or perinephric abscesses).
How to use Nitrofurantoin MONO-MACRO
Take this medication by mouth with food as directed by your doctor, usually twice daily (every 12 hours). Swallow the medication whole for best results.
Do not use magnesium trisilicate-containing antacids while taking this medication. These antacids can bind with nitrofurantoin, preventing its full absorption into your system.
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.
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 return of the infection.
Inform your doctor if your condition persists or worsens.
Side Effects
Nausea, headache may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.
Remember that this medication has been prescribed because your doctor 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 cause your urine to turn dark yellow or brown in color. This is usually a harmless, temporary effect and will disappear when the medication is stopped. However, dark brown urine can also be a sign of rare side effects (liver problems or anemia). Get medical help right away if you notice dark urine along with any of the following symptoms: persistent nausea/vomiting, stomach/abdominal pain, yellowing eyes/skin, tiredness, fast/pounding heartbeat.
Tell your doctor right away if you have any serious side effects, including: eye pain, vision changes, mental/mood changes, persistent/severe headaches, new signs of infection (such as fever, persistent sore throat), easy bruising/bleeding.
Get medical help right away if you have any very serious side effects, including: numbness/tingling of the hands/feet, unusual muscle weakness.
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.
This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop: diarrhea that doesn’t stop, abdominal or stomach pain/cramping, blood/mucus in your stool.
If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.
Use of nitrofurantoin for prolonged or repeated periods may result in oral thrush or a new vaginal yeast 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.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US – Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada – Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.