Nitrofurantoin
Urinary Anti-infective · Nitrofuran
Indications
Urinary-tract infections.
Dosage
Acute uncomplicated infection: Adults: 50 mg every 6 hr with food for 7 days (3 days usually adequate in women). Severe chronic recurrent infection: Adults: 100 mg every 6 hr with food for 7 days (dose reduced or discontinued if severe nausea). Children: Under 3 mth, not recommended. 3 mth-12 yr, 750 mcg/kg 4 times daily for 3-7 days; 12-18 yr, 50 mg 4 times daily for 3-7 days; increased to 100 mg 4 times daily in severe chronic recurrent infections. Prophylaxis of urinary-tract infection: Adults: 50-100 mg once daily at night. Children: 3 mth-11 yrs: 1 mg/kg once daily at night. 12-17 yrs: 50-100 mg once daily at night.
Adverse Effects
Anorexia, nausea, vomiting and diarrhoea; acute and chronic pulmonary reactions (pulmonary fibrosis reported; possible association with lupus erythematosus-like syndrome); peripheral neuropathy; also reported, hypersensitivity reactions (including angioedema, anaphylaxis, sialadenitis, urticaria, rash and pruritus); rarely, cholestatic jaundice, hepatitis, exfoliative dermatitis, erythema multiforme, pancreatitis, arthralgia, blood disorders (including agranulocytosis, thrombocytopenia and aplastic anaemia), benign intracranial hypertension and transient alopecia. Stevens-Johnson syndrome.
Risk Factor (Pregnancy/Lactation)
Pregnancy: No evidence of risk in humans. Lactation: Contraindicated or not recommended. Contraindications: Infants less than 3 months old, G6PD deficiency; acute porphyria. Renal impairment (eGFR <45mL/min/1.73m2 but may be used for 3-7 days if multidrug resistant lower UTI suspected and eGFR 30-44mL/min/1.73m2 if benefits outweigh risks). Precautions: Anaemia; diabetes mellitus; electrolyte imbalance; vitamin B and folate deficiency; pulmonary disease; on long-term therapy, monitor liver function and monitor for pulmonary symptoms, especially in the elderly (discontinue if deterioration in lung function); susceptibility to peripheral neuropathy; false positive urinary glucose (if tested for reducing substances); urine may be coloured yellow or brown.
Interactions
Oral magnesium salts, nalidixic acid, probenecid, sulfinpyrazone, magnesium trisilicate, quinolones, typhoid vaccine, carbonic anhydrase inhibitors, alkalising agents.
Advice to Patient
Take with meals or milk. Shake oral suspension well before measuring dose. Inform prescriber about severe diarrhoea and if it remains more than 3 days. After 2 or more months of therapy, watery or bloody stools can occur and can be serious, requiring immediate treatment. Contact prescriber immediately if condition does not improve or if rash, swelling of tongue, face, mouth, throat, tightness of chest occur or if condition gets worsened. Avoid taking preparations containing magnesium trisilicate during therapy. Complete full course of therapy even if you feel better. Take adequate amount of fluids (2-3 L per day) unless restricted by prescriber. During therapy urine color may change to brown, orange, or rust.
Pharmacokinetics
Absorption: Well absorbed; macrocrystalline form absorbed more slowly due to slower dissolution. Metabolism: Body tissues (except plasma) metabolize 60% of drug to inactive metabolites. Bioavailability: Increased with meals by approx. 40%. Half-life elimination: 20-60 mins. Excretion: Susp: Urine (approx. 40%). Faeces (small amounts). Macrocrystals: Urine (20%-25%).
Brands with this active ingredient
Compiled by Healify Pharmacy from published drug references. How we compile it →
Always consult a pharmacist or doctor.