Complexity of medication use in the Veterans Affairs healthcare system: Part I: Outpatient use in relation to age and number of prescribers

Prevalence and factors associated with polypharmacy: a systematic review and Meta-analysis

Introduction

Polypharmacy is commonly associated with adverse health outcomes. There are currently no meta-analyses of the prevalence of polypharmacy or factors associated with polypharmacy. We aimed to estimate the pooled prevalence of polypharmacy and factors associated with polypharmacy in a systematic review and meta-analysis.

Methods

MEDLINE, EMBASE, and Cochrane databases were searched for studies with no restrictions on date. We included observational studies that reported on the prevalence of polypharmacy among individuals over age 19. Two reviewers extracted study characteristics including polypharmacy definitions, study design, setting, geography, and participant demographics. The risk of bias was assessed using the Newcastle-Ottawa Scales. The main outcome was the prevalence of polypharmacy and factors associated with polypharmacy prevalence. The pooled prevalence estimates of polypharmacy with 95% confidence intervals were determined using random effects meta-analysis. Subgroup analyses were undertaken to evaluate factors associated with polypharmacy such as polypharmacy definitions, study setting, study design and geography. Meta-regression was conducted to assess the associations between polypharmacy prevalence and study year.

Results

106 full-text articles were identified. The pooled estimated prevalence of polypharmacy in the 54 studies reporting on polypharmacy in all medication classes was 37% (95% CI: 31-43%). Differences in polypharmacy prevalence were reported for studies using different numerical thresholds, study setting, and publication year. Sex, study geography, study design and geographical location were not associated with differences in polypharmacy prevalence.

Discussion

Our review highlights that polypharmacy is common particularly among older adults and those in inpatient settings. Clinicians should be aware of populations who have an increased likelihood of experiencing polypharmacy and efforts should be made to review the appropriateness of prescribed medications and occurrence of adverse effects potentially associated with polypharmacy.

Conclusions and implications

Clinicians should be aware of the common occurrence of polypharmacy and undertake efforts to minimize inappropriate polypharmacy whenever possible.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03279-x.

Why Are Patients With COVID-19 at Risk for Drug-Drug Interactions?

The goal of this column is to provide information to health care professionals about drug-drug interactions (DDIs) and why DDIs are important to consider in those at serious risk of illness with Coronavirus Disease 2019 (COVID-19). Important considerations discussed in this column include the frequency and complexity of multiple medication use, particularly important for the older patient who often has multiple comorbid illnesses. The column covers the following issues: (1) Why patients at high risk for serious illness from COVID-19 are also at high risk for DDIs. (2) Application of results of pharmacoepidemiological studies to the population at risk for serious COVID-19 illness. (3) Mechanisms underlying DDIs, frequency and potential complexity of DDIs, and how DDIs can present clinically. (4) Methods for preventing or mitigating DDIs. (5) An introduction to the University of Liverpool drug interaction checker as a tool to reduce the risk of adverse DDIs while treating patients for COVID-19. Commentary is also provided on issues related to specific psychiatric and nonpsychiatric medications a patient may be taking. A subsequent column will focus on DDIs between psychiatric medications and emerging COVID-19 treatments, as a detailed discussion of that topic is beyond the scope of this column.

Drug-drug Interactions in Psychiatric Practice, Part 1: Reasons, Importance, and Strategies to Avoid and Recognize Them

This column begins a series exploring drug-drug interactions (DDIs) with a special emphasis on psychiatric medications. As explained in this column, this topic is important for multiple reasons. First, a large percentage of the population is receiving psychiatric medications. Second, these patients are likely to be on multiple medications which means that they are at risk for an adverse DDI. Third, DDIs may occur but not be recognized even though they have significant health care consequences for the patient. Fourth, these consequences can range from a catastrophic outcome to more everyday clinical problems involving a myriad of presentations as enumerated in this column. Also discussed in this column is the fact that all drugs, including psychiatric medications, interact on the basis of their pharmacodynamics and pharmacokinetics rather than their therapeutic use. Therefore, psychiatric medications may interact with medications prescribed for nonpsychiatric reasons as well as with other psychiatric medications. Tables are included that explain reasons for multiple medication use and principles to follow to minimize the risk of adverse DDIs.

