Nitrofurantoin
Nitrofurantoin Prescribing Information
Nitrofurantoin capsules, USP (macrocrystals) is specifically indicated for the treatment of urinary tract infections when due to susceptible strains of
Nitrofurantoin is not indicated for the treatment of pyelonephritis or perinephric abscesses.
To reduce the development of drug-resistant bacteria and maintain the effectiveness of nitrofurantoin capsules, USP (macrocrystals) and other antibacterial drugs, nitrofurantoin capsules, USP (macrocrystals) should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
Nitrofurantoins lack the broader tissue distribution of other therapeutic agents approved for urinary tract infections. Consequently, many patients who are treated with nitrofurantoin capsules, USP (macrocrystals) are predisposed to persistence or reappearance of bacteriuria. Urine specimens for culture and susceptibility testing should be obtained before and after completion of therapy. If persistence or reappearance of bacteriuria occurs after treatment with nitrofurantoin capsules, USP (macrocrystals), other therapeutic agents with broader tissue distribution should be selected. In considering the use of nitrofurantoin capsules, USP (macrocrystals), lower eradication rates should be balanced against the increased potential for systemic toxicity and for the development of antimicrobial resistance when agents with broader tissue distribution are utilized.
Nitrofurantoin capsules (macrocrystals) should be given with food to improve drug absorption and, in some patients, tolerance.
Therapy should be continued for one week or for at least 3 days after sterility of the urine is obtained. Continued infection indicates the need for reevaluation.
For long-term suppressive therapy in adults, a reduction of dosage to 50 to 100 mg at bedtime may be adequate. For long-term suppressive therapy in pediatric patients, doses as low as 1 mg/kg per 24 hours, given in a single dose or in two divided doses, may be adequate.
Anuria, oliguria, or significant impairment of renal function (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine) are contraindications. Treatment of this type of patient carries an increased risk of toxicity because of impaired excretion of the drug.
Because of the possibility of hemolytic anemia due to immature erythrocyte enzyme systems (glutathione instability), the drug is contraindicated in pregnant patients at term (38 to 42 weeks’ gestation), during labor and delivery, or when the onset of labor is imminent. For the same reason, the drug is contraindicated in neonates under one month of age.
Nitrofurantoin capsules, (macrocrystals) are contraindicated in patients with a previous history of cholestatic jaundice/ hepatic dysfunction associated with nitrofurantoin.
Nitrofurantoin capsules, (macrocrystals) are also contraindicated in those patients with known hypersensitivity to nitrofurantoin.
In subacute pulmonary reactions, fever and eosinophilia occur less often than in the acute form. Upon cessation of therapy, recovery may require several months. If the symptoms are not recognized as being drug-related and nitrofurantoin therapy is not stopped, the symptoms may become more severe.
Acute pulmonary reactions are commonly manifested by fever, chills, cough, chest pain, dyspnea, pulmonary infiltration with consolidation or pleural effusion on x-ray, and eosinophilia. Acute reactions usually occur within the first week of treatment and are reversible with cessation of therapy. Resolution often is dramatic (see
Changes in EKG (e.g., non-specific ST/T wave changes, bundle branch block) have been reported in association with pulmonary reactions.
Cyanosis has been reported rarely.
Asthenia, vertigo, nystagmus, dizziness, headache, and drowsiness also have been reported with the use of nitrofurantoin.
Benign intracranial hypertension (pseudotumor cerebri), confusion, depression, optic neuritis, and psychotic reactions have been reported rarely. Bulging fontanels, as a sign of benign intracranial hypertension in infants, have been reported rarely.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Antacids containing magnesium trisilicate, when administered concomitantly with nitrofurantoin, reduce both the rate and extent of absorption. The mechanism for this interaction probably is adsorption of nitrofurantoin onto the surface of magnesium trisilicate.
Uricosuric drugs, such as probenecid and sulfinpyrazone, can inhibit renal tubular secretion of nitrofurantoin. The resulting increase in nitrofurantoin serum levels may increase toxicity, and the decreased urinary levels could lessen its efficacy as a urinary tract antibacterial.
Nitrofurantoin macrocrystals, USP is a synthetic chemical of controlled crystal size. It is a stable, brown yellow, macrocrystalline compound. Nitrofurantoin macrocrystals, USP is an antibacterial agent for specific urinary tract infections. It is available in 25 mg, 50 mg, and 100 mg capsules for oral administration.
1-[[(5-NITRO-2-FURANYL)METHYLENE]AMINO]-2,4-IMIDAZOLIDINEDIONE
Inactive Ingredients: Lactose monohydrate, maize starch, corn starch and talc. The hard gelatin capsules contain gelatin, titanium dioxide, D&C Red No. 33 (50 mg and 100 mg capsules only) and D&C Yellow No. 10 (50 mg and 100 mg capsules only). The capsules are printed with edible black ink containing shellac, propylene glycol, potassium hydroxide and ferrosoferric oxide.
FDA approved dissolution specification differs from the USP dissolution specification.