Nitrofurantoin Orifarm (Nitrofurantoin)

Nitrofurantoin is used to treat infections of the urinary tract by targeting common uropathogens.

• Uncomplicated urinary tract infections: provides bactericidal activity that eradicates the causative bacteria.
• Cystitis: clears infection and relieves urinary symptoms.
• Lower urinary tract infections: effective against Escherichia coli and other typical urinary pathogens.

• Nitrofurantoin is reduced by bacterial flavoproteins to reactive intermediates that bind bacterial DNA and inhibit carbohydrate metabolism, leading to bactericidal activity against susceptible urinary pathogens while sparing most host cells.

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

Common Side Effects

• Nausea: mild to moderate upset stomach.
• Diarrhea: loose stools that may be transient.
• Headache: occasional mild headache during therapy.
• Loss of appetite: reduced desire to eat.
• Metallic taste: transient alteration of taste perception.

Serious or Rare Side Effects

• Pulmonary toxicity: interstitial lung disease or acute respiratory distress.
• Hepatic injury: elevated liver enzymes or hepatitis.
• Severe allergic reactions: rash, Stevens‑Johnson syndrome, or anaphylaxis.
• Hemolytic anemia: especially in patients with G6PD deficiency.
• Peripheral neuropathy: numbness or tingling in extremities.

Before prescribing Nitrofurantoin, clinicians should consider several safety factors.

• Renal function: avoid or adjust dose in patients with impaired renal clearance.
• Pregnancy: safety category unknown; use only if benefits outweigh risks.
• G6PD deficiency: risk of hemolysis; contraindicated in affected individuals.
• Elderly patients: monitor for pulmonary and hepatic toxicity.
• Concomitant antacids: may reduce absorption; separate administration by at least 2 hours.
• Store at room temperature: keep in the original pack, protect from moisture.

Nitrofurantoin can interact with other medicines, altering its effectiveness or safety.

Major Interactions (Avoid)

• Antacids containing magnesium or aluminum: markedly reduce absorption.
• Probenecid: increases nitrofurantoin plasma levels, raising toxicity risk.
• Warfarin: may potentiate anticoagulant effect and raise INR.
• Oral contraceptives: possible reduction in contraceptive efficacy.

Moderate Interactions (Monitor Closely)

• NSAIDs: combined use may worsen renal function.
• Allopurinol: may increase risk of hypersensitivity reactions.
• Methenamine: concurrent use can diminish antimicrobial activity.