Pharmacotherapy prescribing patterns in the treatment of bipolar disorder in an outpatient population at Tara hospital
Date
2015
Authors
Holzapfel, Eleanor
Journal Title
Journal ISSN
Volume Title
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Abstract
Introduction
Pharmacotherapy is a key component in the management of bipolar disorder. Whilst one might
aim for fewer agents, not all patients with bipolar disorder can be stabilized with monotherapy and
combination treatment (polypharmacy) is increasingly used to manage patients in clinical practice.
Mood stabilizers have traditionally been prescribed as monotherapy, however the use of atypical
antipsychotic agents is seen in clinical practice with various such agents approved for such usage.
Combination treatment with an antipsychotic, preferably an atypical antipsychotic together with a
standard mood stabilizer is also noted in clinical practice as well as recommended by guidelines.
Bipolar patients managed in a specialist psychiatric setting have a greater chance of being
managed with polypharmacy than in a general practice setting. The use of polypharmacy may
also be attributed to receiving treatment in an academic environment.
This current study was based on the application of diagnostic criteria and principles of the
Diagnostic and Statistical Manual of Mental Disorders version IV TR (DSM IV TR), published by
the American Psychiatric Association and The International Classification of Diseases version 10
(ICD 10), published by the World Health Organisation.
Aims
The study aims to describe the range and frequency of medications used in the management of
bipolar bisorder in a specific setting as well as describe the nature and frequency of monotherapy
versus polypharmacy use.
Hypothesis
The study hypothesized that the majority of patients attending the specialist / academic psychiatric
outpatient clinic at Tara Hospital would be prescribed polypharmacy and that antipsychotics
(typical or atypical) would be prescribed in combination with standard mood stabilizers in the
majority of cases.
Method
The study took the form of a retrospective patient file review. The clinical files were for patients
attending the Tara Hospital psychiatric outpatient clinic. The files of every patient who attended
the clinic at least once in 2009 were screened and included in the study where the recorded ICD
10 code corresponded with a bipolar disorder subtype or a single manic or hypomanic episode.
Where the recording of the ICD 10 code was missing or incomplete further scrutiny of the clinical
notes enabled the researcher to establish a diagnosis of bipolar disorder using the ICD 10 and/ or
DSM IV TR diagnostic criteria and therefore include the patient file in the study. Other necessary
information was obtained by reviewing clinical notes as well as the prescription written on the last
patient visit for 2009.
Results
The study found that the majority of patients (93.8%) were prescribed polypharmacy, with 3.2 the
mean number of psychotropic medications prescribed per patient. Lithium was prescribed in
34.3% of patients. Sodium valproate was prescribed in 37.1% of patients. Eighty three point eight
percent (83.8%) of the patients were prescribed at least one standard mood stabilizer. The
atypical antipsychotics (46.6%) were prescribed more frequently than the typical antipsychotics
(16.5%). Lamotrigine (31.8%) was the preferred novel anticonvulsant and the selective serotonin
reuptake inhibitors (SSRI’s) were the most commonly prescribed antidepressant (28.9%).
Clonazepam (26.8%) was the most frequently prescribed benzodiazepine add-on. The use of
combination treatment to manage bipolar disorder was the rule rather than the exception. There
was however much variety in the combinations used with no particular combination being
prescribed in the majority of patients. Forty seven percent (47%) of the combinations used
included a standard mood stabilizer and a typical or atypical antipsychotic.
Conclusion
The current study provides preliminary data on the prescribing patterns in bipolar disorder in a
specialist psychiatric clinic within an academic complex in South Africa. The findings are in
keeping with international studies and highlights that polypharmacy and combination treatment in
the management of bipolar disorder is the norm in such settings. There is a large variation in
clinician practices and much variety seen in the combinations of medications used to treat bipolar
disorder despite the availability and use of treatment guidelines. This is perhaps because bipolar
disorder is such a complex disorder and that most of the treatment recommendations are based
on limited data. Treatment guidelines have emerged in order to attempt to standardize treatment
and provide clinicians with algorithms to utilize and apply research findings in daily clinical
practice. Further study into the effective prescribing principles for bipolar disorder is necessary.
Description
A research report submitted to the Faculty of Medicine, University of the Witwatersrand Medical School, in partial fulfilment of the requirements for the Degree Masters of Medicine in the branch of Psychiatry, Johannesburg, August, 2015