Nitrofurantoin Aspire Pharma (Nitrofurantoin)

Nitrofurantoin is used to treat infections of the urinary tract caused by susceptible bacteria.

• Uncomplicated urinary tract infection (cystitis): clears bacterial infection and relieves symptoms such as dysuria and frequency.
• Acute uncomplicated lower urinary tract infection: provides bactericidal activity against common uropathogens, shortening disease duration.
• Prophylaxis of recurrent urinary tract infections: reduces recurrence rate by maintaining low urinary bacterial counts.
• Urinary tract infection caused by Escherichia coli: achieves eradication of E. coli strains susceptible to nitrofurantoin.

• Nitrofurantoin exerts its antibacterial effect by inhibiting bacterial enzymes involved in carbohydrate metabolism, particularly the bacterial nitrofuran reductases. This disruption interferes with the synthesis of essential macromolecules, leading to impaired cell wall formation and bacterial cell death. The drug is concentrated in the urine, providing high local concentrations that target uropathogens while minimizing systemic exposure. It remains active against many strains resistant to other oral agents, making it useful for first‑line therapy.

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

Common Side Effects

• Nausea: mild stomach upset often occurring early in therapy.
• Loss of appetite: reduced desire to eat during treatment.
• Headache: transient head discomfort reported by some patients.
• Diarrhea: loose stools that usually resolve without intervention.
• Metallic taste: temporary alteration of taste sensation.
• Skin rash: mild erythema or itching.

Serious or Rare Side Effects

• Pulmonary toxicity: interstitial lung disease or acute respiratory distress that may require discontinuation.
• Hepatic injury: elevated liver enzymes or hepatitis.
• Severe allergic reactions: anaphylaxis or angioedema.
• Hemolytic anemia in G6PD deficiency: rapid destruction of red blood cells.
• Peripheral neuropathy: numbness or tingling in extremities.
• Stevens‑Johnson syndrome or toxic epidermal necrolysis: life‑threatening skin reactions.

Before prescribing nitrofurantoin, clinicians should consider several safety factors to minimize risk.

• Renal function assessment: evaluate creatinine clearance to ensure adequate drug excretion.
• Pregnancy: avoid use unless benefits outweigh potential risks, as safety data are limited.
• G6PD deficiency: contraindicated due to risk of hemolytic anemia.
• Severe renal impairment: do not use in patients with markedly reduced kidney function because efficacy is compromised.
• Drug interactions: review concomitant medications that may affect absorption or increase toxicity.
• Store at ambient temperature: keep in original packaging, protect from moisture and heat.

Nitrofurantoin can interact with other medicines, altering its absorption or increasing adverse effects.

Major Interactions (Avoid)

• Antacids containing magnesium or aluminum: markedly reduce nitrofurantoin absorption.
• Probenecid: decreases renal clearance, raising nitrofurantoin plasma levels and toxicity risk.

Moderate Interactions (Monitor Closely)

• Warfarin: may potentiate anticoagulant effect, requiring INR monitoring.
• Fluoroquinolones: combined use may increase risk of tendonitis or tendon rupture.
• High‑dose vitamin C: can acidify urine and affect nitrofurantoin activity.