A new lexicon for polypharmacy: Implications for research, practice, and education

Geriatric Pharmacotherapy Case Series: Poly-Provider Leading to Polypharmacy

Background: This case study reviews the complicated treatment of an older person under the care of numerous specialists in the ambulatory care setting. As various providers made concurrent changes in pharmacotherapy without communication with other providers, the patient experienced acute changes and decompensation. Assessment: Polypharmacy played a significant role in the acute decompensation of the patient. Changes made in the context of specific specialties inadvertently had a negative impact on other disease states. Outcome: Intentional communication between all providers on the patient’s health care team resulted in a deeper understanding of the overall plan and therapeutic goals. Care synchronization ultimately improved patient outcomes. The clinical pharmacy team provided multiple pharmacotherapy recommendations to improve pain and anxiety without jeopardizing safety and therapeutics for other disease states. These interventions provided a key element that streamlined and improved patient-centered care. Conclusion: In this case, poly-provider was responsible for polypharmacy that significantly impacted the patient’s care and quality of life. Pharmacists and the pharmacists’ patient care process play a significant role in improving patient-centered care by identifying medication changes and potential side effects, especially in the wake of interventions by multiple providers.

Trends and Determinants of Polypharmacy and Potential Drug-Drug Interactions at Discharge From Hospital Between 2009-2015

BACKGROUND

Polypharmacy (PP) and excessive polypharmacy (EPP) are increasingly common and associated with risk of drug-drug interactions (DDIs). We aimed to measure the trends and determinants of PP and DDIs among patients discharged from the Department of Internal Medicine of the Lausanne University Hospital.

METHODS

The retrospective study included 17,742 adult patients discharged between 2009 and 2015. Polypharmacy and EPP were defined as the concomitant prescription of five or more and ten or more drugs, respectively. Drug-drug interactions were defined as any combination of a drug metabolized by a cytochrome P450 or P-glycoprotein, and a drug considered as strong inductor or inhibitor of the corresponding enzyme was defined as a potential interaction.

RESULTS

Three most commonly classes of drugs prescribed were "alimentary tract and metabolism (including insulins)," "nervous system," and "blood and blood forming organs." Polypharmacy decreased from 45% in 2009 to 41% in 2015, whereas EPP increased from 40% to 46%. In 2015, 13% of patients received 15 or more drugs. Age, coming from other health care settings, higher Charlson Index, number of comorbidities, and quartiles of length of stay were significantly and independently associated with PP and EPP. The risk of having at least one DDI decreased from 67.0% (95% confidence interval = 64.8-69.0) in 2009 to 59.3% (57.6-62.0) in 2015 (P < 0.001). Multivariate analysis showed number of drugs (odds ratio and 95% confidence interval = 3.68 [3.3-4.1], 9.39 [8.3-10.6], and 20.5 [17.3-28.4] for [5-9], [10-14], and 15+ drugs, respectively), gastrointestinal disease (3.13 [2.73-3.58]), and cancer (1.37 [1.18-1.58]) to be positively associated, and lung (0.82 [0.74-0.90]) and endocrinological (0.62 [0.52-0.74]) diseases to be negatively associated with risk of DDI.

CONCLUSIONS

The pattern of drug prescription has changed and most prescribed groups increased during the study period. Excessive polypharmacy is increasing among hospital patients. The decrease in the overall risk of DDI could be due to an improved management of multidrug therapy.

An overview of prevalence, determinants and health outcomes of polypharmacy

A high rate of polypharmacy is, in part, a consequence of the increasing proportion of multimorbidity in the ageing population worldwide. Our understanding of the potential harm of taking multiple medications in an older, multi-morbid population, who are likely to be on a polypharmacy regime, is limited. This is a narrative literature review that aims to appraise and summarise recent studies published about polypharmacy. We searched MEDLINE using the search terms polypharmacy (and its variations, e.g. multiple prescriptions, inappropriate drug use, etc.) in titles. Systematic reviews and original studies in English published between 2003 and 2018 were included. In this review, we provide current definitions of polypharmacy. We identify the determinants and prevalence of polypharmacy reported in different studies. Finally, we summarise some of the findings regarding the association between polypharmacy and health outcomes in older adults, with a focus on frailty, hospitalisation and mortality. Polypharmacy was most often defined in terms of the number of medications that are being taken by an individual at any given time. Our review showed that the prevalence of polypharmacy varied between 10% to as high as around 90% in different populations. Chronic conditions, demographics, socioeconomics and self-assessed health factors were independent predictors of polypharmacy. Polypharmacy was reported to be associated with various adverse outcomes after adjusting for health conditions. Optimising care for polypharmacy with valid, reliable measures, relevant to all patients, will improve the health outcomes of older adult population.

