Prescription of contraindicated and interacting drugs in elderly patients admitted to hospital

Evaluation of Potential Drug Interactions with AiDKlinik® in a Random Population Sample

Purpose

Undesirable drug interactions are frequent, they endanger the success of therapy, and they lead to adverse drug reactions. The present study aimed to evaluate statistically potentially drug interactions in a locally circumscribed, random sample population.

Patients and Methods

In a random sample population of 264 patients taking medications, we performed analyses with the drug information system AiDKlinik^®. Statistical analysis was performed using SAS version 9.4.

Results

Statistically potentially drug interactions were recorded in 82/264 (31.1%) subjects, including 39/82 (47.56%) men, and 43/82 (52.43%) women (χ²= 0.081; p = 0.776). The average number of potential possible interactions detected per person was 1.60 ± 1.21. The regression model with the variables age, body-mass-index and number of long-term-medications shows a significant association between the number of long-term medications taken and the number of moderately severe and severe reactions to drug interactions (F(3.239) = 28.67, p < 0.0001; (t(239) 8.28; p < 0.0001)). After backward elimination, the regression model showed a significant interaction with the number of long-term medications (t (240) = 8.73, p < 0.0001) and body-mass-index (t (240) = 2.02, p = 0.0442). In descriptive analysis, the highest percentages of potential drug interactions occurred in 42/82 (51.22%) subjects with body mass indices (BMIs) >25 kg/m² and in 28/82 (34.15%) subjects aged 61–70 years.

Conclusion

Number of long-term medications use, age, and obesity may lead to increased drug–drug interactions in a random population sample.

Are drug-drug interactions a real clinical concern?

Aim:

Although drug-drug interactions (DDIs) cause major adverse drug reactions (ADRs) in patients under polypharmacy, the risk of some specific DDIs may be overrated in literature and different software. This study was conducted to determine the frequency and type of potential and clinically significant DDIs among inpatients admitted in a tertiary care hospital in South India.

Materials and Methods:

This longitudinal study was conducted for 30 days. Preformatted forms were used to collect data on the second day of admission. “Medscape Drug Interaction Checker” was used to evaluate and grade the DDIs. All the potential serious DDIs were intimated to the treating physicians and their responses in the prescriptions were noted. The same patients were followed up to evaluate the occurrence of any clinically significant DDIs.

Results:

A total of 763 drugs with 125 discrete types were prescribed in 155 patients with an average of 4.9 drugs per patient. One hundred and eight minor, 169 significant, and 24 serious potential DDIs were identified. Patient's age did not correlate, but number of drugs prescribed strongly correlated (P < 0.001) with the incidence of different types of DDIs. The prescription was modified in only 6 (25%) cases where potential serious DDIs were reported. Interestingly, no ADRs or impaired efficacy was observed due to the potential serious DDIs.

Conclusion:

There was a disparity between the potential and clinically relevant DDIs. Hence, clinical prudency is required before changing prescription due to potential DDIs reported by different software.

Potential drug-drug interactions among prescriptionsfor elderly patients in primary health care

BACKGROUND/AIM

Elderly patients are at high risk from drug-drug interactions (DDIs). This study evaluates the potential DDIs in Turkish elderly patients at a primary health care outpatient clinic.

MATERIALS AND METHODS

Online database systems were used to examine DDIs on the prescriptions of patients (n = 1206). The clinical severity of DDIs was classified by the Lexi-Interact Online database.

RESULTS

Of the 5059 prescriptions, 33% were found to have DDIs. We detected 29 (0.9%) A, 380 (11.8%) B, 2494 (77.7%) C, 289 (9%) D, and 18 (0.6%) X risk rating category DDIs among the prescriptions. Prescriptions of female patients and patients aged between 65 and 72 years showed significantly higher number of DDIs. The frequency of DDIs increased both with the number of drugs and combined preparations per prescription. Acetylsalicylic acid and salbutamol were the most frequently prescribed drugs contributing to clinically important DDIs. Additionally, acetylsalicylic acid and escitalopram, which interact with each other, were found on the list of Beers criteria. The most predicted clinical outcomes of DDIs were increase in therapeutic efficacy and adverse/toxic reactions. Conclusions: Prediction of DDIs in elderly patients will provide better prescribing and drug safety. Use of nonsteroidal anti-inflammatory agents, selective serotonin reuptake inhibitors, and beta-2 adrenergic receptor agonists should be closely monitored.

Potential drug-drug and drug-disease interactions in well-functioning community-dwelling older adults

WHAT IS KNOWN AND OBJECTIVE

There are few studies examining both drug-drug and drug-disease interactions in older adults. Therefore, the objective of this study was to describe the prevalence of potential drug-drug and drug-disease interactions and associated factors in community-dwelling older adults.

METHODS

This cross-sectional study included 3055 adults aged 70-79 without mobility limitations at their baseline visit in the Health Aging and Body Composition Study conducted in the communities of Pittsburgh PA and Memphis TN, USA. The outcome factors were potential drug-drug and drug-disease interactions as per the application of explicit criteria drawn from a number of sources to self-reported prescription and non-prescription medication use.