Economic outcomes of pharmacist-physician medication therapy management for polypharmacy elderly: A prospective, randomized, controlled trial

BACKGROUND/PURPOSE

With an increasing geriatric population, the need for effective management of chronic conditions and medication use in the elderly is growing. Medication use in the elderly presents significant challenges due to changes in pharmacodynamic and pharmacokinetic profiles. We aimed to examine the impact of a collaborative physician-pharmacist medication therapy management (MTM) program for polypharmacy elderly patients.

METHODS

Elderly patients with multiple chronic conditions on polypharmacy were enrolled in this prospective, randomized, and controlled study over 16 months of implementation. The intervention group consisted of patients randomized to a collaborative pharmacist-physician MTM program. They were monitored continuously by a clinical pharmacist, while patients in the control group received only usual care with follow-up assessment. Primary outcome was economic differences, measured in total medical expenditure. Secondary outcomes of clinical and humanistic effects were compared between the two groups.

RESULTS

The total number of enrolled patients was 87 and 91 in the MTM and usual groups, respectively. The difference-in-difference estimate on medical expenditure during the 16-month implementation period was $3,758,373 New Taiwan Dollars ($127,015 US Dollars) less than the usually care group. Impact was also seen in humanistic outcomes while lipid profiles and mortality trended toward improvement.

CONCLUSION

The pharmacist-physician collaborative MTM program for polypharmacy elderly had significant cost savings and improvement in humanistic measures, demonstrating the importance of clinical pharmacists and MTM programs for elderly patients in Taiwan. The results suggest the possibility of clinical benefits, but the study was not substantially powered to find a statistical difference.

Epigenetic Effects of PTSD Remediation in Veterans Using Clinical Emotional Freedom Techniques: A Randomized Controlled Pilot Study

PURPOSE

To assess the feasibility of measuring changes in gene expression associated with post-traumatic stress disorder (PTSD) treatment using emotional freedom techniques (EFT).

DESIGN

Participants were randomized into an EFT group receiving EFT and treatment as usual (TAU) throughout a 10-week intervention period and a group receiving only TAU during the intervention period and then receiving EFT.

SETTING

A community clinic and a research institute in California.

PARTICIPANTS

Sixteen veterans with clinical levels of PTSD symptoms.

INTERVENTION

Ten hour-long sessions of EFT.

MEASURES

Messenger RNA levels for a focused panel of 93 genes related to PTSD. The Symptom Assessment 45 questionnaire, Hospital Anxiety and Depression Scale, Insomnia Severity Scale, SF-12v2 for physical impairments, and Rivermead Postconcussion Symptoms Questionnaire.

ANALYSIS

Pre-, posttreatment, and follow-up mean scores on questionnaires were assessed using repeated measures 1-way analysis of variance. A Student t test and post hoc analyses were performed on gene expression data.

RESULTS

Post-traumatic stress disorder symptoms declined significantly in the EFT group (-53%, P < .0001). Participants maintained their gains on follow-up. Significant differential expression of 6 genes was found ( P < .05) when comparing the expression levels before and after the intervention period in participants receiving EFT.

CONCLUSION

Study results identify candidate gene expression correlates of successful PTSD treatment, providing guidelines for the design of further studies aimed at exploring the epigenetic effects of EFT.

Prediction of individual response to antidepressants and antipsychotics: an integrated concept

In both clinical trials and daily practice, there can be substantial inter- and even intraindividual variability in response--whether beneficial or adverse--to antidepressants and antipsychotic medications. So far, no tools have become available to predict the outcome of these treatments in specific patients. This is because the causes of such variability are often not known, and when they are, there is no way of predicting the effects of their various potential combinations in an individual. Given this background, this paper presents a conceptual framework for understanding known factors and their combinations so that eventually clinicians can better predict what medication(s) to select and at what dose they can optimize the outcome for a given individual. This framework is flexible enough to be readily adaptable as new information becomes available. The causes of variation in patient response are grouped into four categories: (i) genetics; (ii) age; (iii) disease; and (iv) environment (internal). Four cases of increasing complexity are used to illustrate the applicability of this framework in a clinically relevant way In addition, this paper reviews tools that the clinician can use to assess for and quantify such inter- and intraindividual variability. With the information gained, treatment can be adjusted to compensate for such variability, in order to optimize outcome. Finally, the limitations of existing antidepressant and antipsychotic therapy and the way they reduce current ability to predict response is discussed.

