The hidden magnitude of polypharmacy: using defined daily doses and maximum licensed daily doses to measure antipsychotic load

Antipsychotic polypharmacy and associated factors among patients with schizophrenia: Multicenter cross-sectional study in Northwest Ethiopia

BACKGROUND

Antipsychotic polypharmacy (APP) remains common despite guideline recommendations to minimize combinations, except after repeated antipsychotic monotherapy trials. This study aimed to assess APP and its associated factors among schizophrenia patients at comprehensive specialized hospitals in Northwest Ethiopia.

METHODS

An institutional-based cross-sectional study was conducted among 422 schizophrenia patients at selected hospitals in Ethiopia from June to August 2022. The data were collected using a semi-structured questionnaire. Study participants were enrolled using systematic random sampling. Data entry and analysis were done with Epi-data version 4.6.1 and SPSS version 24, respectively. APP was determined by reviewing the number of medications based on relevant evidence. A multivariable logistic regression model was fitted to identify APP factors. Variables with a p-value of < 0.05 at a 95% confidence interval were considered statistically significant.

RESULTS

From a total of 430 approached samples, 422 (98.1% response rate) eligible patients were included in the study. An overall APP prevalence was 22.7% (95% CI: 19-27). Duration of illness (AOR = 2.88; 95% CI: 1.49, 5.59); duration of treatment (AOR = 3.79; 95% CI: 1.05, 13.62); number of admissions (AOR = 4.93; 95% CI: 2.52, 9.64); and substance use (AOR = 2.58; 95% CI: 1.49, 4.47) were significantly associated with APP.

CONCLUSION AND RECOMMENDATION

In this study, APP was recorded in a considerable number of patients. Patients with a longer duration of illness and treatment, frequent admissions, and substance users need critical follow-up to minimize antipsychotic medication use.

Factors predicting high-dose and combined antipsychotic prescribing in New Zealand: High-dose antipsychotic prescribing

OBJECTIVE

Guidelines recommend using antipsychotic monotherapy at the lowest effective dose, however high-dose and antipsychotic polypharmacy prescribing (APP) remain commonplace. The aim of this study was to determine the prevalence and patterns of high-dose antipsychotic prescribing and APP among mental health service users in New Zealand (NZ).

METHODS

A retrospective audit of service users discharged from inpatient (n=657), or registered with community (n=1560), mental health services at Auckland District Health Board was undertaken. Case notes were reviewed and data on demographics, antipsychotic routes and doses were collected. Outcomes measures included: frequency of total high-dose prescribing, high-dose monotherapy, APP, high-dose APP, and factors associated with these prescribing practices. Logistic regression models were used to examine the relationships between explanatory and outcome variables.

RESULTS

Of the service users prescribed an antipsychotic (n = 2217), 14% were prescribed a high-dose antipsychotic. The frequency of high-dose monotherapy, APP, and high-dose APP was 3%, 26% and 11%, respectively. Being male, Māori, on compulsory treatment, having a schizophrenia diagnosis, or being prescribed polypharmacy were associated with high-dose antipsychotics. Olanzapine was most frequently prescribed in both high dosing (55%) and APP (40%).

CONCLUSIONS

There is a high prevalence of high-dose prescribing and APP in this NZ setting.

Treatment patterns and appropriateness of antipsychotic prescriptions in patients with schizophrenia

Schizophrenia is a chronic mental condition presenting a wide range of symptoms. Although it has a low prevalence compared to other mental conditions, it has a negative impact on social and occupational functions. This study aimed to assess the appropriateness of antipsychotic medications administered to schizophrenic patients and describe current treatment patterns for schizophrenia. A retrospective cohort study was conducted in all patients over the age of 15 with an active diagnosis of schizophrenia and treated with antipsychotics between 2008 and 2013 in the Valencia region. A total of 19,718 patients were eligible for inclusion. The main outcome assessed was inappropriateness of the pharmacotherapeutic management, including polypharmacy use. Altogether, 30.4% of patients received antipsychotic polypharmacy, and 6.8% were prescribed three or more antipsychotics. Overdosage affected 318 individuals (1.6%), and 21.5% used concomitant psychotropics without an associated psychiatric diagnosis. Women and people with a comorbid condition like anxiety or depression were less likely to receive antipsychotic polypharmacy. In contrast, increased polypharmacy was associated with concomitant treatment with other psychoactive drugs, and only in user on maintenance therapy, with more visits to the mental health hospital. Overall, we observed a high level of inappropriateness in antipsychotic prescriptions. Greater adherence to guidelines could maximize the benefits of antipsychotic medications while minimizing risk of adverse effects.

