Abstract
Interactions between acetyl salicylic acid (ASA) and acetaminophen (AC) with domperidone were investigated by oral administration of ASA (50 mg/kg) or AC (100 mg/kg) alone or in combination with domperidone (1 mg/kg) to rabbits. Plasma samples were collected before and 5, 10, 15, 20, 25, 30 and 45 min and 1, 2, 3, 4, 6, 10, 24 and 30 h after ASA administration. Similarly, plasma samples were collected before and 0.25, 0.5, 0.75, 1.25, 2, 3, 4.5 and 6.0 h after AC administration. Assays of ASA and AC in plasma were performed using HPLC methods. Domperidone had no significant effect on the maximum plasma concentration (C
max), the time taken to reach C
max (T
max), the area under the curve (AUC) to infinity and the elimination half-life (
t
1
2
) of ASA and AC. However, domperidone significantly increased the plasma AC concentrations at 1.25 and 2.0 h in comparison with the control. Also. domperidone consistently demonstrated an increase in AUCs up to 6 h and to infinity for AC after domperidone administration in all of 5 rabbits. It was concluded that domperidone (1 mg/kg) does not significantly affect ASA and AC absorption in rabbits.