Abstract
Background: Adverse drug reactions from the use of sulfadoxine-pyremathamine (fansidar) as chemoprophylaxis and in uncomplicated malaria have been well reported. However, this occurrence differs from patient to patient and not always predictable with fatal consequences. These adverse events result from long duration of action and patients not observing the predefined interval and washout periods. The aim of this study was to assess the influence of a single dose activated charcoal on the body burden of sulfadoxine in male healthy volunteers. Materials and Methods: The study was crossover design carried out in 2 phases comprising of initial administration with sulfadoxine-pyremathamine alone. After 30 days washout, same subjects were given fansidar with a single dose activated charcoal. Urine samples were collected over 60 h period. Using Bratton-Marshall method modified by Almeida-Filho and Souza, amount of sulfadoxine was determined and body burden was calculated using Kinetica 5 software. Results: The study revealed reduced rates of excretion at 18 and 30 h for sulfadoxine alone and sulfadoxine plus activated charcoal respectively. The average amount in the urine was also reduced from 43-21% when activated charcoal was added and total body burden reduced as well. Also, activated charcoal did not influence kel, t(1/2) and t(max) of sulfadoxine, but affected its C-max and AUC((tot)) which were significantly reduced. Conclusions: Therefore, single dose activated charcoal effectively decreased the body burden by reducing the absorption of sulfadoxine. This suggests that timely use of activated charcoal will mitigate the effects of long acting sulfadoxine by reducing the body burden in cases of inadvertent overuse.