Determination of Adherence in Patients Admitted to a Psychiatric Unit for Decompensated Psychosis: an Analysis of Serum Levels of Antipsychotics.

We hypothesize that a majority of patients admitted to an inpatient psychiatric service for an acute exacerbation of schizophrenia, schizoaffective disorder, or bipolar I disorder will have plasma levels of antipsychotic below the lower threshold of the accepted therapeutic range as determined by the Arbeitsgemeinschaft fur Neuropsychopharmakologie und Pharmakopsychiatrie (AGNP). We aim to estimate the frequency of total and partial non-compliance with antipsychotics in adults with schizophrenia, schizoaffective disorder, or bipolar I disorder who are admitted to an inpatient psychiatric service with psychosis. In order to do so, we will measure serum levels of five commonly prescribed antipsychotics (risperidone, olanzapine, quetiapine, paliperidone and aripiprazole) drawn in the emergency room setting to establish the degree of compliance in admitted patients. On admission to the inpatient psychiatry service, blood is routinely drawn on all patients via single venipuncture for review of basic laboratory values; 2 tubes are typically drawn. Investigators will collect a third tube (approximately 2-3 mLs) on all patients prescribed one of the above medications who are admitted with a psychotic decompensation. This will continue until 100 patients are enrolled. The extra blood will be sent for determination of serum level of the drug in question. Each subject will be assigned a unique identification number generated by the principle investigator, and data will be coded using this number. The following data: age, gender, ethnicity, body mass index, specific diagnosis, and prescribed dosage of the drug in question will be obtained from the subject's medical records. We will then use the AGNP expert group consensus guidelines for therapeutic drug monitoring to determine the degree of compliance in the specific patient. All data will be obtained from information available to the clinician (demographic data and previous dosing) or obtained from the small additional blood sample. Samples will not be stored for future use; residual samples will be destroyed. For the purposes of this exploratory pilot study we are primarily interested in determining the proportion of patients receiving any of five antipsychotic drugs who have blood levels below an expected therapeutic range. 100 subjects will permit an initial estimate with reasonable confidence intervals. We will also carry out exploratory analyses to examine the relationship between lower than expected blood levels and diagnostic and demographic patient characteristics. This will help to inform future research projects and clinical initiatives.