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This study proposes to investigate the efficacy of varied-dose transdermal nicotine patches for the purpose of inducing smoking cessation among 240 motivated adult psychiatric outpatients with schizophrenia, who are otherwise healthy, and receiving antipsychotic therapy. Additionally, the study will examine the possible genetic factors associated with predicting treatment response, the effects of smoking cessation on the metabolism of antipsychotics, and how these effects might influence smoking cessation.
After obtaining informed consent from the qualifying study candidates, a screening will be conducted including a physical examination, blood and urine tests, as well as a psychiatric history, and a variety of psychological assessments and questionnaires. Only healthy candidates meeting inclusion criteria will be accepted into the active study beginning the following week (Week 0) for treatment randomization.
Volunteers will be randomized into one of two treatment groups: (a) usual dose and (b) high dose patches. Treatments will be divided into 4 steps, with Step 1 lasting six weeks, and Steps 2-4 lasting two weeks each. Both groups will receive two identical patches during Steps 1-3, and then tapering to one patch in Step 4. Active nicotine patch treatment will be tapered at each new step. In addition, a psychoeducational program based on the US Public Health Service Clinical Practice Guideline for Treating Tobacco Use and Dependence will be offered to each of the subjects.
Once accepted into the study, the subjects will be seen weekly for the first 12 weeks, and the last follow-up visit at Week 24. During each of these visits, the subjects will be tested for carbon monoxide level in their breath, and saliva samples will be obtained for the measurement of cotinine, the major metabolite of nicotine. Blood samples will be obtained during three of these visits for the measurement of the antipsychotic levels. A one-time DNA blood sample will be taken at Week 0 to establish the genotype (for the detection of variant alleles that may predict the success of smoking cessation). Assessments and questionnaires will be repeated at various intervals throughout the study.
At Weeks 0, 8, and 24, the subjects will be given a 100 mg tablet of caffeine to take orally before collecting an 8-hour urine sample. This will be used to measure how quickly the individual metabolizes caffeine in order to establish their CYP1A2 activity. This is about the same amount of caffeine found in a cup of coffee, so adverse effects are not expected.
In summary, this is a potentially beneficial study for smoking individuals with schizophrenia who are motivated to quit smoking with the use of nicotine patch and psychoeducational therapies. The adverse effects associated with nicotine patches are similar to those related to regular cigarette use (e.g., increased heart rate, palpitations, increased blood pressure) with the addition of skin rash, swelling, or irritation due to the use of adhesive patches. All potential adverse effects will be assessed at every clinic visit. The risks associated with this study include the potential for nicotine overdose, exhibited by symptoms such as nausea, vomiting, dizziness, and weakness. Subjects will be informed of these potential effects and instructed to contact the P.I. should serious symptoms occur. There is some discomfort but minimal risk in collecting blood samples from a vein in their arm, such as bruising, mild pain, and in rare cases, infection, but this is not expected. |
