Nitrofurantoin

Nitrofurantoin

Drug monograph · NCLEX study reference
Trade names	Macrobid
Therapeutic class	Urinary antibacterial
Pharmacologic class	Nitrofuran
Onset / peak / duration	Acts in the urinary tract; twice daily (macrocrystal).
Half-life / level	Short; no routine level.
Routes	PO (oral)
High-alert (ISMP)	No
Black box warning	None
Antidote / reversal	Supportive care.
Pregnancy / lactation	Avoid near term.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Nitrofurantoin (brand name Macrobid) — Urinary antibacterial; Nitrofuran.

Identification

• Therapeutic class: Urinary antibacterial.
• Pharmacologic class: Nitrofuran.

Pharmacology

• Mechanism of action: Damages bacterial DNA and proteins; concentrates in urine.
• Onset / peak / duration: Acts in the urinary tract; twice daily (macrocrystal).
• Half-life / therapeutic level: Short; no routine level.

Clinical use

• Indications: Uncomplicated urinary tract infection, UTI prophylaxis.
• Usual dose, route, frequency: 100 mg PO twice daily with food.
• Maximum dose / adjustments: Avoid when creatinine clearance is low (inadequate urinary levels and toxicity risk).

Safety

• Contraindications: Significant renal impairment, late pregnancy (38 weeks onward), infants under 1 month, G6PD deficiency.
• Black box warning: None.
• Interactions: Antacids with magnesium (reduce absorption), probenecid.
• Pregnancy / lactation: Avoid near term.
• High-alert: No.

Adverse effects

• Common side effects: Nausea, headache, brown discoloration of urine.
• Serious effects to report: Acute and chronic pulmonary toxicity (cough, dyspnea), hepatotoxicity, peripheral neuropathy, hemolysis in G6PD deficiency.
• Antidote / reversal: Supportive care.

Nursing process

• Assessment before administration: Renal function, pregnancy status, G6PD if known, respiratory baseline.
• Interventions during therapy: Give with food; assess respiratory symptoms with long-term use.
• Monitor: Respiratory and neuro status, infection resolution.
• Evaluation / expected outcome: Resolution of urinary infection.

Patient teaching

• Patient teaching: Harmless brown urine; take with food; report cough or breathing trouble.
• Notify provider if: Cough or shortness of breath, numbness, yellowing of skin.
• Administration tips: With food; only for urinary infections, not systemic.