Nitrofurantoin (monohydrate/macrocrystals)

INDICATIONS AND USAGE Nitrofurantoin capsules, USP (monohydrate/macrocrystals) are indicated only for the treatment of acute uncomplicated urinary tract infections (acute cystitis) caused by susceptible strains of Escherichia coli or Staphylococcus saprophyticus. 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 capsule, USP (monohydrate/macrocrystals) and other antibacterial drugs, nitrofurantoin capsule, USP (monohydrate/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 (monohydrate/macrocrystals) are predisposed to persistence or reappearance of bacteriuria. (See CLINICAL STUDIES. ) 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 (monohydrate/macrocrystals) other therapeutic agents with broader tissue distribution should be selected. In considering the use of nitrofurantoin capsules, USP (monohydrate/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.

DOSAGE AND ADMINISTRATION: Nitrofurantoin capsules (monohydrate/macrocrystals) should be taken with food. Adults and Pediatric Patients Over 12 Years : One 100 mg capsule every 12 hours for seven days.

CONTRAINDICATIONS: 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 (monohydrate/macrocrystals) are contraindicated in patients with a previous history of cholestatic jaundice/hepatic dysfunction associated with nitrofurantoin. Nitrofurantoin capsules (monohydrate/macrocrystals) are also contraindicated in those patients with known hypersensitivity to nitrofurantoin.

ADVERSE REACTIONS In clinical trials of nitrofurantoin capsules (monohydrate/macrocrystals), the most frequent clinical adverse events that were reported as possibly or probably drug-related were nausea (8%), headache (6%), and flatulence (1.5%). Additional clinical adverse events reported as possibly or probably drug-related occurred in less than 1% of patients studied and are listed below within each body system in order of decreasing frequency: Gastrointestinal: Diarrhea, dyspepsia, abdominal pain, constipation, emesis Neurologic: Dizziness, drowsiness, amblyopia Respiratory: Acute pulmonary hypersensitivity reaction (see Error! Hyperlink reference not valid. ) Allergic: Pruritus, urticaria Dermatologic: Alopecia Miscellaneous: Fever, chills, malaise The following additional clinical adverse events have been reported with the use of nitrofurantoin: Gastrointestinal: Sialadenitis, pancreatitis. There have been sporadic reports of pseudomembranous colitis with the use of nitrofurantoin. The onset of pseudomembranous colitis symptoms may occur during or after antimicrobial treatment. (See Error! Hyperlink reference not valid. .) Neurologic: Peripheral neuropathy, which may become severe or irreversible, has occurred. Fatalities have been reported. Conditions such as renal impairment (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine), anemia, diabetes mellitus, electrolyte imbalance, vitamin B deficiency, and debilitating diseases may increase the possibility of peripheral neuropathy. (See Error! Hyperlink reference not valid. .) Asthenia, vertigo, and nystagmus 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. Respiratory: CHRONIC, SUBACUTE, OR ACUTE PULMONARY HYPERSENSITIVITY REACTIONS MAY OCCUR WITH THE USE OF NITROFURANTOIN. CHRONIC PULMONARY REACTIONS GENERALLY OCCUR IN PATIENTS WHO HAVE RECEIVED CONTINUOUS TREATMENT FOR SIX MONTHS OR LONGER. MALAISE, DYSPNEA ON EXERTION, COUGH, AND ALTERED PULMONARY FUNCTION ARE COMMON MANIFESTATIONS WHICH CAN OCCUR INSIDIOUSLY. RADIOLOGIC AND HISTOLOGIC FINDINGS OF DIFFUSE INTERSTITIAL PNEUMONITIS OR FIBROSIS, OR BOTH, ARE ALSO COMMON MANIFESTATIONS OF THE CHRONIC PULMONARY REACTION. FEVER IS RARELY PROMINENT. THE SEVERITY OF CHRONIC PULMONARY REACTIONS AND THEIR DEGREE OF RESOLUTION APPEAR TO BE RELATED TO THE DURATION OF THERAPY AFTER THE FIRST CLINICAL SIGNS APPEAR. PULMONARY FUNCTION MAY BE IMPAIRED PERMANENTLY, EVEN AFTER CESSATION OF THERAPY. THE RISK IS GREATER WHEN CHRONIC PULMONARY REACTIONS ARE NOT RECOGNIZED EARLY. 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 Error! Hyperlink reference not valid. .) 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. Hepatic : Hepatic reactions, including hepatitis, cholestatic jaundice, chronic active hepatitis, and hepatic necrosis, occur rarely. (See Error! Hyperlink reference not valid. .) Allergic : Lupus-like syndrome associated with pulmonary reaction to nitrofurantoin has been reported. Also, angioedema; maculopapular, erythematous, or eczematous er …

