Adverse drug reactions due to atypical antipsychotics in the absence of other centrally acting drugs among patients with mental illness

Background: Atypical antipsychotics are known as the second-generation antipsychotics, which act through various receptors and are preferred over typical antipsychotics as they have a better safety profile. Adverse Drug Reactions (ADRs) of atypical antipsychotics have a negative impact on long-term compliance and in achieving specified treatment outcomes. The present study aimed to monitor and report the ADRs of atypical antipsychotics in a population that was free from typical antipsychotics, antidepressants, and antianxiety drugs. Method: It is a hospital-based prospective observational study conducted in inpatients and outpatients of the Dept. of Psychiatry. Naranjo's Causality Assessment Scale, WHO Probability Assessment Scale, and Hartwig's Severity Assessment Scale were used for ADR assessment and categorization. The data were analyzed using MS Office Excel 2016. Results: The study was carried out among 49 patients with a number of antipsychotics per prescription that were observed to be 1.2± 0.4. A total of 63 ADRs were reported in the study population among which olanzapine (44%) was found to be contributed to the maximum number of ADRs followed by risperidone (37%). Weight gain (13%) was the most common ADR found in the study population followed by sedation (10%) and constipation (8%). The reactions were assessed for preventability and predictability and it was noted that 67% and 76% were probably preventable and predictable.  Conclusion: The study advocates for an important aspect of drug safety and improved monitoring among first-episode schizophrenia patients as most of the ADRs reported were predictable and preventable.