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In the U.S.—

Furadantin Macrobid

Macrodantin

In Canada—

Apo-Nitrofurantoin Macrobid

Macrodantin Novo-Furantoin

• Antibacterial, systemic

Nitrofurantoin (nye-troe-fyoor-AN-toyn) belongs to the family of medicines called anti-infectives. It is used to treat infections of the urinary tract. It may also be used for other conditions as determined by your doctor.

Nitrofurantoin is available only with your doctor's prescription, in the following dosage forms:

Oral
• Capsules (U.S. and Canada)
• Extended-release Capsules (U.S. and Canada)
• Oral Suspension (U.S.)
• Tablets (U.S. and Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For nitrofurantoin, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to nitrofurantoin or to any related medicines such as furazolidone (e.g., Furoxone) or nitrofurazone (e.g., Furacin). Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Nitrofurantoin should not be used if you are within a week or 2 of your delivery date or during labor and delivery. It may cause problems in the infant. Studies in animals have shown some problems when given in doses many times the human dose. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding—Nitrofurantoin passes into the breast milk in small amounts and may cause problems in nursing babies, especially those with glucose-6-phosphate dehydrogenase (G6PD) deficiency. It may be necessary for you to take another medicine or to stop breast-feeding during treatment. Be sure you have discussed the risks and benefits of the medicine with your doctor.

Children—This medicine has been tested in children 1 month of age and older and, in effective doses, has not been shown to cause different side effects or problems in children than it does in adults. However, infants up to 1 month of age should not be given this medicine because they are especially sensitive to the effects of nitrofurantoin.

Older adults—Elderly people may be more sensitive to the effects of nitrofurantoin. This may increase the chance of side effects during treatment.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking nitrofurantoin, it is especially important that your health care professional know if you are taking any of the following:

• Acetohydroxamic acid (e.g., Lithostat) or
• Antidiabetics, oral (diabetes medicine you take by mouth) or
• Dapsone or
• Furazolidone (e.g., Furoxone) or
• Methyldopa (e.g., Aldomet) or
• Primaquine or
• Procainamide (e.g., Pronestyl) or
• Quinidine (e.g., Quinidex) or
• Sulfonamides (sulfa medicine) or
• Sulfoxone (e.g., Diasone) or
• Vitamin K (e.g., AquaMEPHYTON, Synkayvite)—Patients who take nitrofurantoin with any of these medicines may have an increase in side effects affecting the blood

• Carbamazepine (e.g., Tegretol) or
• Chloroquine (e.g., Aralen) or
• Cisplatin (e.g., Platinol) or
• Cytarabine (e.g., Cytosar-U) or
• Diphtheria, tetanus, and pertussis (DTP) vaccine or
• Disulfiram (e.g., Antabuse) or
• Ethotoin (e.g., Peganone) or
• Hydroxychloroquine (e.g., Plaquenil) or
• Lindane, topical (e.g., Kwell) or
• Lithium (e.g., Lithane) or
• Mephenytoin (e.g., Mesantoin) or
• Mexiletine (e.g., Mexitil) or
• Other anti-infectives by mouth or by injection (medicine for infection) or
• Pemoline (e.g., Cylert) or
• Phenytoin (e.g., Dilantin) or
• Pyridoxine (e.g., Hexa-Betalin) (with long-term, high-dose use) or
• Vincristine (e.g., Oncovin)—Patients who take nitrofurantoin with any of these medicines, or who have received a DTP vaccine within the last 30 days or are going to receive a DTP vaccine may have an increase in side effects affecting the nervous system

• Probenecid (e.g., Benemid) or
• Sulfinpyrazone (e.g., Anturane)—Patients who take nitrofurantoin with either of these medicines may have an increase in side effects

• Quinine (e.g., Quinamm)—Patients who take nitrofurantoin with quinine may have an increase in side effects affecting the blood and the nervous system

Other medical problems—The presence of other medical problems may affect the use of nitrofurantoin. Make sure you tell your doctor if you have any other medical problems, especially:

• Anemia or
• Diabetes mellitus or
• Lung disease or
• Nerve damage or
• Other serious illness or
• Vitamin B deficiency—These conditions may increase the chance for side effects

• Glucose-6-phosphate dehydrogenase (G6PD) deficiency—Nitrofurantoin may cause anemia in patients with G6PD deficiency

• Kidney disease (other than infection)—The chance of side effects of this medicine may be increased and the medicine may be less effective in patients with kidney disease

Do not give this medicine to infants up to 1 month of age.