An Increasing Trend in the Prevalence of Polypharmacy in Sweden: A Nationwide Register-Based Study

Aim

Polypharmacy is becoming a global health problem. The aims of this study were to evaluate the temporal trends in the prevalence of polypharmacy in Sweden and to explore polypharmacy disparities by age, gender, education, and immigration status.

Methods

Polypharmacy and excessive polypharmacy were evaluated using data extracted from the Swedish Prescribed Drug Register between 2006 and 2014. Polypharmacy was defined as being exposed to five or more drugs and excessive polypharmacy was defined as being exposed to 10 or more drugs during 1 month respectively. Average annual percent change (AAPC) was calculated using Joinpoint Statistical Software.

Results

The prevalence of polypharmacy increased from 16.9% in 2006 to 19.0% in 2014 with an AAPC of 1.3; the prevalence of excess polypharmacy increased from 3.8% in 2006 to 5.1% in 2014 with an AAPC of 3.4. The prevalence of polypharmacy and excessive polypharmacy increased dramatically with age and peaked up to 79.6% and 36.4% in individuals aged 90 and above respectively. Females and individuals with lower education level were associated with a higher rate of polypharmacy and excessive polypharmacy. Immigrants from Middle-Eastern countries had the highest rate of polypharmacy and excessive polypharmacy, whereas individuals from Western Europe countries had the lowest rate.

Conclusion

The prevalence of polypharmacy has increased gradually in Sweden during the past decade. Individuals with older age, female sex, or lower education have a higher rate of polypharmacy and excessive polypharmacy. Immigrants from Middle-Eastern countries showed a higher rate of polypharmacy.

Failure to Reach a Consensus in Polypharmacy Definition: An Obstacle to Measuring Risks and Impacts-Results of a Literature Review

INTRODUCTION

The risk of polypharmacy is on the rise in most industrialized countries, threatening to burden their health systems. Although many definitions exist and numerous concepts are found in literature as synonyms, the phenomenon of polypharmacy remains poorly defined. The aim of this literature review is to provide an overview of available definitions of polypharmacy, to analyse their convergences and divergences and to discuss the consequences on the assessment of the problem.

METHODS

A literature review was conducted to identify all published systematic reviews on definitions of polypharmacy available via Scopus and Pubmed databases. The Assessment of Multiple Systematic Reviews (AMSTAR) tool was used to appraise the methodological quality of the selected reviews. Available definitions and other characteristics were extracted; summarised in a table and analysed.

RESULTS

Six systematic reviews were identified. They were published between 2000 and 2018. Three focussed on definitions of polypharmacy in the elderly; two in the general population and one in children. The strategy adopted in reviews is more rigorous in the most recent ones. However, they remain, at best, partially exhaustive. The definitions found in the literature used two main approaches, either (i) quantitative, applying varying thresholds and types of polypharmacy based on the number of medications being taken by the patient (ii) qualitative, based on the clinical indications and effects of a given drug regimen, with a growing number of characteristics to describe polypharmacy. The term "inappropriate" is increasingly associated with polypharmacy especially in studies that aimed to use this definition to identify possible solutions for healthcare providers in the field related to aging.

CONCLUSION

This review confirms a high variability and an evolution in the approaches defining "polypharmacy" in the absence of a consensus following standardized criteria. That makes it very difficult to estimate and measure the outcomes associated with this phenomenon.

Changing trends in epidemiology and management of facial trauma in a Swiss geriatric population

OBJECTIVE

To assess the prevalence and surgical treatment of facial fractures in a Swiss population aged 65 and over.

BACKGROUND

The knowledge of the characteristics of geriatric trauma may help to prevent injuries and better allocate clinical resources for the management of multimorbid patients.

MATERIAL AND METHODS

This study retrospectively evaluated a cohort of 181 patients who presented at the Bern University Hospital in Switzerland from May 2012 to September 2016. Data on age, gender, aetiology and type of trauma, treatment and complications, co-morbidities and associated injuries were obtained.

