Class: Nitrofuran Antibiotic
Dosage Forms. Capsule: 25 mg, 50 mg, 100 mg; Suspension: 5 mg/mL; Extended-Release Capsule: 100 mg
Common FDA Label Indication, Dosing, and Titration.
1. Urinary tract infection treatment: Adults, 50-100 mg po qid × 7 d; Children 1 mo and older, 5-7 mg/kg/d po × 7 d
2. Urinary tract infection prophyalxis: Adults, 50-100 mg po daily hs; Children 1 mo and older, 1 mg/kg/d po
Off-Label Uses. None
MOA. Nitrofurantoin is a synthetic nitrofuran that inactivates bacterial ribosomes and is active against most bacteria that cause UTIs except Pseudomonas aeruginosa, Proteus sp., many Enterobacter sp., and Klebsiella spp. The drug is used primarily to prevent recurrent UTIs but is also effective in the treatment of uncomplicated UTIs.
Drug Characteristics: Nitrofurantoin
Medication Safety Issues: Nitrofurantoin
Drug Interactions: Nitrofurantoin
Adverse Reactions: Nitrofurantoin
Efficacy Monitoring Parameters. Resolution of clinical signs of infection within 2-3 d.
Toxicity Monitoring Parameters. Severe diarrhea, yellowing of skin or eye, unusual bruising or bleeding, blistering skin rash, or shortness of breath.
Key Patient Counseling Points. May make urine brown, this is not harmful, it is a breakdown product of the drug. Complete full course of therapy. For the suspension, shake well and store in the refrigerator, and note short expiration after reconstitution. Avoid mixing suspension with food or beverages, but food can be taken afterward. Symptoms should improve within 2-3 d; if they worsen, seek follow-up care.
Clinical Pearls. Nitrofurantoin does not reach effective levels in tissue and is only indicated for urinary tract infections (not pyelonephritis). May resume normal activities after 24 h of antibiotics if afebrile.