Does the Elderly's Number of Prescribed Medications across Months Matter? National Cohort versus Single-Center Cohort

OBJECTIVES

To investigate the monthly number of prescribed medication (NPM) patterns among different elderly populations and the factors associated with monthly NPM changes.

METHODS

This retrospective cohort study was conducted using the databases obtained from National Health Insurance Research Databases and a 2000-bed academic medical center in Taiwan (i.e., single-center cohort). We compared the monthly NPMs, demographic characteristics, disease states, and health care contacts among the National Health Insurance elderly cohorts in 2006 and 2007, and for those elderly in the national and single-center cohorts who had outpatient visits from November to October in 2006 to 2007 and 2007 to 2008, respectively. Generalized estimating equation analyses of repeated measures were performed for monthly NPMs.

RESULTS

The average monthly NPMs among the National Health Insurance elderly cohort was 2.33 in 2006 and 4.39 in 2007, respectively. After controlling for other factors, the increment in the proportion of monthly NPMs among the older elderly patients, in certain months and for those patients with hypertension and dyslipidemia, was statistically significant among the single-center cohort but was not observed in the national elderly cohort. The proportional changes decreased significantly among patients who made visits to emergency rooms and who were hospitalized during a 1-year period.

CONCLUSIONS

There was an incremental trend of monthly NPMs among the national cohort from 2006 to 2007. Although acute exacerbations and hospitalization might be the protecting factors of increasing monthly NPMs, more attention should be paid toward high-utilization patients with specific diseases during certain months for different elderly cohorts.

Options for treating postherpetic neuralgia in the medically complicated patient

Patients with postherpetic neuralgia (PHN) are often of advanced age or immunocompromised and likely to have ≥1 comorbid medical condition for which they receive ≥1 medication (polypharmacy). Comorbidities affecting renal or hepatic function can alter pharmacokinetics, thereby impacting the efficacy or tolerability of PHN analgesic therapies. Cardiovascular, cerebrovascular, or psychiatric comorbidities may increase patient vulnerability to potential adverse events associated with some PHN analgesic therapies. Because PHN is a localized condition, localized therapy with a topical analgesic (lidocaine patch 5% and capsaicin 8% patch or cream) may provide adequate efficacy while mitigating the risk of systemic adverse events compared with oral analgesics (eg, tricyclic antidepressants, anticonvulsants, opioids). However, combined therapy with a topical and an oral analgesic or with >1 oral analgesic may be needed for optimal pain management in some patients. This review summarizes how comorbidities and concomitant medications should be taken into account when selecting among available pharmacotherapies for PHN and provides recommendations for the selection of therapies that will provide analgesia while minimizing the risk of adverse events.

Psychopharmacology of aggression in schizophrenia

The management of aggression in patients with schizophrenia is a complex and challenging clinical dilemma. It also is greatly influenced by prevailing societal and medicolegal considerations regarding the perceived associations between violence and mental illness. This article provides a succinct account of a complex area and offers evidence for available treatments to reduce the occurrence of violent behavior among patients with schizophrenia.