RESULTS

Women were most frequently affected (55.2%). Mean age was 80 years. Zygomatic complex fractures were the most frequent type of fractures (37%), followed by isolated orbital fractures (27.6%). Falls were the most common cause of trauma (76.1%). Thirty-five per cent of all patients were taking anticoagulation or platelet aggregation medication. Hospitalisation was required in 88.4%, whereby 92.3% of the patients underwent surgical treatment. Surgery had to be performed immediately in three cases to treat compression of the optic nerve. Median hospital length of stay was 4 days, with 68% of patients returning to a domestic environment and 32% being transferred to another institution for further treatment.

CONCLUSION

The most common cause of facial injuries is a fall while standing in a domestic environment. Midface fractures were the most common type of fractures.

Huntington's disease: novel therapeutic perspectives hanging in the balance

INTRODUCTION

Huntington's disease (HD), an autosomal dominant neurodegenerative disorder caused by an expansion of CAG repeats in the huntingtin gene, has long been characterized by the presence of motor symptoms due to the loss of striatal projection neurons. Cognitive dysfunction and neuropsychiatric symptoms are also present and they occur in the absence of cell death in most mouse models, pointing to neuronal dysfunction and abnormal synaptic plasticity as causative mechanisms. Areas covered: Here, we focus on those common mechanisms altered by the presence of mutant huntingtin affecting corticostriatal and hippocampal function as therapeutic targets that could prove beneficial to ameliorate both cognitive and motor function in HD. Specifically, we discuss the importance of reestablishing the balance in (1) synaptic/extrasynaptic N-methyl-D-aspartate receptor signaling, (2) mitochondrial dynamics/trafficking, (3) TrkB/p75^NTR signaling, and (4) transcriptional activity. Expert opinion: Mutant huntingtin has a broad impact on multiple cellular processes, which makes it very challenging to design a curative therapeutic strategy. As we point out here, novel therapeutic interventions should look for multi-purpose drugs targeting common and early affected processes leading to corticostriatal and hippocampal dysfunction that additionally operate in a feedforward vicious cycle downstream the activation of extrasynaptic N-methyl-D-aspartate receptor.

Updates in nutrition and polypharmacy

PURPOSE OF REVIEW

Medications have the potential to affect nutritional status in negative ways, especially as the number of medications increase. The inter-relation between polypharmacy and malnutrition is complex and not fully delineated in previous studies. More research has been done and compiled in the last year, which helps to clarify this relationship. This review brings together the most recent literature with the previous research to help healthcare providers to better assess and manage medication therapy in older adults.

RECENT FINDINGS

Recent evidence confirms a synergistic negative effect of polypharmacy and malnutrition on outcomes of older adults. In addition, several drug classes, including common antihypertensive agents, acetylcholinesterase inhibitors, multivitamins, proton pump inhibitors, HMG-CoA reductase inhibitors (statins), antiplatelet agents and metformin, have been implicated in important drug-nutrient interactions. These are reviewed in detail here. Ongoing research endeavors are described.

SUMMARY

Healthcare practitioners can use this review to identify potentially inappropriate medications and patients at highest risk of experiencing a medication-related adverse reaction in order to systematically deprescribe these high-risk medications.

Prevalence and determinants of polypharmacy in Switzerland: data from the CoLaus study

Background

Polypharmacy is a frequent condition, but its prevalence and determinants in the Swiss mid-aged population are unknown. We aimed to evaluate the prevalence and determinants of polypharmacy in a large Swiss mid-aged population-based sample.

Methods

Data from 4938 participants of the CoLaus study (53% women, age range 40–81 years) were collected between 2009 and 2012. Polypharmacy was defined by the regular use of five or more drugs.

Results

Polypharmacy was reported by 580 participants [11.8%, 95% confidence interval (10.9; 12.6)]. Participants on polypharmacy were significantly older (mean ± standard deviation: 66.0 ± 9.1 vs. 56.6 ± 10.1 years), more frequently obese (35.9% vs. 14.7%), of lower education (66.6% vs. 50.7%) and former smokers (46.7% vs. 36.4%) than participants not on polypharmacy. These findings were confirmed by multivariate analysis: odds ratio and (95% confidence interval) for age groups 50–64 and 65–81 relative to 40–49 years: 2.90 (2.04; 4.12) and 10.3 (7.26; 14.5), respectively, p for trend < 0.001; for low relative to high education: 1.56 (1.17; 2.07); for overweight and obese relative to normal weight participants: 2.09 (1.65; 2.66) and 4.38 (3.39; 5.66), respectively, p for trend < 0.001; for former and current relative to never smokers: 1.42 (1.14, 1.75) and 1.63 (1.25, 2.12), respectively, p for trend < 0.001.

