Indications

Nitrofurantoin is specifically indicated for the treatment & prophylaxis of urinary tract infections when due to susceptible strains of Escherichia coli, Enterococci, Staphylococcus aureus, Staphylococcus saprophyticus and certain susceptible strains of Klebsiella and Enterobacter species.

Therapeutic Class

Systemic Urinary Anti- infective

Pharmacology

Nitrofurantoin interferes with cell metabolism and cell wall synthesis by inhibiting several enzyme systems including acetyl coenzyme A. It is bactericidal to most gram-positive and gram-negative urinary tract pathogens.

Dosage

Tablet:

Adults: 50-100 mg four times a day – the lower dosage level is recommended for uncomplicated urinary tract infections.

Children: 5-7 mg/kg/day in four divided doses (contraindicated under one month of age). Therapy should be continued for one week or for at least 3 days after sterility of the urine is obtained.

For long-term suppressive therapy in adults: a reduction of dosage to 50-100 mg at bedtime may be adequate. For long-term suppressive therapy in children, doses as low as 1 mg/kg per 24 hours, given in a single dose or in two divided doses, may be adequate.

SR Capsule:

Adults and Children over 12 years: One 100 mg capsule every 12 hours for seven days.

Genito-urinary surgical prophylaxis: One capsule twice daily on day of procedure and for next 3 days.

Suspension:

Children: 5-7 mg/kg/day in four divided doses (contraindicated under 1 month of age). The average dose of Nitrofurantoin suspension for pediatric patients can be calculated as follows:-

For 7 to 11 kg Body Weight patient: ½ (2.5 ml) teaspoonfuls (4 times daily)

For 12 to 21 kg Body Weight patient: 1 (5 ml) teaspoonfuls (4 times daily)

For 22 to 30 kg Body Weight patient: 1 ½ (7.5 ml) teaspoonfuls (4 times daily)

For 31 to 41 kg Body Weight patient: 2 (10 ml) teaspoonfuls (4 times daily)

Therapy should be continued for one week or for at least 3 days after sterility of the urine is obtained.

For long-term suppressive therapy in children, doses as low as 1 mg/kg per 24 hours, given in a single dose or in two divided doses, may be adequate.

Administration

Nitrofurantoin should be taken with food.

Interaction

Reduced excretion with probenecid or sulfinpyrazone. Absorption reduced by magnesium trisilicate. Antagonistic effects with quinolone antibacterials. Reduced effects with carbonic anhydrase inhibitors or urinary alkalinisers.

Contraindications

Anuria, oliguria, or significant impairment of renal function are contraindications. This drug is contraindicated in pregnant patients at 38-42 weeks, during labor and delivery. Nitrofurantoin is also contraindicated in those patients with known hypersensitivity to Nitrofurantoin

Side Effects

The most frequent clinical adverse events are nausea, headache, and flatulence. Other less occurred adverse events are diarrhea, dyspepsia, abdominal pain, constipation, emesis, dizziness, drowsiness

Pregnancy & Lactation

Pregnancy Category B. There are no adequate and well-controlled studies in pregnant women. This drug should be used during pregnancy only if clearly needed.

Nitrofurantoin has been detected in human breast milk in trace amounts. Because of the potential for serious adverse reactions from Nitrofurantoin in nursing infants under one month of age, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother

Precautions & Warnings

If acute, sub-acute, or chronic pulmonary reactions occur, Nitrofurantoin should be discontinued. Antacid preparations containing magnesium trisilicate should not be taken while taking Nitrofurantoin

Overdose Effects

Occasional incidents of acute overdosage of Nitrofurantoin have not resulted in any specific symptoms other than vomiting. Induction of emesis is recommended

Storage Conditions

Store at 15-30° C