Comparative Trial of Two Sulfisoxazole Regimens in Acute Urinary Tract Infection

Abstract

Traditionally, the therapeutic regimen of sulfisoxazole in acute urinary tract infection has included either a 2- or 4-g loading dose. However, the biopharmaceutical aspects of this drug indicate that a loading dose is unnecessary. The objective of this clinical study, therefore, was to compare a traditional regimen of sulfisoxazole to a regimen not utilizing a loading dose. Fifty adult female patients with acute, uncomplicated urinary tract infections were assigned to a ten-day course of sulfisoxazole 1 g po qid. Patients were randomly allocated to a 2-g loading dose or no loading dose regimen. Data were analyzed with regard to resolution of presenting symptoms and eradication of the infecting organism (i.e., cure). Statistical analysis demonstrated no significant difference for symptom resolution and cure. It appears that the convention of using an initial 2-g oral loading dose of sulfisoxazole in the treatment of acute, uncomplicated urinary tract infection is unwarranted.