Conclusion

One out of nine participants of our sample is on polypharmacy. Increasing age, body mass index, smoking and lower education independently increase the likelihood of being on polypharmacy.

Electronic supplementary material

The online version of this article (10.1186/s12913-017-2793-z) contains supplementary material, which is available to authorized users.

What is polypharmacy? A systematic review of definitions

BACKGROUND

Multimorbidity and the associated use of multiple medicines (polypharmacy), is common in the older population. Despite this, there is no consensus definition for polypharmacy. A systematic review was conducted to identify and summarise polypharmacy definitions in existing literature.

METHODS

The reporting of this systematic review conforms to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) checklist. MEDLINE (Ovid), EMBASE and Cochrane were systematically searched, as well as grey literature, to identify articles which defined the term polypharmacy (without any limits on the types of definitions) and were in English, published between 1st January 2000 and 30th May 2016. Definitions were categorised as i. numerical only (using the number of medications to define polypharmacy), ii. numerical with an associated duration of therapy or healthcare setting (such as during hospital stay) or iii. Descriptive (using a brief description to define polypharmacy).

RESULTS

A total of 1156 articles were identified and 110 articles met the inclusion criteria. Articles not only defined polypharmacy but associated terms such as minor and major polypharmacy. As a result, a total of 138 definitions of polypharmacy and associated terms were obtained. There were 111 numerical only definitions (80.4% of all definitions), 15 numerical definitions which incorporated a duration of therapy or healthcare setting (10.9%) and 12 descriptive definitions (8.7%). The most commonly reported definition of polypharmacy was the numerical definition of five or more medications daily (n = 51, 46.4% of articles), with definitions ranging from two or more to 11 or more medicines. Only 6.4% of articles classified the distinction between appropriate and inappropriate polypharmacy, using descriptive definitions to make this distinction.

CONCLUSIONS

Polypharmacy definitions were variable. Numerical definitions of polypharmacy did not account for specific comorbidities present and make it difficult to assess safety and appropriateness of therapy in the clinical setting.

Current and future perspectives on the management of polypharmacy

BACKGROUND

Because of ageing populations, the growth in the number of people with multi-morbidity and greater compliance with disease-specific guidelines, polypharmacy is becoming increasingly common. Although the correct drug treatment in patients with complex medical problems can improve clinical outcomes, quality of life and life expectancy, polypharmacy is also associated with an increased risk of adverse drug events, some severe enough to result in hospital admission and even death. Hence, having systems in place to ensure that medications are started only when there is a suitable indication, ensuring patients are fully aware of the benefits and complications that may arise from their treatment, and reviewing patients regularly to ensure their medication regime remains appropriate, are essential.

DISCUSSION

The development and rapid uptake of electronic patient records - particularly in primary care settings where the majority of prescribing takes place - makes monitoring of patients more straightforward than in the past; and allows identification of sub-groups of patients at particularly high risk of adverse drug events and complications. It also facilitates 'deprescribing' the process by which medications are reviewed and stopped if not clinically beneficial. In recent years, we have also seen the development of smartphone 'apps' to improve communication between patients and healthcare professionals, improve people's understanding of their conditions and their treatment, and maintain a record of changes made to patient's medication. In the longer term, developments such as the introduction of artificial intelligence and clinical decision support systems also have the potential to improve prescribing and minimise the risks from polypharmacy. Finally, there is considerable scope to improve the quality of prescribing and reduce risks from poly-pharmacy using non-medical groups such as pharmacists, specialist nurses and physician assistants. Polypharmacy has increased in recent decades and will continue to increase as populations age and the number of people with multiple long-term conditions increases. As with all areas of medicine, the evidence-base in this area continues to evolve. Further trials on the impact on patients with polypharmacy of new interventions such as technology-based solutions and the use of different professional groups are needed to improve the evidence-base in this area.

The Association between Polypharmacy and Dementia: A Nested Case-Control Study Based on a 12-Year Longitudinal Cohort Database in South Korea

