Patient Medication Information: uses, side effects, how to take - Nitrofurantoin
What NITROFURANTOIN is used for:
NITROFURANTOIN is used to treat urinary tract infections caused by certain bacteria.
Antibacterial drugs like NITROFURANTOIN treat only bacterial infections. They do not treat viral infections.
How NITROFURANTOIN works:
NITROFURANTOIN works to:
- Stop growth of bacteria.
- Kill the bacteria.
- Reduce the infection in your body.
The ingredients in NITROFURANTOIN are:
Medicinal ingredients: Nitrofurantoin
Non-medicinal ingredients: croscarmellose sodium, lactose monohydrate, magnesium stearate and microcrystalline cellulose.
NITROFURANTOIN comes in the following dosage form:
Tablets: 50 mg and 100 mg.
Do not use NITROFURANTOIN if:
- you are allergic (causing itching, redness of skin or difficulty breathing) to NITROFURANTOIN or any of the ingredients in NITROFURANTOIN tablets.
- you have kidney disease.
you are pregnant and close to giving birth.
- you have had a previous history of jaundice or liver disease associated with nitrofurantoin.
NITROFURANTOIN should not be given to infants under 1 month of age.
To help avoid side effects and ensure proper use, talk to your healthcare professional before you take NITROFURANTOIN. Talk about any health conditions or problems you may have, including if you:
- have diabetes.
- have anemia (a decrease in red blood cells causing pale skin, weakness and breathlessness) or a lack of vitamin B (particularly folate) or abnormal levels of salts in your blood.
- have a condition known as glucose-6-phosphate dehydrogenase deficiency.
- have any disease of lungs, liver or nervous system.
- have had diarrhea after taking antibiotics in the past.
- are planning to become pregnant.
- are breastfeeding or planning to breastfeed.
- are elderly and have lung or liver disease.
- have kidney problems.
- take any medicines that may impair your kidney function.
Other warnings you should know about:
Driving and using machines
NITROFURANTOIN Tablets may cause dizziness and drowsiness. You should not drive or use machinery if you are feeling dizzy and until such symptoms go away.
NITROFURANTOIN tablets contain lactose
This medicine contains lactose. If you have been told by your healthcare professional that you are intolerant to some sugars and you have to avoid them, contact your healthcare professional before taking this medicine.
Peripheral neuropathy
The following conditions may increase the chance of developing a side effect known as peripheral neuropathy. It can cause damage to the nerves, altered sense of feeling, like pins and needles:
- anemia (a decrease in red blood cells causing pale skin, weakness and breathlessness),
- diabetes,
- a lack of vitamin B,
- abnormal levels of salts in your blood,
- you are suffering from an illness that makes you very tired.
Liver disease
NITROFURANTOIN may cause liver problems. Symptoms include nausea, vomiting, loss of appetite, feeling generally unwell, fever, itching, yellowing of the skin and eyes, light colored bowel motions, and dark colored urine. Your healthcare professional may want to regularly check how your liver is working. If you get liver disease while taking NITROFURANTOIN, you should immediately stop taking the medicine and talk to your healthcare professional.
- When taking NITROFURANTOIN your urine may turn brown or rust-coloured.
- NITROFURANTOIN may interfere with the production of sperm and decrease sperm count.
Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.
The following may interact with NITROFURANTOIN:
- medicines used to treat heartburn, indigestion or acid reflux called antacids, such as magnesium trisilicate and magnesium hydroxide.
- medicines used to make the urine more acidic, such as ammonium chloride tablets.
- medicines used to make the urine more alkaline, such as sodium bicarbonate.
- medicines used to treat gout, such as probenecid and sulfinpyrazone.
- certain medicines used to treat bacterial infections, known as quinolones.
Taking NITROFURANTOIN may change the test results for sugar in your urine.
How to take NITROFURANTOIN:
- Although you may feel better early in treatment, NITROFURANTOIN should be used exactly as directed.
- Misuse or overuse of NITROFURANTOIN could lead to the growth of bacteria that will not be killed by NITROFURANTOIN (resistance). This means that NITROFURANTOIN may not work for you in the future.
- Do not share your medicine.
NITROFURANTOIN tablets should be taken with food or milk. This will help to avoid stomach upset and also to help the absorption.
Usual dose:
Adults: The usual dose is 50 mg to 100 mg four times a day for at least 1 week.
For long-term treatment to prevent urinary tract infections, your healthcare professional may reduce your dose to 50 mg to 100 mg once a day at bedtime.
Children: The usual dose will be calculated based on the child’s weight. It will be taken four times a day
For long-term treatment to prevent urinary tract infections, the healthcare professional may reduce the dose to once or twice a day.
Your healthcare professional will decide how long you should take NITROFURANTOIN.
Overdose:
| If you think you, or a person you are caring for, have taken too much NITROFURANTOIN, contact a healthcare professional, hospital emergency department, regional poison control centre or Health |
|---|
| Canada’s toll-free number, 1-844 POISON-X (1-844-764-7669) immediately, even if there are no signs or symptoms. |
Missed dose:
If you forget to take NITROFURANTOIN tablets, take the dose as soon as you remember. However, if it is almost time for your next dose, skip the missed dose. Do not use a double dose to make up for a forgotten dose.
Possible side effects from using NITROFURANTOIN:
These are not all the possible side effects you may have when taking NITROFURANTOIN. If you experience any side effects not listed here, tell your healthcare professional.
