Nitrofurantoin

Mechanism :

Nitrofurantoin is an antibacterial agent specific for urinary tract infections and is bactericidal in urine at therapeutic doses. The mechanism of the antimicrobial action of nitrofurantoin is unusual. Nitrofurantoin is reduced by bacterial flavoproteins to reactive intermediates which alter bacterial ribosomal proteins, and other macromolecules. As a result of such inactivation’s, the vital biochemical processes of protein synthesis, aerobic energy metabolism, DNA synthesis, RNA synthesis, and cell wall synthesis are inhibited.

Indication :

• Urinary tract infection - treatment and prophylaxis
• Vesico-ureteric reflux - conservative treatment

Contraindications :

Anuria, oliguria, or significant impairment of renal function are contraindications. Treatment of this type of patient carries an increased risk of toxicity because of impaired excretion of the drug. The drug is contraindicated in pregnant patients at term (38-42 weeks gestation), during labor and delivery, or when the onset of labor is imminent and in neonates under three months of age, and in those patients with known hypersensitivity to nitrofurantoin.

Dosing :

Adverse Effect :

Nausea, anorexia, clostridium difficile colitis, flatulence, vomiting, abdominal pain, diarrhea, acute and chronic pulmonary reactions, rarely cholestatic jaundice and hepatitis, increased LFT, peripheral neuropathy (rare), numbness, paresthesias, agranulocytosis, haemolytic anemia, thrombocytopenia, G6PD deficiency, megaloblastic anemia, leukopenia, granulocytopenia and eosinophilia, allergic skin reactions including pruritus; exfoliative dermatitis and erythema.

Interaction :

Antacids Containing Magnesium Trisilicate: Reduce both the rate and extent of absorption
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.
A false-positive reaction for glucose in the urine may occur. This has been observed with Benedict’s and Fehling’s solutions but not with the glucose enzymatic test.

Renal Dose :

Hepatic Dose :