Nitrofurantoin is best taken with food or milk. This may lessen stomach upset and help your body to better absorb the medicine.

For patients taking the oral liquid form of this medicine :

• Shake the oral liquid forcefully before each dose to help make it pour more smoothly and to be sure the medicine is evenly mixed.
• Use a specially marked measuring spoon or other device to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid.
• Nitrofurantoin may be mixed with water, milk, fruit juices, or infants' formulas. If it is mixed with any of these liquids, take the medicine immediately after mixing. Be sure to drink all the liquid in order to get the full dose of medicine.

For patients taking the extended-release capsule form of this medicine:

• Swallow the capsules whole.
• Do not open, crush, or chew the capsules before swallowing them.

To help clear up your infection completely, keep taking this medicine for the full time of treatment, even if you begin to feel better after a few days. Do not miss any doses.

Dosing—

The dose of nitrofurantoin will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of nitrofurantoin. If your dose is different, do not change it unless your doctor tells you to do so.

• For the capsule, oral suspension, and tablet dosage forms:
  • For the prevention of urinary tract infection:
    • Adults and adolescents—50 to 100 mg once a day at bedtime.
    • Children 1 month of age and older—Dose is based on body weight and must be determined by your doctor.
    • Children up to 1 month of age—Use is not recommended.
  • For the treatment of urinary tract infection:
    • Adults and adolescents—50 to 100 mg every six hours.
    • Children 1 month of age and older—Dose is based on body weight and must be determined by your doctor.
    • Children up to 1 month of age—Use is not recommended.
• For the extended-release capsule dosage form:
  • Adults and children 12 years of age and older: 100 mg every twelve hours for seven days.
  • Children up to 12 years of age: Dose must be determined by the doctor.

Missed dose—

If you do miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store the capsule or tablet form of this medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Keep the oral liquid form of this medicine from freezing.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

It is important that your doctor check your progress at regular visits if you will be taking this medicine for a long time.

If your symptoms do not improve within a few days, or if they become worse, check with your doctor.

For diabetic patients:

• This medicine may cause false test results with some urine sugar tests. Check with your doctor before changing your diet or the dosage of your diabetes medicine.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

• More common
  • Changes in facial skin color;  chest pain;  chills;  cough;  fever;  general feeling of discomfort or illness;  hives;  hoarseness ;  itching;  joint or muscle pain;  shortness of breath;  skin rash;  sudden trouble in swallowing or breathing ;  swelling of face, mouth, hands, or feet;  troubled breathing 
  
  

• Less common
  • Black, tarry stools;  blood in urine or stools;  burning, numbness, tingling, or painful sensations;  dizziness;  drowsiness;  headache;  pinpoint red spots on skin;  sore throat;  unusual bleeding or bruising;  unusual tiredness or weakness;  weakness in arms, hands, legs, or feet  
  
  

• Rare
  • Abdominal or stomach pain;  blistering, peeling, or loosening of skin and mucous membranes;  bluish color of skin;  blurred vision or loss of vision, with or without eye pain;  bulging fontanel in infants ;  confusion;  darkening of urine;  diarrhea, watery and severe, which may also be bloody;  loss of appetite;  mental depression;  mood or mental changes;  nausea or vomiting;  pale skin;  pale stools;  red skin lesions, often with a purple center;  red, thickened, or scaly skin ;  skin rash;  sores, ulcers, or white spots on lips or in mouth;  swollen or painful glands;  unpleasant breath odor;  visual changes;  vomiting of blood;  wheezing or tightness in chest;  yellow eyes or skin  
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Diarrhea;  gas 
  
  

After you stop using this medicine, your body may need time to adjust. The length of time this takes depends on the amount of medicine you were using and how long you used it. During this period of time check with your doctor immediately if you notice any of the following side effects:

• Abdominal or stomach cramps or pain, severe;  diarrhea, watery and severe, which may also be bloody;  fever 

This medicine may cause the urine to become rust-yellow to brown. This side effect does not require medical attention.

Nitrofurantoin may cause a temporary loss of hair in some people.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Revised: 06/14/1999