[Haloperidol. Plasma monitoring and hormonal effects of treatment]

Therapeutic plasma monitoring of haloperidol, a major neuroleptic, measured by radioimmunoassay, has shown a rather good correlation between plasma level and dosage but with large interindividual variation in children as in adults; age seems not to have any effect on haloperidol metabolism. 80% of subjects present a concomitant prolactin levels variation, whereas in 20% no prolactin response is found. During acute kinetics of either a 10 mg oral haloperidol administration or a 250 mg intramuscular haloperidol decanoate injection, a parallel elevation of prolactin, cortisol, immunoreactive bêta-endorphin and bêta-lipotropin plasma levels occur, at the same time as haloperidol plasma levels. Those rise with a good equivalence between the two doses of the two forms.