Effect of dose size on amodiaquine pharmacokinetics after oral administration

Plasma and urine concentrations of amodiaquine (AQ) and desethylamodiaquine (AQm) have been measured after oral administration of AQ 200, 400 and 600 mg in randomised order to 6 healthy subjects. The relationships between AQ dose size and the areas under the plasma concentration vs time curves for AQ and AQm were linear. Likewise there were linear relationships between AQ dose size and the mass of both AQ and AQm excreted in the urine. These data indicate that after oral administration within this dose range AQ displays first-order pharmacokinetics.