INFLUENCE OF ROUTE OF ADMINISTRATION ON HALOPERIDOL PLASMA-LEVELS IN PSYCHOTIC-PATIENTS

Abstract

Haloperidol plasma concentrations were determined in psychotic patients to whom the drug was given by 3 different routes of administration (i.v. perfusion, i.m. and orally). When measured 15 h after the last administration, a significant difference (P < 0.001) was found in the steady state plasma concentration between the oral and the i.m. route. The values were higher after i.m. administration and were subject to less interindividual fluctuation than after the oral. The reduction in plasma levels after oral administration in respect to i.m. were in accordance with the bioavailability of haloperidol. The opportunity of switching from oral to i.m. treatment is discussed.