Blood and plasma kinetics of cis(Z)-clopenthixol and fluphenazine in psychiatric patients after intramuscular injection of their decanoic esters.

Whole blood and plasma concentrations of active neuroleptic drugs were measured in eight schizophrenic outpatients who had received cis(Z)-clopenthixol decanoate in Viscoleo or fluphenazine decanoate in sesame oil by intramuscular injection. Whole blood and plasma concentrations were very similar, though there was a slight tendency for blood concentrations to be higher than plasma concentrations. Maximum concentrations appeared at 1 week after administration of cis(Z)-clopenthixol decanoate, whereas the highest concentrations after fluphenazine decanoate were seen at the end of the 3-week dosage interval. Some between-individual variation and a limited within-individual variation was seen.