Drug
Nitrofurantoin
Pronounced
"NYE-trow-fyour-AN-toe-in"
Side Effects
Nausea, vomiting, loss of appetite, or headache may occur. Take this medication with food to help minimize nausea. If any of these effects last or get worse, tell 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: nausea/vomiting that doesn't stop, stomach/abdominal pain, yellowing eyes/skin, tiredness, fast/pounding heartbeat.
Tell your doctor right away if you have any serious side effects, including: headaches that are severe or don't go away, eye pain, vision changes, mental/mood changes, new signs of infection (such as sore throat that doesn't go away, fever), 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: cough that doesn't go away, 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.
Precautions
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.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, liver disease (including liver problems caused by nitrofurantoin in the past), a certain genetic condition (G-6-PD deficiency), lung disease, numbness/tingling of the arms/legs, vitamin B deficiency, mineral imbalance, blood disorders (such as anemia), diabetes, ongoing weakness due to long-term disease, certain eye disorders (such as optic neuritis).
Older adults may be at a greater risk for side effects while using this drug, especially nerve, liver or lung problems.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Nitrofurantoin may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using nitrofurantoin before having any immunizations/vaccinations.
During pregnancy, this medication should be used only when clearly needed. It must not be used if you are near the end of your pregnancy (38-42 weeks) or at the time of labor and delivery. Doing so may cause a certain blood disorder (hemolytic anemia) in your baby. Discuss the risks and benefits with your doctor.
This medication passes into breast milk and may have undesirable effects on nursing infants younger than 1 month old or those with a certain genetic condition (G-6-PD deficiency). Consult your doctor before breastfeeding.