Variability of urinary dapsone/creatinine concentration ratios in leprosy patients fully compliant with dapsone therapy

Abstract

A highly sensitive and reproducible assay procedure for the determination of dapsone (DDS) and hydrolizable metabolites in urine is described. DDS/creatinine (D/C) concentration ratios, which are used to monitor compliance with DDS therapy, have been determined on samples of all urine voided throughout a 24-h period by 7 leprosy in-patients fully compliant with their therapy. The D/C concentration ratios varied both within and between patients over the 24 h and the time-course of variation showed no closely predictable pattern. Urinary excretion of DDS over the 24 h was found to be 74.8% ± 5.7 % (S.E.M) uncorrected or 90.2% ± 6.8% corrected for recovery. Our results indicate an unreliability in the use of single urine samples to determine D/C ratios and hence compliance by individual patients with their DDS therapy.