Implications of opioid analgesia for medically complicated patients

Opioid analgesics have an established role in the management of postoperative pain and cancer pain, and are gaining acceptance for the management of moderate to severe chronic noncancer pain, most notably chronic low back pain and osteoarthritis, that does not respond to other interventions. Many patients with chronic pain have co-morbid medical conditions that may complicate opioid therapy. Selecting the appropriate opioid requires knowledge of how individual opioids differ with respect to metabolism and interaction with concurrent medications, as well as the reasons why specific medical conditions may influence their efficacy and tolerability. Polypharmacy is a common complicating condition in the elderly and in patients with psychiatric illness, cancer, cardiovascular disease, diabetes mellitus or other chronic illnesses. Polypharmacy, though often necessary for patients with multiple medical conditions, also multiplies the risk of drug interactions. Pharmacokinetic drug interactions can increase or reduce exposure to the opioid or concurrent medications, reducing efficacy and/or tolerability and increasing toxicity. Pharmacodynamic interactions can enhance the depressive effects of opioids, compromising safety. Patients with impaired renal or hepatic function may have difficulty clearing or metabolizing opioids and concurrent medications, leading to increased risk of adverse events. Patients with cardiovascular, cerebrovascular or respiratory disease (including smokers of >/=2 packs/day with no other diagnosis) may be more susceptible to respiratory depression, bradycardia and hypotension with any opioid, and a few specific opioids pose additional risks. Patients with cerebrovascular disease, dementia, brain injury or psychiatric illness are more susceptible to opioid effects on the CNS, which can include euphoria, cognitive impairment and sedation. Appropriate opioid selection may mitigate these effects. Even in older patients, addiction, abuse and misdirection of prescribed opioids are of concern. Higher risk exists for patients with psychiatric illness, history of substance abuse, and identifiable substance abuse risk factors. Screening for abuse potential and vigilant patient monitoring should be routine. Opioids differ in their ability to produce euphoria, based on opioid receptor agonism, but substance abusers may be more influenced by availability, familiarity and cost factors. Consequently, opioid selection has limited influence on abuse potential but can facilitate ease of monitoring. This review provides an overview of opioid use in medically complicated patients and recommendations on how to optimize analgesia while avoiding adverse events and drug interactions in the clinical setting. Articles cited in this review were identified via a search of EMBASE and PubMed. Articles selected for inclusion discussed characteristics of specific opioids and general physiological aspects of opioid therapy in important patient populations.

Polypharmacy among disabled Taiwanese elderly: a longitudinal observational study

BACKGROUND AND OBJECTIVE

It is not known whether the correlates of polypharmacy among disabled elderly are similar to those for older adults in general. Furthermore, data on polypharmacy in the Taiwanese population are limited. Therefore, this study was conducted to determine the prevalence and correlates of polypharmacy among disabled Taiwanese elderly (aged >or=65 years).

METHODS

This was a longitudinal observational study conducted on information obtained between July 2001 and June 2002. Study participants consisted of nationally representative samples of 11,788 disabled Taiwanese elderly from the ANLTCNT (Assessment of National Long-Term Care Need in Taiwan) study. Polypharmacy and major polypharmacy were defined as prescription of >or=5 and >or=10 medications, respectively, on the day of maximum numbers of prescriptions of the study year. Subject characteristics were derived from the ANLTCNT study survey data. Healthcare-related characteristics, including medication prescriptions, were obtained from the National Health Insurance (NHI) claims data. Multivariate logistic regression was performed for statistical analysis.

RESULTS

One-fifth (21.5%) of the sample were aged >or=85 years, and 58% were female. The prevalence of polypharmacy and major polypharmacy among disabled Taiwanese elderly was 81% and 38%, respectively. Nearly one-third (32.5%) of disabled Taiwanese elderly were exposed to polypharmacy for >or=181 days in 1 year. Compared with those with a low tendency for visiting multiple providers, those with intermediate tendency (odds ratio [OR] 3.61; 95% CI 3.11, 4.18) and those with high tendency (OR 10.24; 95% CI 8.56, 12.24) were more likely to be exposed to polypharmacy. Other significant correlates of polypharmacy in the multivariate logistic regression model included age <85 years, living in urban areas, higher number of chronic conditions, poorer physical functioning, preference for visiting independent clinics and not being institutionalized.

CONCLUSION

The prevalence of polypharmacy was extremely high among disabled Taiwanese elderly. Visiting multiple healthcare providers was one of the strongest correlates. Policies that encourage the disabled elderly to establish primary care relationships and that promote geriatric care models may decrease the prevalence of polypharmacy and associated adverse outcomes in this group.

