A Prospective Study of Adverse Drug Reactions in Patients with Bipolar Disorder in Psychiatry Outpatient Department of a Tertiary Care Hospital

Abstract

Introduction: Bipolar disorder is a chronic, debilitating psychiatric disorder. Mood stabilizers and atypical antipsychotics are first line drugs for bipolar disorder. They have significant adverse effects.

Aim: The study was conducted with an aim to evaluate the pattern of occurrence of Adverse Drug Reactions (ADRs) in the patients with bipolar disorder and to assess their causality, severity and preventability.

Materials and methods: A prospective and observational study - carried out in the psychiatry outpatient department of New Civil Hospital, Surat for 15 months. All patients diagnosed with bipolar disorder and receiving pharmacotherapy were included. Udvalg for Kliniske Undersøgelser (UKU) side effect rating scale and Abnormal Involuntary Movement Scale (AIMS) were used for documenting ADRs and tardive dyskinesia, respectively. Assessment of causality, severity and preventability of recorded ADRs was done using Naranjo's algorithm and WHO-UMC scale, modified Hartwig and Seigel Scale and modified Schumock and Thornton scale, respectively. Descriptive statistics was used (percentage, mean±standard deviation) for presentation of demographics and other numerical data; Chi Square test and Fisher's exact test were used to assess association between variables. A p-value < 0.05 was considered significant.

Results: A total of 703 ADRs were recorded from 175 patients. The most common ADRs observed were asthenia (11.95%) and sedation (10.24%). Majority of ADRs were mild on assessment with UKU scale. Mood stabilizers (59.46%) were most frequently associated with ADRs and lithium was most common single drug responsible. Upon causality assessment, majority of the reactions were probable (54.77% with WHO-UMC scale, and 56.33% with Naranjo's algorithm). The association of results between the two scales was statistically significant (p<0.001). Majority of ADRs (70.27%) were assessed as mild and 64.30% of the ADRs were not preventable.

Conclusion: ADRs are a frequent occurrence in patients with bipolar disorder which are mild in most cases. Incidence of ADRs can be decreased and compliance as well as quality of life of patient can be improved by early detection and management.

Keywords: Antipsychotic agents; Causality assessment; Lithium; Pharmacovigilance; Valproate.

[Table/Fig-2]:

Pattern of adverse drug reactions. (n = 703).

[Table/Fig-3]:

Distribution of adverse drug reactions according to UKU scale. (n =604*). (* Acne, Anaemia, Abnormal involuntary movements, Alopecia, Anorexia, Oedema, Hypothyroidism and Slurring of speech were not included in this evaluation as they are not a part of standard UKU side effect rating scale.)

[Table/Fig-4]:

Degree of Adverse drug reactions according to UKU scale. (n = 604*). (*Acne, Anaemia, Abnormal involuntary movements, Alopecia, Anorexia, Oedema, Hypothyroidism and Slurring of speech were not included in this evaluation as they are not a part of standard UKU side effect rating scale.)

[Table/Fig-7]:

Causality assessment of ADRs using Naranjo’s algorithm and WHO-UMC scale. (n = 703).

[Table/Fig-8]:

Severity (Modified Hartwig and Seigel scale) and Preventability (Modified Schumock and Thornton scale) assessment (n = 703).