Safety and cardiovascular effects of multiple-dose administration of aripiprazole and olanzapine in a randomised clinical trial

Abstract

Objective: To assess adverse events and safety of aripiprazole and olanzapine treatment. Methods: Twenty-four healthy volunteers receiving 5 daily oral doses of 10 mg aripiprazole and 5 mg olanzapine in a crossover clinical trial were genotyped for 46 polymorphisms in 14 genes by qPCR. Drug plasma concentrations were measured by HPLC-MS/MS. Blood pressure and 12-lead ECG were measured in supine position. Adverse events were also recorded. Results: Aripiprazole decreased diastolic blood pressure on the first day and decreased QTc on the third and fifth day. Olanzapine had a systolic and diastolic blood pressure, heart rate and QTc lowering effect on the first day. Polymorphisms in ADRA2A, COMT, DRD3 and HTR2A genes were significantly associated to these changes. The most frequent adverse drug reactions to aripiprazole were somnolence, headache, insomnia, dizziness, restlessness, palpitations, akathisia and nausea while were somnolence, dizziness, asthenia, constipation, dry mouth, headache and nausea to olanzapine. Additionally, HTR2A, HTR2C, DRD2, DRD3, OPRM1, UGT1A1 and CYP1A2 polymorphisms had a role in the development of adverse drug reactions. Conclusions: Olanzapine induced more cardiovascular changes; however, more adverse drug reactions were registered to aripiprazole. In addition, some polymorphisms may explain the difference in the incidence of these effects among subjects.