Polypharmacy: misleading, but manageable

The percentage of the population described as elderly is growing, and a higher prevalence of multiple, chronic disease states must be managed concurrently. Healthcare practitioners must appropriately use medication for multiple diseases and avoid risks often associated with multiple medication use such as adverse effects, drug/drug interactions, drug/disease interactions, and inappropriate dosing. The purpose of this study is to identify a consensus definition for polypharmacy and evaluate its prevalence among elderly outpatients. The authors also sought to identify or develop a clinical tool which would assist healthcare practitioners guard against inappropriate drug therapy in elderly patients. The most commonly cited definition was a medication not matching a diagnosis. Inappropriate was part of definitions used frequently. Some definitions placed a numeric value on concurrent medications. Two common definitions (ie, 6 or more medications or a potentially inappropriate medication) were used to evaluate polypharmacy in elderly South Carolinians (n = 1027). Data analysis demonstrates that a significant percentage of this population is prescribed six or more concomitant drugs and/or uses a potentially inappropriate medication. The findings are 29.4% are prescribed 6 or more concurrent drugs, 15.7% are prescribed one or more potentially inappropriate drugs, and 9.3% meet both definitions of polypharmacy used in this study. The authors recommend use of less ambiguous terminology such as hyperpharmacotherapy or multiple medication use. A structured approach to identify and manage inappropriate polypharmacy is suggested and a clinical tool is provided.

Polypharmacy: when is it rational?

In this article, the authors discuss when it makes sense to consider using more than one medication to treat a single condition. They give a brief history of the use of polypharmacy in psychiatry and discuss how new discoveries in psychotropic drug development are making polypharmacy an increasingly important topic today. The authors then present a list of 10 criteria to guide the rational use of psychotropic polypharmacy and explain each in detail with examples drawn from clinical practice.

The potential for clinically significant drug-drug interactions involving the CYP 2D6 system: effects with fluoxetine and paroxetine versus sertraline

BACKGROUND

Patients taking antidepressants are more likely to also be taking multiple medications, increasing the risk of adverse drug-drug interactions (DDIs). Because of substantial inhibition of one or more cytochrome P450 (CYP) enzymes at therapeutic doses, the selective serotonin reuptake inhibitors fluoxetine, fluvoxamine, and paroxetine have a higher risk of CYP-mediated DDIs than citalopram, escitalopram, and sertraline, which do not substantially inhibit any CYP enzyme.

METHODS

Prescribing patterns in 2,779 Veterans Affairs (VA) patients who had a prescription for an antidepressant in the preceding year and a current prescription for at least one systemically active drug were analyzed to determine 1) prevalence of drug combinations with potential to cause CYP-mediated DDIs, 2) frequency of combinations of fluoxetine, paroxetine, or sertraline with drugs whose metabolism is principally dependent on CYP 2D6, and 3) use of reduced doses of CYP 2D6 substrate/drugs with narrow therapeutic indices in patients on fluoxetine or paroxetine compared with sertraline.

RESULTS

In 2,779 patients, 55 pairs of drugs with the potential to cause CYP-mediated DDIs occurred in 300 patients (11%), but only 26 of the patients and 6 of the drug pairs were identified by the VA Drug Alert System. Of the 461 patients receiving fluoxetine and/or paroxetine, 39 (8%) were also receiving a CYP 2D6-model substrate/drug with a narrow therapeutic index, 14 (36%) of whom were receiving high enough doses to be at moderate to high risk of a serious DDI.

CONCLUSIONS

VA patients on fluoxetine, paroxetine, and sertraline were equally likely to be on drugs whose metabolism is dependent on CYP 2D6, including drugs with narrow therapeutic indices. No differences were found in doses of tricyclic antidepressants (i.e., "victim" drugs), which have narrow therapeutic indices and serious dose-dependent toxicity, when co-prescribed with fluoxetine or paroxetine versus sertraline (i.e., "perpetrator" drugs), despite predictable differences in CYP 2D6-mediated clearance of these drugs.

Pharmacogenomics, informatics, and individual drug therapy in psychiatry: past, present and future

