Overview
11 DESCRIPTION Nitrofurantoin Oral Suspension, USP contains nitrofurantoin, a synthetic nitrofuran antibacterial agent specific for urinary tract infections. The chemical name is 1-[[(5-nitro-2-furanyl)methylene]amino]-2,4imidazolidinedione monohydrate. The molecular formula is C8H6N4O5·H2O and the molecular weight is 256.17.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Nitrofurantoin is an antibacterial drug [ see Microbiology (12.4)] . 12.2 Pharmacodynamics Pharmacodynamic effects of nitrofurantoin are unknown. 12.3 Pharmacokinetics Absorption Orally administered nitrofurantoin is readily absorbed. Blood concentrations at therapeutic dosage are usually low. Effect of Food The presence of food or agents delaying gastric emptying can increase the bioavailability of nitrofurantoin. Distribution Nitrofurantoin is highly soluble in urine. Nitrofurantoin lacks the broader tissue distribution of other therapeutic agents approved for urinary tract infections. Elimination Excretion Nitrofurantoin is rapidly excreted in urine, to which it may impart a brown color.
Indications
- 1 INDICATIONS & USAGE Nitrofurantoin is indicated in adults and pediatric patients 1 month of age and older for the treatment of urinary tract infections due to susceptible strains of Escherichia coli , Enterococcus species, Staphylococcus aureus , Klebsiella species and Enterobacter species. Limitations of Use Nitrofurantoin is not indicated for the treatment of pyelonephritis or perinephric abscesses [see Warnings and Precautions (5.7)].
Common Doses
- 50 mg
- 100 mg
- 5 mg
- 7 mg
Dosage
2 DOSAGE & ADMINISTRATION Adult Patients: 50 mg to 100 mg four times a day -the lower dosage level is recommended for uncomplicated urinary tract infections. (2.2) Pediatric Patients: 5 mg/kg to 7 mg/kg of body weight per 24 hours, given in four divided doses (contraindicated under one month of age). (2.3) 2.1 Recommended Dosage and Administration in Adult Patients The recommended dosage is 50 mg to 100 mg of nitrofurantoin four times a day. For long-term suppressive therapy in adults, a reduction of dosage to 50 mg to 100 mg at bedtime may be adequate .
Contraindications
- 4 CONTRAINDICATIONS Nitrofurantoin is contraindicated in: patients with known hypersensitivity to nitrofurantoin [see Warnings and Precautions (5.1)]. patients with a previous history of cholestatic jaundice/hepatic dysfunction associated with nitrofurantoin [see Warnings and Precautions (5.3)]. patients who have anuria, oliguria, or significant impairment of renal function (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine) due to an increased risk of toxicity resulting from impaired excretion of the drug [see Warnings and Precautions (5.4)].
Side Effects
- 6 ADVERSE REACTIONS The following clinically significant adverse reactions are discussed in more detail in other sections of the labeling: Hypersensitivity Reactions [see Warnings and Precautions (5.1)] Pulmonary Reactions [see Warnings and Precautions (5.2)] Hepatotoxicity [see Warnings and Precautions (5.3)] Neuropathy [see Warnings and Precautions (5.4)] Hemolytic anemia [see Warnings and Precautions (5.5)] Clostridioides difficile -associated Diarrhea [see Warnings and Precautions (5.6)] Persistence or Reappearance of Bacteriuria [see Warnings and Precautions (5.
Interactions
- 7 DRUG INTERACTIONS Antacids : Decreased absorption of nitrofurantoin. (7.1) Uricosuric drugs: Inhibit renal tubular secretion of nitrofurantoin. (7.2) 7.1 Antacids 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. If coadministration of nitrofurantoin with antacids containing magnesium trisilicate cannot be avoided, monitor for lack of efficacy [see Clinical Pharmacology (12.3)] . 7.