Drug Interactions 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.

DESCRIPTION: Nitrofurantoin is an antibacterial agent specific for urinary tract infections. Nitrofurantoin capsule, USP (monohydrate/macrocrystals) is hard gelatin capsule. Each capsule contains 100 mg of nitrofurantoin in the form of 25 mg of nitrofurantoin macrocrystals, USP and 75 mg of nitrofurantoin monohydrate, USP. The chemical name of nitrofurantoin macrocrystals, USP is 2,4-Imidazolidinedione, 1-[[(5-nitro-2-furanyl)methylene]-amino]. The chemical structure is the following: Molecular Weight: 238.16 Molecular formula: C 8 H 6 N 4 O 5 The chemical name of nitrofurantoin monohydrate, USP is 2,4-Imidazolidinedione, 1-[[(5-nitro-2-furanyl)methylene]-amino]-monohydrate. The chemical structure is the following: Molecular Weight: 256.18 Molecular formula: C 8 H 6 N 4 O 5 · H 2 O Inactive Ingredients: Each capsule contains carbomer homopolymer type B, corn starch, D&C Yellow No. 10, FD&C Blue No.1, FD&C Red No. 40, FD&C Red No. 3, gelatin, lactose monohydrate, magnesium stearate, potassium hydroxide, povidone K 30, povidone K 90, shellac, sucrose, talc, and titanium dioxide. FDA approved dissolution test specifications differ from USP Chemical structure diagram showing a compound with a nitro-substituted furan ring linked via an azomethine group to a hydantoin moiety. Key elements include oxygen, nitrogen atoms, double bonds, and c Chemical structure diagram showing a molecular compound with a nitro-substituted furan ring connected to a hydantoin moiety, including a water molecule indicated by ·H2O. Key elements include oxygen,

OVERDOSAGE: Occasional incidents of acute overdosage of nitrofurantoin have not resulted in any specific symptoms other than vomiting. Induction of emesis is recommended. There is no specific antidote, but a high fluid intake should be maintained to promote urinary excretion of the drug. Nitrofurantoin is dialyzable.

HOW SUPPLIED Nitrofurantoin capsules, USP (monohydrate/macrocrystals), 100 mg, are supplied as a Light yellow to yellow powder blend and yellow colored tablet filled in the hard gelatin capsule shell size '1' with black cap imprinted '100' and yellow colored body imprinted '102'. NDC 76420-884-07 bottle of 7 (repackaged from 59746-762-XX) NDC 76420-884-10 bottle of 10 (repackaged from 59746-762-XX) NDC 76420-884-12 bottle of 12 (repackaged from 59746-762-XX) NDC 76420-884-14 bottle of 14 (repackaged from 59746-762-XX) NDC 76420-884-20 bottle of 20 (repackaged from 59746-762-XX) NDC 76420-884-28 bottle of 28 (repackaged from 59746-762-XX) NDC 76420-884-30 bottle of 30 (repackaged from 59746-762-XX) NDC 76420-884-60 bottle of 60 (repackaged from 59746-762-XX) NDC 76420-884-90 bottle of 90 (repackaged from 59746-762-XX) NDC 76420-884-01 bottle of 100 (relabeled from 59746-762-01) NDC 76420-884-00 bottle of 1000 (relabeled from 59746-762-36) Store at controlled room temperature (59° to 86°F or 15° to 30°C). Rx Only