Oxamniquine pharmacokinetics in hepatosplenic schistosomiasis in the Sudan

Oxamniquine pharmacokinetics were determined in five normal Sudanese subjects and nine Sudanese patients with advanced hepatosplenic schistosomiasis, given 1 g as a single oral dose. There were no significant differences in oxamniquine mean area under the plasma concentration time curve (AUC), plasma half life (T1/2), or time to reach peak concentration (Tmax). However, patients had a 19% lower mean AUC, a 36% higher T1/2, and a 23% increase in Tmax. The peak concentration (Cmax) was 36% lower in patients (P = 0.04). There was no correlation between disease severity and oxamniquine pharmacokinetic values. A significant correlation between oxamniquine AUC and T1/2 suggests that its elimination may be non-linear. The higher dosage requirements for oxamniquine in the Sudan are unlikely to be due to lower plasma concentrations amongst the Sudanese.