A qualitative exploration of factors contributing to non-guideline adherent antipsychotic polypharmacy

BACKGROUND

Antipsychotic polypharmacy ("polypharmacy") involves the concurrent prescribing of two or more antipsychotics for managing schizophrenia. It occurs frequently despite there being limited clinical evidence for this practice and an increased risk of adverse events. Little is understood about why it occurs outside of treatment guidelines, highlighting a current research gap.

OBJECTIVE

To explore the factors contributing to non-evidence based polypharmacy practice and possible strategies for addressing these factors.

METHODS

Three focus groups were conducted between June and August 2018 with doctors and nurses employed at a mental health unit of a Western Australian public hospital. Participants were asked about their perceptions of polypharmacy, why it occurred and what could limit its prevalence. Thematic inductive analysis was mapped to the Theoretical Domains Framework to identify key underlying themes and to establish potential enablers and barriers for practice change.

RESULTS

Participants understood the risks of polypharmacy and perceived it to largely be perpetuated by external factors, out of which two key themes emerged: system-related issues (e.g.: communication failures whereby de-prescribing plans are not actioned); and patient-related issues (e.g.: misinformed views translating to medication-seeking behaviour). This led to the third theme: a disconnect between clinicians' knowledge and their practices (i.e.: being aware of Australian evidence-based guideline recommendations yet acknowledging polypharmacy still occurred due to the aforementioned issues). Strategies suggested to address these issues included developing medication management plans to bridge communication gaps and managing patients' medication expectations with education.

CONCLUSIONS

Management of schizophrenia is complex, requiring consideration of many patient-related and systemic factors. Polypharmacy has a place in certain contexts, however, must be well considered and closely monitored to allow for early identification of opportunities to rationalise (i.e.: de-prescribe) therapy, where appropriate. Future research objectives will centre on implementing strategies identified from these focus groups to optimise patient outcomes.

Defining polypharmacy: in search of a more comprehensive determination method applied in a tertiary psychiatric hospital

AIMS

This cross-sectional pharmacoepidemiologic study examined the prevalence of polypharmacy and psychotropic polypharmacy among inpatients in a tertiary psychiatric hospital in Belgium.

METHODS

Current prescriptions of all inpatients suffering from mental disorders were extracted from the hospital Computerized Physician Order Entry. Two methods were used to examine definitive polypharmacy (defined as the concomitant use of at least five medicines): number of medicines per active component and per prescription. Psychotropic polypharmacy was defined as the concomitant use of at least two psychotropic medicines, based on the first counting, i.e., per active component.

RESULTS

In 292 included patients, the prevalence of definitive polypharmacy was 65.8%, with a mean number of 6.8 ± 4.2 medicines per patient. The most prevalent medicines were related to the central nervous system (55.7%), followed by medicines related to the gastro-intestinal (17.6%) and cardiovascular (9.4%) systems. A prevalence of psychotropic polypharmacy of 78.1% was observed, with a mean of 3.0 ± 1.7 psychotropic medicines per patient. Psychotropic polypharmacy was classified in same-class (71.5%), multi-class (82.5%), augmentation (20.6%), and adjuvant (35.5%) polypharmacy.

CONCLUSION

These findings are consistent with previous reports of highly prevalent polypharmacy in patients with mental disorders. Although, in some cases, polypharmacy can be an important part of good clinical practice, the high prevalence of both polypharmacy and psychotropic polypharmacy emphasizes that attention must be paid to the potentially associated risks. Consensus on the definition and method of determination of polypharmacy is needed to support further research.