Abstract
Background: Clozapine levels are severely decreased by cigarette smoke hydrocarbons. A new agent that is unaffected by smoking is paliperidone palmitate. Objective: The purpose of this study is to retrospectively evaluate hospital readmission and time until readmission for patients prescribed paliperidone palmitate intramuscular injection (PP) as an alternative to oral clozapine for patients with severe schizophrenia who resume smoking following discharge. A secondary analysis was performed to determine whether smoking status alone affects hospital readmission rates in both smoking and nonsmoking clozapine-treated patients. Methods: This was a retrospective analysis of all patients who were positive for smoking at admission and readmission who were prescribed clozapine and PP. Smokers were identified by concurrent orders for nicotine replacement. Readmission rates and time until readmission were determined. Data were analyzed utilizing nonparametric statistical methods. Results: A total of 133 subjects were identified, including 108 smokers in PP group, 18 smokers in clozapine group, and 7 nonsmoking clozapine patients. Readmission rates were statistically significant between smokers in the clozapine and PP groups, with significantly lower readmission rates in the PP group (p = .004). In the sub-analysis, hospital readmissions between smokers and nonsmokers in the clozapine group were statistically significant (p = .027). Results may be influenced by use of a single hospital site, limits of a retrospective analysis, and variation in pharmaceutical preparation. Conclusion: PP may be a reasonable alternative to clozapine in severe schizophrenia for patients who continually resume smoking following discharge. Smoking may also be an important predictor of decompensation in smokers prescribed clozapine. A further prospective study is warranted.