Do not use Nitrofurantoin if:

• you are allergic to any ingredient in Nitrofurantoin;
• you have little or no urine formation or you have kidney problems;
• you are pregnant and at term (38 to 42 weeks pregnant), the onset of labor is about to occur, or during labor and delivery;
• the patient is younger than 1 month old.

• Nitrofurantoin may cause drowsiness, dizziness, lightheadedness, or blurred vision. These effects may be worse if you take it with alcohol or certain medicines. Use Nitrofurantoin with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Nitrofurantoin may cause severe lung damage that may be permanent or fatal. If lung damage occurs, it may be sudden or chronic and may not be immediately recognized. This usually occurs in patients who are taking the medicine for 6 months or longer. Contact your health care provider immediately if chest pain, coughing, difficulty breathing (especially upon exertion), or noticeable changes in lung function occur. Symptoms usually occur during the first 1 to 2 weeks of therapy.
• Mild diarrhea is common with antibiotic use. However, a more serious form of diarrhea (pseudomembranous colitis) may rarely occur. This may develop while you use the antibiotic or within several months after you stop using it. Contact your doctor right away if stomach pain or cramps, severe diarrhea, or bloody stools occur. Do not treat diarrhea without first checking with your doctor.
• Long-term or repeated use of Nitrofurantoin may cause a second infection. Tell your doctor if signs of a second infection occur. Your medicine may need to be changed to treat this.
• Nitrofurantoin only works against bacteria; it does not treat viral infections (e.g., the common cold).
• Be sure to use Nitrofurantoin for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The bacteria could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
• Nitrofurantoin may discolor the urine. This is normal and not a cause for concern.
• Diabetes patients - Nitrofurantoin may cause the results of some tests for urine glucose to be wrong. Ask your doctor before you change your diet or the dose of your diabetes medicine.
• Lab tests, including liver function, kidney function, and complete blood cell counts, may be performed while you use Nitrofurantoin. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Use Nitrofurantoin with caution in the elderly; they may be more sensitive to its effects, especially side effects involving the lungs and liver.
• Nitrofurantoin should not be used in children younger than 1 month old; safety and effectiveness in these children have not been confirmed.
• Methotrexate should be used with extreme caution in children younger than 2 years old; safety and effectiveness in these children have not been confirmed.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Nitrofurantoin while you are pregnant. Do not use Nitrofurantoin if you are at term (38 to 42 weeks pregnant), when the onset of labor is about to occur, or during labor and delivery. Nitrofurantoin is found in breast milk. Do not breast-feed while taking Nitrofurantoin.

  
  Possible Side Effects
  
  

  Check with your doctor if any of these most common side effects persist or become bothersome:

  • chills; cough; dizziness; drowsiness; fever; headache; loss of appetite; nausea; rash; tingling or numbness in fingers or toes; upset stomach; vomiting.
  Seek medical attention right away if any of these severe side effects occur:
  • severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bizarre behavior; bloody stools; chest pain; coughing; general body discomfort; increased pressure in the head; inflammation of the pancreas (stomach tenderness; nausea; vomiting; fever; increased pulse); tingling, numbness, or burning of the fingers and toes; severe diarrhea; shortness of breath, especially when using energy; stomach pain/cramps; yellowing of the skin or eyes.
  
  
  More Information
  
  

  Nitrofurantoin is to be used only by the patient for whom it is prescribed. Do not share it with other people.