Dementia is a major concern among growing chronic diseases in the aging society and its association with polypharmacy has not been adequately assessed. The objective of this study was to determine the association between polypharmacy and dementia through multiple statistical approaches. We conducted a nested case-control study for newly diagnosed dementia cases using the South Korean National Health Insurance Service sample cohort database (2002–2013, n = 1,025,340). Interactions between polypharmacy (an average use of ≥5 prescription drugs daily) and comorbidities or potentially inappropriate medications (PIMs) were tested. The odds ratios (ORs) for dementia were analyzed according to the presence of comorbidities, PIM uses, the average number of prescribed daily drugs, and significant interactions with polypharmacy using univariate and multiple logistic regression analyses. A higher prevalence of comorbidities, history of PIM use, higher PIM exposure, and higher proportion of polypharmacy were noted among cases than in controls. In the univariate analysis, the OR for dementia increased significantly with the increase in the number of prescribed drugs [1–<5 drugs: 1.72, 95% confidence interval (CI): 1.56–1.88; 5–<10 drugs: 2.64, 95% CI: 2.32–3.05; ≥10 drugs: 3.35, 95% CI: 2.38–4.71; <1 drug used as reference]. Polypharmacy was correlated with comorbidities and PIM use, and significant interactions were observed between polypharmacy and anticholinergics; H2-receptor antagonists; and comorbidities such as hypertension, peripheral or cerebrovascular disease, congestive heart failure, hemiplegia, diabetes, depression, all other mental disorders, chronic obstructive pulmonary disease, peptic ulcer disease, and chronic liver disease (p<0.001). In the multiple regression analysis, most cases exhibited increasing ORs for dementia with increasing polypharmacy levels. Moreover, the increase in OR was more evident in the absence of drugs or comorbidities that showed significant interactions with polypharmacy than in their presence. Polypharmacy increases the risk of PIM administration, and as some PIMs may have cognition-impairing effects, prolonged polypharmacy may result in dementia. Therefore, efforts are needed to limit or decrease the prescription of medications that have been associated with risk of dementia in the elderly.

Why is polypharmacy increasing in aged care facilities? The views of Australian health care professionals

RATIONALE, AIMS AND OBJECTIVES

The prevalence of polypharmacy in residential aged care facilities (RACFs) is high and increasing. Although not necessarily inappropriate, polypharmacy has been associated with drug interactions, adverse drug events, geriatric syndromes and hospital admissions. The aim of this study was to identify and prioritize factors contributing to the increasing prevalence of polypharmacy in RACFs.

METHODS

Seventeen health care professionals from metropolitan and regional Victoria and South Australia identified and prioritized factors using a modified nominal group technique.

RESULTS

The top five factors ranked from most important to fifth most important were 'changes in resident mix', 'increasing numbers of prescribers and the reluctance of one prescriber to discontinue a medicine commenced by another prescriber', 'better adherence to clinical practice guidelines', 'increasing reliance on locums' and 'greater recognition and pharmacological management of pain'.

CONCLUSIONS

Reasons for the increase in polypharmacy are multifactorial. Understanding the factors contributing to polypharmacy may help to guide future research and develop interventions to manage polypharmacy in RACFs.

Prevalence and factors associated with potentially inappropriate prescriptions among older patients at hospital discharge

RATIONALE, AIMS AND OBJECTIVES

Explicit criteria have been used worldwide to identify suboptimal prescribing such as potentially inappropriate prescriptions (PIPs). The objective of our study was to determine prevalence, types and factors associated with PIPs in older people discharged from an Albanian hospital.

METHOD

Retrospective, cross-sectional study conducted among patients aged 60 years and more discharged from the Cardiology and Internal Medicine departments of the University Hospital Center 'Mother Theresa' Tirana during 2013. PIPs were identified by using Beers (2012 update) and STOPP criteria (2008 and 2014 versions). Chi-square analysis and Student Test were performed. Crude and adjusted odds ratios with their 95% confidence intervals were estimated by logistic regression analysis.

RESULTS

Medical files for 319 patients were assessed. The median number of drugs prescribed was 7.8 (SD 2.2). PIPs prevalence at hospital discharge was 34.5% (95% CI 27.5-42.2%; 110 patients) according to both Beers and STOPP version 1 criteria. STOPP version 2 identified 201 (63.0%) patients with at least one PIP (95% CI 55.2-70.2%; 312 PIPs). The drugs more frequently involved in PIPs were aspirin, spironolactone, benzodiazepines, digoxin and methyldopa. The odds of having a PIP were higher in patients discharged from Internal Medicine (P < 0.005). The PIP index was 0.056%, 0.054% and 0.125% respectively for Beers, STOPP 2008 and STOPP 2014 criteria. A significant positive correlation was found between the number of prescribed drugs and PIP occurrence.

CONCLUSIONS

Our study found that between one and two out of three older patients has at least one PIP among the treatment prescribed at hospital discharge, depending on the tool used for detection. The high frequency of PIPs suggests the urgent need for interventions to reduce them.

