Do enzyme inducers modify haloperidol decanoate rate of release?
1. Plasma levels were monitored for about 18 months during therapy with haloperidol decanoate. When steady-state was reached, patients treated without enzyme inducers showed in their plasma concentrations a stable plateau and a very low fluctuation. Furthermore, doses were correlated to plasma levels (r = 0.9). 2. Contrary, patients treated with both haloperidol decanoate and enzyme inducers seemed to present in their plasma concentration a very large fluctuation with C min (plasma concentrations measured just before the injection) significantly lower than those of the other group. Moreover their C min values were excluded from the linear regression curve calculated between plasma levels and doses in patients without enzyme inducers. 3. Our data suggest a shortening of the absorption half-time of haloperidol. In this case, it seems necessary to diminish the interval between injections than to give higher dosage in order to maintain plasma concentrations.
Pupeschi
G
G
Montperrin Hospital, Aix-en-Provence, France.
Agenet
C
C
Levron
J C
JC
Barges-Bertocchio
M H
MH
D014150:Antipsychotic Agents / Q000097:blood* / Q000493:pharmacokinetics / Q000627:therapeutic use; D002220:Carbamazepine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006220:Haloperidol / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D006801:Humans; D010634:Phenobarbital / Q000494:pharmacology*; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy*
D014150:Antipsychotic Agents; D002220:Carbamazepine; C033563:haloperidol decanoate; D006220:Haloperidol; D010634:Phenobarbital