The Pharmacogenetic Study , Readiness to Change, and Pharmacological Intervention for Smoking Cessation in Schizophrenia
Status:
Completed
Trial end date:
2008-12-01
Target enrollment:
Participant gender:
Summary
Cigarette smoking represents a major health problem for patients suffering from
schizophrenia. Compared to the general population, schizophrenic patients are significantly
more likely to be addicted to nicotine. They also are more likely to be heavy smokers, and
tend to be exposed disproportionately to nicotine and other harmful ingredients in the
cigarette because of the observed tendency to smoke down to the very end. Further, smoking in
these patients may be associated with a higher risk for developing tardive dyskinesia All of
these factors render schizophrenic patients a particularly vulnerable group for the
detrimental effects of tobacco-related medical problems. Currently, there is little
information available regarding the efficacy and utility of smoking cessation treatment
methods, as well as factors that may predict patients' response to such treatments.
An important related issue is the influence of smoking, and its cessation, on the effects of
the medications most of these patients rely upon for the control of their psychiatric
symptoms. Although smoking has long been known to significantly alter the metabolism, and
thus the effects, of most antipsychotics, the extent and clinical significance of these
influences have rarely been assessed. It is unclear to what extent smoke cessation (as well
as initiation) changes the side effect profiles of these medications, and whether such
changes contribute towards the difficulties in patients' ability and/or willingness to stop
smoking.
In addition, except pharmacological intervention, readiness to change may be an important
factor affecting the outcomes of smoking reduction. Prochaska et al proposed the concept of
stages of change to predict the response of quitting behavior for substance use. A lot of
evidence support the stronger of readiness of change, the higher successful rate of quitting
can be reached. Yet these results are largely found in many non-pharmacological intervention
and smoking cessation programs for general population. Till now, no available study solely
focus readiness of change quitting smoking behavior in NRT treatment for chronic
schizophrenic patients. Thus, we have an a great interest in examining the association
between the stages of change and the outcomes of smoking-cessation along with reduction among
schizophrenic patients receiving transdermal nicotine patches.
In order to begin addressing these important issues, this application proposes to utilize
state-of-the-art methodologies derived from the field of pharmacogenetics, molecular biology
and clinical trials, to (1) examine short-term and long-term efficacy of standard treatment
methods, such as the use of nicotine patches, in this population; (2) identify factors that
might predict treatment responses; and, (3) examine the interactions between smoking and the
effect of antipsychotics, as well as how such interactions might affect smoking cessation.
(4) to examine the predictive value of the stages of change on smoking cessation and
reduction outcomes in schizophrenic patients receiving different doses of nicotine
replacement therapy (NRT) and bupropion as implemented in a randomized trial.
Phase:
Phase 4
Details
Lead Sponsor:
Yu-Li Hospital
Collaborators:
Department of Health, Executive Yuan, R.O.C. (Taiwan) National Health Research Institutes, Taiwan