Anticholinergic antiparkinsonian therapy in outpatients treated with neuroleptic drugs: a prescription survey

A review of pharmacoepidemiologic studies of antipsychotic use in children and adolescents

OBJECTIVE

In Canada, treatment of children and adolescents with antipsychotics is almost always off label. A single atypical agent, aripiprazole, only recently received regulatory authorization for use in the group aged 15 to 17 years. This regulatory approval was restricted to treatment of schizophrenia. The objective of this review was to summarize pharmacoepidemiologic reports examining the frequency of use of these medications.

METHODS

A literature search was used to identify English-language studies examining the pharmacoepidemiology of antipsychotics in children and adolescents. The results of identified studies were summarized using narrative review methods.

RESULTS

In countries where longitudinal data are available, increased antipsychotic use has been consistently observed. Generally, most or all of this increase can be attributed to second-generation antipsychotics (SGAs). Major international differences are evident in the literature. European studies describe lower overall frequencies of use than North American studies (most of which were conducted in the United States). SGAs in children and adolescents are used more often in boys than in girls, and are increasingly used for treatment of attention-deficit hyperactivity disorder (ADHD) and conduct disorder (CD).

CONCLUSIONS

Determining the most appropriate frequency of SGA use in children and adolescents will ultimately depend on decisive clarification of risks and benefits. The currently available literature highlights large international differences in the frequency of use. These differences may reflect fundamental dissimilarities in the therapeutic stance adopted toward ADHD and CD by physicians practicing in different countries.

A comparative study of the plasma membrane permeabilization and fluidization induced by antipsychotic drugs in the rat brain

We compared the potency of the interaction of three antipsychotic drugs, i.e. chlorpromazine (CPZ), haloperidol (Hal) and sulpiride (Sul), with the plasma membrane in the rat brain. CPZ loading (> or = 100 microM) dose-dependently increased both membrane permeability (assessed as [18F]2-fluoro-2-deoxy-D-glucose-6-phosphate release from brain slices) and membrane fluidity (assessed as the reduction in the plasma membrane anisotropy of 1,6-diphenyl-1,3,5-hexatriene). On the other hand, a higher concentration of Hal (1 mM) was required to observe these effects. However, Sul failed to change membrane permeability and fluidity even at a high concentration (1 mM). These results indicated the following ranking of the potency to interact with the membrane: CPZ>Hal>Sul. The difference among antipsychotic drugs in the potency to interact with the plasma membrane as revealed in the present study may be partly responsible for the difference among the drugs in the probability of inducing extrapyramidal side-effects such as parkinsonism and tardive dyskinesia.