Abstract

Nitrofurantoin is effective in the treatment of acute urinary tract infections, but its usefulness is limited by the high incidence of unwanted effects. When used in the recommended dose of 100 mg four times daily about a quarter of the patients may suffer nausea and vomiting.¹ A single dose of 100 mg at night for the prophylaxis of urinary infections² caused symptoms in 41% of patients.³ These unwanted effects seem to be related to peak plasma concentrations of the drug rather than to its action on the gut.