Disposition of quinine in plasma, red blood cells and saliva after oral and intravenous administration to healthy adult Africans.

The pharmacokinetics of quinine has been studied in ten healthy adult Africans after intravenous infusion and oral ingestion of a 500 mg dose. Blood and saliva samples were collected over 48 h and quinine in plasma, red cells and saliva was determined by HPLC. Quinine was rapidly and almost completely absorbed after an oral dose, with absorption half-life of 0.53 h, a tmax of 1-3 h and a bioavailability of 88%. Analysis of the i.v. data gave an apparent volume of distribution of 3.6 l.kg-1 and a plasma clearance of 0.19 l.kg-1.h-1. The concentration-time curves for plasma, red cells and saliva had declining phases were approximately parallel, giving a similar half-life that in all three media. The half-lives after the i.v. infusion also did not different from those after oral administration. The dose was well tolerated by both methods of administration.