Side Effects may include:
- Headache
- Abdominal pain
- Loss of appetite
- Diarrhea
- Constipation
- Indigestion
- Short-term unusual hair loss or thinning
- Drowsiness
- Dizziness
- Joint pain
- Fever and chills
- Confusion
- Depression
- Euphoria
- Muscle pain
- Vertigo
Serious side effects and what to do about them
| Frequency / Side Effect / Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
|---|---|---|---|
| Frequency / Side Effect / Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
| Frequency / Side Effect / Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
| Frequency / Side Effect / Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
| Frequency / Side Effect / Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
| Only if severe | In all cases | ||
| Only if severe | In all cases | ||
| Only if severe | In all cases | ||
| Only if severe | In all cases | ||
| Only if severe | In all cases | ||
| UNKNOWN | |||
Blood and lymphatic system problems:
| √ | ||
infection with fever, chills, sore throat.
| |||
| Vertigo (sensation of spinning and feeling off balance even when not moving). | √ | ||
| Amblyopia (lazy eye): decreased vision, blurry vision, eyes pointing in different directions, droopy eyelid, squinting | √ | ||
| Problems of the gastrointestinal tract: Nausea, vomiting, burning sensation in abdomen, bloating, constipation. | √ | ||
| Pancreatitis (inflammation of the pancreas): Upper abdominal pain, fever, rapid heartbeat, tenderness when touching the abdomen. | √ | ||
| Drug Fever (fever caused by taking a medicine): fever, lack of energy. | √ | ||
| Allergic reaction: swelling of the face, eyes, lips, tongue or throat, trouble breathing or swallowing; sudden signs of allergy such as rash, itching or hives on the skin, swelling of the face, lips, tongue or | √ | ||
| other parts of the body, shortness of breath, wheezing or trouble breathing. | |||
| Lupus-like syndrome associated with pulmonary reactions (condition that mimics lupus): chest pain, shortness of breath, dry cough that may bring up blood, muscle pain, joint pain, sometimes with swelling, fever, feeling tired, weight loss. | √ | ||
| Vasculitis (swelling and inflammation of blood vessels): fever, headache, tiredness, weight loss, aches and pains. | √ | ||
| Urinary tract infection with bacteria that do not respond to treatment: pain or burning when urinating, frequent or urgent urination, cloudy or bloody urine, lower abdominal or back pain, fever or chills. | √ | ||
| Blood test results: Abnormal liver enzymes, decreased hemoglobin, increased serum phosphorus. | √ | ||
| Loss of the appetite. | √ | ||
| Pain in joints, muscle aches and pain. | √ | ||
Nervous system problems:
| √ | ||
eye.
| |||
| C. difficile colitis (inflammation of the colon caused by a bacteria called C. difficile): Watery diarrhea, stomach cramps, pain or tenderness, fever, pus or mucus in the stool, nausea, dehydration. | √ | ||
| Brown or rust-coloured urine. | √ | ||
| Lung and chest problems: fever, chills, cough, chest pain, shortness of breath, loss of consciousness, trouble breathing including asthmatic attack in patients with asthma, build up of fluids in the lungs, increased numbers of certain white blood cells which can cause abdominal pain, rash, weight loss, wheezing. | √ | ||
| Skin problems: red, raised skin rash, itchy rash, severe itching, eczema, hives, swelling of the face/lips/tongue/throat, and short-term hair loss. | √ | ||
| RARE | |||
Blood and lymphatic system problems:
| √ | ||
| Abdominal pain, and diarrhea. | √ | ||
| Liver problems: abdominal pain, | √ | ||
| nausea, vomiting, fever, moderate enlargement of the liver, loss of appetite, and signs of heart failure. | |||
Hepatitis (Inflammation of liver): Abdominal pain, fatigue, fever, itchiness, light coloured stool, trouble thinking clearly, yellowing of the skin. Cholestatic jaundice: dark urine, light-colored stools, generalized itchiness. | √ | ||
| Mental health problems: Confusion, depression, euphoria (feeling of great happiness or well-being), psychotic reaction (seeing or hearing things that are not there, having unusual thoughts or beliefs, or major changes in behaviour). | √ | ||
| Serious skin problems: Exfoliative dermatitis (severe inflammation and peeling of the skin): red and peeling skin, skin may flake off and cause significant loss of surface skin, lesions that crust over, areas of thickened skin, swollen lymph nodes, fever, malaise, viral or bacterial infections, trouble with body temperature due to skin loss. | √ | ||
| Erythema multiforme (an allergic skin reaction): raised red or purple skin patches, possibly with blister or crust in the center, possibly swollen lips, mild itching or burning. | √ | ||
| Stevens-Johnson syndrome (SJS) (severe skin rash): redness, blistering and/or peeling of the skin and/or inside of the lips, eyes, mouth, nasal passages or genitals, accompanied by fever, chills, headache, cough, body aches or swollen glands. | √ | ||
If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.
Reporting Side Effects
You can report any suspected side effects associated with the use of health products to Health Canada by:
NOTE: Contact your healthcare professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice. |
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Storage:
Store at temperature below 25°C. Protect from light.
Keep out of reach and sight of children.
If you want more information about NITROFURANTOIN:
- Talk to your healthcare professional.
- Find the full product monograph that is prepared for healthcare professionals and includes the Patient Medication Information by visiting the Health Canada Drug Product Database website (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-database.html); the manufacturer’s website (https://www.aapharma.ca/en/); or by calling 1-877-998-9097.
Date of Authorization: 2026-10-19