Polypharmacy and potentially inappropriate medication use in geriatric oncology

Polypharmacy is a highly prevalent problem in older persons, and is challenging to assess and improve due to variations in definitions of the problem and the heterogeneous methods of medication review and reduction. The purpose of this review is to summarize evidence regarding the prevalence and impact of polypharmacy in geriatric oncology patients and to provide recommendations for assessment and management. Polypharmacy has somewhat variably been incorporated into geriatric assessment studies in geriatric oncology, and polypharmacy has not been consistently evaluated as a predictor of negative outcomes in patients with cancer. Once screened, interventions for polypharmacy are even more uncertain. There is a great need to create standardized interventions to improve polypharmacy in geriatrics, and particularly in geriatric oncology. The process of deprescribing is aimed at reducing medications for which real or potential harm outweighs benefit, and there are numerous methods to determine which medications are candidates for deprescribing. However, deprescribing approaches have not been evaluated in older patients with cancer. Ultimately, methods to identify polypharmacy will need to be clearly defined and validated, and interventions to improve medication use will need to be based on clearly defined and standardized methods.

Polypharmacy and potentially inappropriate prescriptions identified by Beers and STOPP criteria in co-morbid older patients at hospital discharge

RATIONALE, AIMS AND OBJECTIVES

The objective of this study was to evaluate the prevalence of potentially inappropriate prescriptions (PIP) and the association with polypharmacy (more than six drugs prescribed) in co-morbid older patients in a critical moment of care transition such as hospital discharge by means of two explicit criteria (Beers 2012 and STOPP 2008).

METHOD

Cross-sectional study carried out in an older patients' population (≥65 years old) discharged from a university hospital in Spain. We recorded patients' information regarding demographics, diagnosis, drugs prescribed and associated pathological conditions and calculated the Charlson co-morbidity index. Data were obtained from the electronic medical records of hospital discharge. Beers (2012) and STOPP criteria (2008) were applied for PIP detection. The strength of association between polypharmacy and the presence of PIP was assessed by calculating the crude and adjusted odds ratio and its 95% confidence interval.

RESULTS

From 1004 patients of a 15% random sample, just 624 that fulfilled the inclusion criteria were included in the study. The number of prescribed drugs was a risk factor for PIP according to both criteria, even after adjusting for confounding variables. PIP frequency was higher in patients who received more than 12 medications (Beers: 34.8%, STOPP: 54.4%). Each additional medication increased the risk of PIP by 14 or 15% (Beers or STOPP).

CONCLUSIONS

Our results suggest that the strategies used for PIP reduction in co-morbid older patients should focus on the management of polypharmacy. Medication review at hospital discharge is highly recommended for patients taking more than six drugs.

Prevalence and clinical features associated with bipolar disorder polypharmacy: a systematic review

BACKGROUND

Uncertainty exists regarding the prevalence and clinical features associated with the practice of polypharmacy in bipolar disorder (BD), warranting a systematic review on the matter.

METHODS

Three authors independently searched major electronic databases from inception till September 2015. Articles were included that reported either qualitative or quantitative data about the prevalence and clinical features associated with polypharmacy in adult cases of BD.

RESULTS

The operative definitions of polypharmacy adopted across varying studies varied, with concomitant use of two or more psychotropic medications or use of four or more psychotropic medications at once being the most common and the most reliable, respectively. Regardless of type or current mood episode polarity of BD, prevalence rates up to 85% and 36% were found using the most permissive (two or more medications at once) and the most conservative (four or more) operative definitions for polypharmacy, respectively. Point prevalence prescription rates of one or more antidepressant or antipsychotic as part of a polypharmacy regimen occurred in up to 45% or 80% of the cases, respectively, according to the most permissive definition of polypharmacy. In contrast, lithium prescription rates ranged from 13% to 33% in BD patients receiving polypharmacy according to conservative and permissive definitions, possibly suggesting a reduced need for augmentation of combination strategies for those cases of BD with a favorable lifetime lithium response and/or long-lasting treatment as well as less likelihood of lithium response over the time most severe cases possibly exposed to a more complex polypharmacy overall.

LIMITATIONS

"Apples and oranges" bias; publication bias for most recently introduced compounds.

CONCLUSION

Polypharmacy is common among people with BD across varying type and mood episode phases of illness. Special population, including BD patients at high risk of familial load for suicidal behavior, solicit further research as well as the plausible "protective" role of lithium toward polypharmacy in BD. The PROSPERO registration number is CRD42014015084.