Drug Profile

Breast-feeding Warning

Nitrofurantoin is excreted in human milk. Because of the potential for serious adverse effects in nursing infants, you should not take this drug while nursing.

Antibiotic-Associated Diarrhea

Antibiotic-associated diarrhea (AAD) is quite common and its incidence varies from 5% to 20% of patients depending on which antibiotic they are taking, although practically all antibiotics have been associated with AAD. Fortunately, most cases are mild and self-limited, ending with the cessation of use of the offending antibiotic. The antibiotics most commonly associated with this mild form of AAD include ampicillin, amoxicillin, cephalosporins and clindamycin.[1] There have been studies in children or adults in which the use of prophylactic yogurt in people using antibiotics has significantly reduced the occurrence or severity of AAD.[2],[3] However, 10% to 20% of all patients who get AAD (0.5% to 4% of patients using antibiotics) will get the more severe form of AAD known as pseudomembranous colitis (see below). If you are taking any antibiotic and develop diarrhea after starting to use the drug, call your physician to discuss whether another antibiotic should be used and to discuss the need for rehydration due to the fluid loss from the diarrhea.

Pseudomembranous colitis has been reported with nearly all antibacterial agents and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents.

Because antibiotic therapy has been associated with severe colitis, which may end fatally, it should be reserved for serious infections where less toxic antimicrobial agents are inappropriate, as described in the INDICATIONS AND USAGE section. It should not be used in patients with nonbacterial infections such as most upper respiratory tract infections. Treatment with antibacterial agents alters the normal flora of the colon and may permit over-growth of clostridia. Studies indicate that a toxin produced by Clostridium difficile is one primary cause of "antibiotic-associated colitis."

After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to drug discontinuation alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation, and treatment with an antibacterial drug that is clinically effective against C. difficile colitis.

Diarrhea, colitis, and pseudomembranous colitis have been observed to begin up to several weeks following cessation of therapy.

Tell your doctor if you have or have had:

• anemia
• pregnancy or are breast-feeding
• disease that has severely weakened you
• diabetes
• electrolyte imbalance
• vitamin B deficiency
• G6PD deficiency
• allergy to nitrofurantoin
• peripheral neuropathy (muscle weakness and atrophy, pain, and numbness)
• lung disease
• kidney disease

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

• If you plan to have any surgery, including dental, tell your doctor that you take this drug.
• Check with your doctor if there is no improvement within a few days.
• If using this drug for long-term therapy, have regular visits with your doctor to check your progress.
• You may experience rust-yellow or brown urine and/or temporary hair loss when you use this drug. You do not need to call your doctor if you experience these symptoms.

• Take this drug for the prescribed length of time. If you stop too soon, your symptoms could come back.
• If you miss a dose, take it as soon as you remember, but skip it if it is almost time for the next dose. Do not take double doses.
• Do not share your medication with others.
• Take the drug at the same time(s) each day.
• Take with food or milk.
• For oral liquid:
• Shake well before each dose.
• Use a specially marked measuring spoon or other device.
• The liquid may be mixed with water, milk, or fruit juices.
• For extended-release capsules:
• Do not break, chew, or crush long-acting forms of this drug.
• Store at room temperature with lid on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

Evaluations of Drug Interactions 2003 lists no drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods as causing “highly clinically significant” or “clinically significant” interactions when used together with the drugs in this section. We also found no interactions in the drugs’ FDA-approved professional package inserts. However, as the number of new drugs approved for marketing increases and as more experience is gained with these drugs over time, new interactions may be discovered.

antacids containing magnesium trisilicate, BENEMID, probenecid.

Call your doctor immediately if you experience:

• shortness of breath
• swelling of face, mouth, hands, or feet
• changes in facial skin color
• sudden trouble in swallowing or breathing
• hoarseness
• joint pain
• chills
• fever shortly after onset of therapy
• skin rash
• muscle pain
• itching
• hives
• chest pain
• cough
• general feeling of discomfort or illness
• sore throat
• unusual tiredness or weakness
• unusual bleeding or bruising
• pale or black, tarry stools
• blood in urine or stools
• pinpoint red spots on skin
• dizziness
• drowsiness
• headache
• burning, numbness, tingling, or painful sensations in arms, legs, hands, or feet
• weakness in arms, hands, legs, or feet
• wheezing or chest tightness
• sores, ulcer, or white spots on lips or in mouth
• swollen or painful glands
• appetite loss
• nausea or vomiting
• visual changes, blurred vision, or loss of vision, with or without eye pain
• blue skin color
• pale skin
• yellow eyes or skin
• dark urine
• continual severe abdominal or stomach pain or cramps
• continuous unpleasant breath odor
• vomiting blood
• severe watery diarrhea (may be bloody)
• confusion
• mental depression
• mood or mental changes
• blistering, peeling, or loosening of skin and mucous membranes
• red, thickened, or scaly skin
• red skin lesions, often with a purple center

Call your doctor if these symptoms continue:

• abdominal or stomach pain or upset
• diarrhea
• gas
• appetite loss
• nausea or vomiting
• headache

Call your doctor if these symptoms continue after you stop taking this drug:

• severe abdominal or stomach cramps or pain
• fever
• severe watery diarrhea (may be bloody)

Ask your doctor which of these tests should be done periodically while you are taking this drug:

• liver function tests
• kidney function tests
• lung function tests