The modern era of psychopharmacology began in the 10 year period from the late 1940s to the late 1950s. During this period, the first antidepressants, antipsychotics, anxiolytics and mood stabilizers were all discovered. In the 1960s, the pharmacology of these drugs was elucidated and theories about the mechanisms of action proposed. In the 1970s and 1980s, new, more selective compounds were developed based on improved structure-activity relationships derived from in vitro receptor binding studies and animal models. These compounds entered clinical testing in the 1980s and began to be marketed in the late 1980s and 1990s. All of these agents were approved to treat psychiatric syndromes which are conditions defined by a cluster of signs and symptoms. None of these agents was developed based on an understanding of the pathophysiology of the illnesses being treated. None of these agents are curative and virtually all have limited clinical efficacy. In the earliest days of the modern era, there were few drugs available to combine and many had such broad actions that they were often marginally tolerated or unsafe when used in combination (tricyclic antidepressants and monoamine oxidase inhibitors). With the advent of more medications, the frequency and extent of polypharmacy has exploded. In addition to simply having more drugs from which to select with different pharmacological profiles, many newer medications are also more selective in their pharmacological actions and thus are often better tolerated and safer when used in combination. In addition, there is the concern that the trade-off for more selective pharmacology may have been better tolerability at the expense of reduced efficacy, which clinicians then compensate for by using more medications in combination. For all of the above reasons, polypsychopharmacology has been present from the beginning of the modern era of psychopharmacotherapy and continues to be the rule rather than the exception. In fact, the frequency and the complexity of such polypsychopharmacology are both enormous and increasing. The percentage of patients being discharged from the Biological Branch of the National Institute of Mental Health on more than three psychiatric medications increased more than ten times between 1974-79, and 1990-95. The majority of patients seen in the Veterans Administration Medical System in the United States are on unique combinations of medications and the frequency and complexity of such polypharmacotherapy is increased in patients on psychiatric medications. Throughout the modern era, there have been attempts to determine whether there are populations of patients selectively responsible to specific agents (e.g. serotonin versus norepinephrine reuptake inhibitors). However, no compelling data have so far emerged. Instead, clinicians generally resort to combining drugs on the basis of symptoms such as psychosis and depression or anxiety and depression. Science has primarily informed the clinician about safety concerns rather than efficacy concerns when using such combinations. That will change in the future with a better understanding of the pathophysiology of psychiatric illnesses which in turn will lead to improved therapies and the potential for more rationally derived combination treatments.

Complexity of medication use in the Veterans Affairs healthcare system: Part II. Antidepressant use among younger and older outpatients

CONTEXT

A previous study, described in Part I of this report, found that 71% of a sample of 5,003 general outpatients in the Veterans Affairs healthcare system were receiving a unique drug regimen (i.e., total specific drug entities regardless of dose, formulation, or administration schedule). The simplest regimens contained only one drug, while the most complex regimens exceeded 20 different drugs. The purpose of the present study was to determine if patients receiving a specific therapeutic class of medications (e.g., antidepressants) have more homogeneous drug regimens.

OBJECTIVE

to examine the extent and complexity of multiple medication use in younger and older adult outpatients receiving antidepressants compared with those not receiving antidepressants. The study focused on drugs that act systemically or gastrointestinally and hence have the potential to interact.

DESIGN, SETTING, AND PARTICIPANTS

Two subsets of stratified random samples of outpatients selected from prescription databases of U.S. Veterans Integrated Service Network 15. The first group involved 1,991 patients deemed to be on antidepressants (AD patients): 891 aged < 60 years and 1,100 aged > or = 60 years. The second group involved 3,732 patients who had received no antidepressants within the previous 365 days but who had a supply of at least one other current prescription (NoAD patients): 1,195 aged < 60 years and 2,535 aged > or = 60 years; 2 missing age information.

MAIN OUTCOME MEASURES

number of drugs, frequency of drug regimens, level of multiple medication use including and excluding antidepressants.

RESULTS

Younger AD patients received 3 more drugs than younger NoAD patients. 23.6% of younger AD patients, versus 5.9% of younger NoAD patients, received > or = 8 drugs. Older AD patients received 2 more drugs than older NoAD patients. 37.6% of older AD patients, versus 12.8% of older NoAD patients, received > or = 8 drugs. In both the AD and NoAD groups, 62%-96% of patients of all ages were receiving unique drug regimens. Each drug regimen containing 2 or more drugs occurred in fewer than 1% of patients.

CONCLUSIONS

AD patients were receiving more complex drug regimens and had a higher frequency of unique drug regimens than NoAD patients, even when the results were adjusted for age group and number of prescribers. The high prevalence of unique drug combinations in all patient groups in this study indicates that clinicians in this system have only limited experience with the total effects of all of the medications their patients are receiving and thus cannot rely on experience to guard against adverse multi-drug interactions. This fact is a particular concern with psychiatric medications because adverse DDIs involving these medications can mimic psychiatric symptoms and may therefore be more difficult to detect.