New Haven, Conn. – Schizophrenics who took the newer anti-psychotic drugs along with the nicotine patch had nearly triple the success rate quitting smoking as schizophrenics taking more traditional anti-psychotic medications and the nicotine patch, a Yale study shows.
As many as 90 percent of schizophrenic patients smoke. Researchers have found that smoking may enhance cognitive function and reduce movement disorder symptoms in schizophrenics, which they speculate may explain the high prevalence of smoking in that population. The newer, or "atypical," antipsychotic medications can enhance certain cognitive functions and are associated with less motor side effects.
"This confirms that the newer medications used to treat schizophrenia also might be helpful for these patients in treating smoking and other types of drug dependencies," said Tony George, M.D., assistant professor of psychiatry at Yale School of Medicine and lead author of the study in the American Journal of Psychiatry. "And because so many schizophrenics smoke, this finding could have substantial public health implications. Rates of certain diseases, particularly cardiovascular disease, are much higher among schizophrenics."
The study also found that the nicotine patch, which usually yields a 50 to 60 percent end of treatment success rate in smokers who do not have mental illness, was not particularly effective by itself with schizophrenics. In addition, the researchers found that a specialized group therapy program for schizophrenic patients for quitting smoking was no more helpful to subjects with schizophrenia than the smoking cessation program offered by the American Lung Association.
More traditional types of medication for schizophrenics such as Haldol and Thorazine have multiple side effects like muscle stiffness and abnormal movement of the face and extremities because they block the subclass of dopamine D2 receptors in regions of the brain that control movement.
The new class of medications for schizophrenics, the "atypical" antipsychotics, which include Risperidone (Risperdal) and olanzapine (Zyprexa), probably are effective for schizophrenia because they block receptors other than those for dopamine, and block the dopamine receptors in motor pathways to a lesser extent than the traditional "typical" antipsychotic medications.
"Because these newer drugs work so well, these drugs have given researchers new insights into the pathophysiology of schizophrenia," George said.
He said the more traditional drugs are still prescribed for about half of schizophrenic patients for a variety of reasons. In some cases the patients do not respond to the newer drugs. The newer medications also are more expensive and are not as yet available in long-acting, injectable form. A major problem with schizophrenics is that many do not consistently take their antipsychotic medication.
"If schizophrenic patients are smoking to alleviate some of the side effects of medications, maybe switching to the newer medications could help reduce their nicotine addiction," George said.
The study involved 45 tobacco-dependent patients diagnosed with schizophrenia and who smoked about a pack of cigarettes a day. The patients were assigned either to the American Lung Association program for smokers or the specialized group for schizophrenic smokers. Each group received the therapy for 10 weeks. All of the subjects were given the nicotine transdermal patch, which helps alleviate withdrawal and craving symptoms for people quitting smoking by delivering small amounts of nicotine into the bloodstream.
The investigators found significant differences on smoking cessation rates between patients who took traditional anti-psychotic drugs and non-traditional anti-psychotic drugs. At the end of a 12-week trial, 10 of 18 subjects, or 56 percent, who were taking the more modern drugs were still not smoking. Only six of 27 subjects, or 22.2 percent, taking the more traditional drugs had maintained abstinence from nicotine.
"Besides having the quit rates substantially elevated, we actually did an objective measure of smoking, checking carbon monoxide levels (a by-product of cigarette smoke), Schizophrenics and Smoking)and found a substantial reduction in carbon monoxide levels in patients who were prescribed the newer medications," George said. "People on the more traditional medications actually increased their rate of smoking."
The other researchers on the study were Bruce Rounsaville, M.D., professor of psychiatry; Thomas Kosten, M.D., professor of psychiatry; Douglas Ziedonis, M.D., associate professor of psychiatry at Robert Wood Johnson Medical School in New Jersey; Alan Feingold, associate research scientist in psychiatry, and research assistants W. Thomas Pepper, Cheryl Satterburg, and Justin Winkel.
Materials provided by Yale University. Note: Content may be edited for style and length.
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