Nostiriazyn (Nitrofurantoin)

Nitrofurantoin is a nitrofuran antibiotic that concentrates in the urine and is used to treat infections of the urinary tract caused by susceptible bacteria.

• Uncomplicated urinary tract infection: eradicates susceptible bacteria, relieving symptoms and preventing progression.
• Acute cystitis: provides rapid bacterial clearance in bladder infection, improving patient comfort.
• Recurrent urinary tract infection prophylaxis: reduces the incidence of repeat infections when used as a preventive regimen.
• Pyelonephritis (uncomplicated): may be used as an alternative when other agents are unsuitable, targeting kidney infection.
• Urinary prophylaxis in patients with structural abnormalities: helps prevent infection recurrence in individuals with predisposing urinary tract conditions.

• Nitrofurantoin inhibits bacterial enzymes involved in carbohydrate metabolism, disrupting the synthesis of essential macromolecules and leading to bacterial cell death. The drug is concentrated in the urinary tract, where it exerts its antibacterial effect against susceptible Gram‑negative and Gram‑positive organisms.

Nitrofurantoin may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Nausea: mild stomach upset that may resolve spontaneously, sometimes accompanied by a feeling of queasiness.
• Vomiting: sudden expulsion of stomach contents, usually brief but can lead to dehydration if persistent.
• Diarrhea: loose stools that can lead to dehydration if severe, often accompanied by abdominal cramping.
• Headache: mild to moderate head pain, often transient and may improve with rest or hydration.

Serious or Rare Side Effects

• Pulmonary toxicity (interstitial pneumonitis): inflammation of lung tissue that may cause persistent cough, breathlessness, and reduced oxygen exchange, requiring medical evaluation.
• Hepatic injury: elevated liver enzymes or jaundice indicating liver stress, which may progress to hepatitis if not monitored.
• Severe allergic reactions (anaphylaxis): rapid onset of hives, swelling, and difficulty breathing, potentially leading to shock and requiring immediate emergency treatment.

Before prescribing Nitrofurantoin, several safety considerations should be reviewed to minimize risk.

• Renal function: assess glomerular filtration rate before initiating therapy, adjust or avoid if impaired.
• Pregnancy: use only when clearly indicated, as safety data are limited during the first trimester.
• G6PD deficiency: avoid due to risk of hemolytic anemia in susceptible individuals.
• Elderly patients: monitor renal clearance closely, as reduced function may increase drug accumulation.
• Drug interactions: review concomitant medications for potential absorption or toxicity issues.
• Store at below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Nitrofurantoin can interact with other medicines, affecting its absorption or toxicity profile.

Major Interactions (Avoid)

• Antacids containing magnesium or aluminum: significantly reduce oral absorption, decreasing efficacy.
• Probenecid: decreases renal excretion, increasing systemic exposure and risk of adverse effects.

Moderate Interactions (Monitor Closely)

• Warfarin: may enhance anticoagulant effect, requiring closer INR monitoring.
• Diuretics: can increase risk of crystalluria, necessitating adequate hydration.
• High-dose vitamin C: may alter urinary pH, affecting drug activity.