Autonomic Nervous Systems
Drug not given in acute angle glaucoma
a. Fluphenazine is a piperazine derivative of phenothiazine type. The drug has anticholinergic property. Therefore, it has the potential to cause worsening of narrow angle glaucomA.
b. Once released in the blood, fluphenazine decanoate is rapidly hydrolyzed by blood esterases with no attenuation of its antipsychotic action.
c. The onset of action generally appears between 24 to 72 hours after injection, and the effects of the drug on psychotic symptoms become significant within 48 to 96 hours. Amelioration of symptoms then continues for 1 to 8 weeks with an average duration of 3 to 4 weeks.
d. There is considerable variation in the individual response of patients to this depot fluphenazine and its use for maintenance therapy requires careful supervision.
e. Like other phenothiazines fluphenazine exerts activity at various levels of the CNS as well as on peripheral organ systems which accounts for its antipsychotic action and side effects.
f. Indirect evidence indicates that the antipsychotic effects of phenothiazines are linked to their effect in blocking dopamine and other catecholamine receptor sites.
g. Fluphenazine differs from some phenothiazine derivatives in several respects: It has less potentiating effect on CNS depressants and anesthetics than do some of the phenothiazines and appears to be less sedating.
h. While hypotension may occur less frequently than with other phenothiazines, appropriate precautions should be observed when using fluphenazine decanoate (see Precautions). Fluphenazine however, is among the group of phenothiazines which exhibit a greater propensity for producing extrapyramidal reactions (BG Katzung’ 10th Edition, pp-461).