Heart Rate Changes in Schizophrenic and Bipolar Patients Under the Medication of Aripiprazole and Quetiapine

Primary Goal: The goal of this research is investigating the heart rate changes in schizophrenic and bipolar patients under the medication of aripiprazole and quetiapine. As we known, clozapine, an antipsychotic, could cause fatal cardiac arrhythmia; in previous reports showed fatal rate about 0.7%, in spite of not very high, it reflects heart rate change decreasing. Therefore, many researches begin to focus on the relationship and heart rate change. Quetiapine, an atypical antipsychotic, FDA approved in 1997, Department of Health (DOH) in Taiwan also approved for schizophrenia for its effectiveness of negative disorders, low extrapyramidal syndrome, low side-effects of muscle catatonia and sluggishness. The side-effects of quetiapine are lethargy, nausea (occur rate 9%-44%), insomnia (12%), postural hypotension (4%-7%), constipation(8-10%), thirsty (9%-44%), weight gain (5-23%) and liver enzyme (GGT、AST、ALT) increasing (6%). Aripiprazole, FDA approved in 2002, DOH in Taiwan also approved for schizophrenia for its effective remittance of positive disorders, also effective for negative disorders and cognitive function regression. Besides, aripiprazole combine lithium or valproic acid can control the onset of manic and mixure of bipolar patients. The side-effects of aripiprazole are few, low extrapyramidal syndrome, no significant weight gain and blood sugar level, not surge in prolactin level and low menstrual cycle abnormal, gynecomastia and sexual dysfunction. Other side-effects are postural hypotension (0.6%-4%), headache (12%-27%), lethargy (8%-18%), insomnia (5%-26.3%), constipation (5-11%). Both quetiapine and aripiprazole are atypical antipsychotic, serious side-effects are fewer than typical antipsychotics, however, in some sensitive patients still have some side-effects such as limb-stiffness and akathisia (quetiapine 4%-12%, aripiprazole 2%-27.3%). In some retrospect researches, quetiapine will increase the opportunity of cardio- sudden death and pass off by 0.3%-1% in age 30-74 adult. On the other hand, aripiprazole (0.1%-1%) showed prolonging of QT wave which was considered as a danger factor of fatal arrhythmia. Despite of the danger, serious side-effects are rare, aripiprazole and quetiapine are widely used in clinical.

This study hope to further study whether quetiapine and aripiprazole will occur heart rate changes similar to clozapine, using heart rate changes approach to find out the possibility of causing arrhythmia and fatal of these 2 medicines.

Secondary goal:

1. Further investigate the relationship of drug dosage and heart rate change, in order to acquire the best relationship both effectiveness as well as safety in acceptable heart rate change of clinical suggestion.
2. The subjects of this study are schizophrenic and bipolar patients, who use quetiapine and aripiprazole, also will stratify into gender, age and influence of heart rate changes.