Adverse Reactions to Nitrofurantoin

Introduction to Adverse Reactions

Medication cessation should be undertaken if the risk-benefit analysis favors discontinuation, especially in cases of severe skin reactions or hypersensitivity reactions to nitrofurantoin, as recommended by the British Association of Dermatologists guidelines 1

For patients experiencing itching while taking nitrofurantoin, the application of moderate to high-potency topical corticosteroids to affected areas and the use of moisturizing lotions for dry skin may be recommended, along with non-sedating antihistamines (such as loratadine 10 mg daily) for daytime use and sedating antihistamines (like diphenhydramine 25-50 mg or hydroxyzine 25-50 mg) at night if sleep is affected 2
If symptoms worsen or do not improve after 48-72 hours of symptomatic treatment, nitrofurantoin should be stopped immediately, and alternative antibiotic therapy will likely be needed to treat the underlying urinary tract infection, as recommended by the British Association of Dermatologists guidelines 1

The severity of itching should be evaluated as mild, moderate, or severe, considering accompanying symptoms such as rash, hives, respiratory symptoms, fever, or chills, and the timing of symptom onset (whether within the first week or after prolonged use) to determine if the reaction is acute or chronic 2

Patients should seek immediate medical attention if they experience difficulty breathing, swelling of the face, lips, tongue, or throat, severe skin reactions, high fever, or severe dizziness, and it is essential to document any significant reactions to nitrofurantoin in medical records to avoid future exposure, as recommended by the British Association of Dermatologists guidelines 1
The American College of Physicians recommends evaluating the severity of pruritus based on the extent of body surface area affected and its impact on daily activities, considering the patient's history of previous antibiotic reactions, and considering treatment intensification with oral prednisona (0.5-1 mg/kg/day), antihistamines, and gabapentinoids (such as gabapentina 900-3600 mg/day or pregabalina 25-150 mg/day) if necessary 2, 1
The patient should be reevaluated after 48-72 hours, and if there is improvement, the symptomatic treatment should be continued, but if the condition worsens or new symptoms appear, consideration should be given to suspending the antibiotics and seeking alternative therapeutic options, as recommended by the American College of Physicians and the British Association of Dermatologists guidelines 2, 1