Nitrofurantoin
Brand Names: Macrodantin, Macrobid, Furadantin
Generic Available
Common Dosage Forms:
Macrodantin Capsules: 25 mg, 50 mg, 100 mg macrodantin macrocrystals
Macrobid Capsules: 100 mg nitrofurantoin in the form of 25 mg of nitrofurantoin macrocrystals, 75 mg nitrofurantoin monohydrate
Furantoin Suspension: 25 mg/5 mL
FDA Indications/Dosages:
Infections of the urinary tract due to susceptible strains of E. coli enterococci, S. aureus, and certain susceptible strains of Klebsiella, Enterobacter, and Proteus species (Macrodantin only): 50-100 mg given four times a day with food. 50-100 mg at bedtime may be adequate for long-term suppressive therapy in adults.
Children (over 1 month of age): 5-7 mg/kg/day given in four divided doses with food.
Treatment of acute uncomplicated urinary tract infections caused by susceptible strains of Escherichia coli or Staphylococcus saprophyticus (Macrobid only): One 100 mg capsule every 12 hours for 7 days.
Pharmacology/Pharmacokinetics: Nitrofurantoin’s mechanism of action may be due to an inhibition of acetyl-coenzyme A, interfering with the metabolism of carbohydrates in susceptible bacteria. Nitrofurantoin macrocrystals dissolve slower than nitrofurantoin monohydrate. The nitrofurantoin monohydrate in Macrobid is contained in a powder blend which, upon exposure to gastric and intestinal fluids, forms a gel matrix that releases nitrofurantoin over time. Urinary excretion of both products is similar.
Drug Interactions: Magnesium salts may decrease effectiveness.
Contraindications/Precautions: Contraindicated in patients with anuria, oliguria, significantly impaired renal function, in pregnant patients at term, and in infants under one month of age. Use with caution in patients with glucose-6-phosphate deficiency, peripheral neuropathy, or pulmonary disease. Acute, subacute, or chronic pulmonary reactions have been observed in patients treated with nitrofurantoin for over 6 months. Close monitoring of patients is advised. Cases of Clostridium difficile associated diarrhea have occurred during treatment with nitrofurantoin. Persistent or severe diarrhea should be reported to a physician. No Pregnancy Category Established.
Adverse Effects: Nausea, headache, flatulence, vomiting, diarrhea, fever, coughs, and chills.
Patient Consultation:
Complete full course of therapy unless otherwise directed.
Take with food to enhance absorption.
Take at evenly spaced intervals around the clock.
Shake suspension well before use.
May cause discoloration of the urine (rare).
Store in a cool, dry place away from sunlight and children.
Contact a physician if the above side effects are severe or persistent.
If a dose is missed, skip it and return to normal dosing schedule.