Brand Name : FURANTIN
Generic Name : Nitrofurantoin
Preparations : 50 mg / 100 mg Tablets
Pharmacological Categories : Antibiotic, Urinary Antiseptic

Mechanism of Action (MOA)
FURANTIN (Nitrofurantoin) is reduced by the bacterial flavoproteins to reactive intermediates, which interfere with energy metabolism, and the production of bacterial proteins, DNA, RNA and cell walls.


  • Absorption : Readily absorbed from the gastrointestinal tract
  • Bioavailability : Increases with food
  • Protein Binding : 60 to 90%
  • Distribution : Crosses placenta, blood brain barrier and traces have been detected in breast milk
  • Metabolism : Liver and most body tissues
  • Elimination Half-life : 20 minutes to 1 hour; prolonged with renal impairment
  • Excretion : Urine and faeces (small amounts)

Indications and Dosage

  • Uncomplicated Lower Urinary Tract Infections : FURANTIN 50 to 100 mg four times daily for 7 days or for 3 days or more than 3 days after urine becomes sterile
  • Prophylaxis or Long-term Suppressive Therapy in Recurrent Infection : FURANTIN 50 to 100 mg at bedtime for up to 12 months

Side Effects
MOST COMMON : Nausea, vomiting, anorexia, abdominal pain
REPORTED : Anaphylaxis, erythema multiforme, Stevens-Johnson syndrome, exfoliative dermatitis, pancreatitis, a lupus-like syndrome, myalgia, and arthralgia, transient alopecia
RARE : Hepatotoxicity
MAY OCCUR : Neurological side effects like headache, drowsiness, vertigo, dizziness, nystagmus, benign intracranial hypertension, hypersensitivity reactions like skin rashes, urticaria, pruritus, fever, sialadenitis and angioedema
Note : Nitrofurantoin may cause a brownish discoloration of the urine.

Hypersensitivity to nitrofurantoin, renal impairment (anuria, oliguria, or creatinine clearance under 60 ml per minute), history of hepatic dysfunction / cholestatic jaundice with nitrofurantoin, glucose-6-phosphate dehydrogenase (G6PD) deficiency, pregnancy at term (38 to 42 weeks gestation), during labor and delivery, or when the onset of labor is imminent

Warnings / Precautions
Peripheral neuropathy, pulmonary toxicity, superinfection, monitor hepatic and pulmonary function during prolonged therapy, anemia, diabetes mellitus, electrolytes imbalance, debility, vitamin B deficiency, renal / hepatic disorder, glucose-6-phosphate dehydrogenase (G6PD) deficiency, elderly, children less than 1 month of age

Drug Interactions

  • Aluminium hydroxide, magnesium trisilicate decreases level of nitrofurantoin by inhibition of gastrointestinal absorption.
  • Nitrofurantoin will increase the level of digoxin by altering intestinal flora.
  • Calcium carbonate decreases the level of nitrofurantoin by inhibition of gastrointestinal absorption.
  • Quinolone antibacterials have antagonistic effects with nitrofurantoin.
  • Probenecid, sulfinpyrazone reduces excretion of nitrofurantoin.
  • Effects of nitrofurantoin may be decreased in the presence of carbonic anhydrase inhibitors and other drugs that alkalinize the urine.

FURANTIN 50 mg : A box of 20 blisters, each blister of 10 tablets
FURANTIN 100 mg : A box of 20 blisters, each blister of 10 tablets