RESULTS

Over one-third of participants had at least one type of interaction. Approximately one quarter (25·1%) had evidence of had one or more drug-drug interactions. Nearly 10·7% of the participants had a drug-drug interaction that involved a non-prescription medication. % The most common drug-drug interaction was non-steroidal anti-inflammatory drugs (NSAIDs) affecting antihypertensives. Additionally, 16·0% had a potential drug-disease interaction with 3·7% participants having one involving non-prescription medications. The most common drug-disease interaction was aspirin/NSAID use in those with history of peptic ulcer disease without gastroprotection. Over one-third (34·0%) had at least one type of drug interaction. Each prescription medication increased the odds of having at least one type of drug interaction by 35-40% [drug-drug interaction adjusted odds ratio (AOR) = 1·35, 95% confidence interval (CI) = 1·27-1·42; drug-disease interaction AOR = 1·30; CI = 1·21-1·40; and both AOR = 1·45; CI = 1·34-1·57]. A prior hospitalization increased the odds of having at least one type of drug interaction by 49-84% compared with those not hospitalized (drug-drug interaction AOR = 1·49, 95% CI = 1·11-2·01; drug-disease interaction AOR = 1·69, CI = 1·15-2·49; and both AOR = 1·84, CI = 1·20-2·84).

WHAT IS NEW AND CONCLUSION

Drug interactions are common among community-dwelling older adults and are associated with the number of medications and hospitalization in the previous year. Longitudinal studies are needed to evaluate the impact of drug interactions on health-related outcomes.

Potential drug-drug interactions in a medical intensive care unit of a university hospital

BACKGROUND/AIM

Drug-drug interactions (DDIs) can impact patient safety. Occurrence of clinically important DDIs is higher for intensive care unit (ICU) patients. This observational study aimed to evaluate the potential DDIs in medical ICU patients of a university hospital.

MATERIALS AND METHODS

The Medical Pharmacology Department organized consultation reports for ICU patients in order to detect the DDIs. To focus on clinically important DDIs, interactions in the C, D, or X risk rating categories of the Lexi-Interact online database were analyzed. Frequency and clinical risk rating categories of DDIs were detected. Relationship between number of prescriptions and DDIs were assessed. The most frequent drug/drug groups were identified.

RESULTS

Of 101 ICU patients, 45.5% were found to have DDIs. We detected 125 C (72.2%), 37 D (21.4%), and 11 X (6.4%) risk category interactions. A statistically significant increase in the number of DDIs was shown with the number of prescriptions (P = 0.002). The most frequent DDIs were between agents acting on the cardiovascular system and corticosteroids (12.8%).

CONCLUSION

Results of this study show that pharmacological consultation plays a critical role in the recognition of DDIs for improvement of medication management and effective therapeutic endpoints without any adverse or toxic reactions.

A Study on Polypharmacy and Potential Drug-Drug Interactions among Elderly Patients Admitted in Department of Medicine of a Tertiary Care Hospital in Puducherry

INTRODUCTION

The proportion of elderly population has been constantly increasing over last few years. Polypharmacy is unavoidable in the elderly as they often suffer from multiple co-morbidities. Potential drug-drug interaction due to polypharmacy and potential inappropriate medication among the elderly must be carefully assessed.

AIM

To find out polypharmacy and potential drug-drug interactions among elderly patients admitted and discharged in Department of Medicine.

MATERIALS AND METHODS

This study was carried out on 100 patients above 65 years of age both males and females. Data was collected through review of case sheets. Polypharmacy was observed based on admission and discharge prescriptions. Frequently occurring drug-drug interactions were assessed using online checks.

RESULTS

Mean number of drugs prescribed to patients on admission (7.61 ± 3.37) was more than that on discharge (5.48±2.46). More than half of these patients received 5 to 9 number of drugs. On admission 52.69% potential drug-drug interactions were observed and on discharge 52.91%. Most common drug interactions observed in both the groups were of moderate grade.

CONCLUSION

From the present study we can conclude that polypharmacy leads to more potential drug-drug interactions. To improve drug safety in this high-risk population, appropriate prescribing is very important.

Appropriate prescribing in the elderly: Current perspectives

Advances in medical therapeutics have undoubtedly contributed to health gains and increases in life expectancy over the last century. However, there is growing evidence to suggest that therapeutic decisions in older patients are frequently suboptimal or potentially inappropriate and often result in negative outcomes such as adverse drug events, hospitalisation and increased healthcare resource utilisation. Several factors influence the appropriateness of medication selection in older patients including age-related changes in pharmacokinetics and pharmacodynamics, high numbers of concurrent medications, functional status and burden of co-morbid illness. With ever-increasing therapeutic options, escalating proportions of older patients worldwide, and varying degrees of prescriber education in geriatric pharmacotherapy, strategies to assist physicians in choosing appropriate pharmacotherapy for older patients may be helpful. In this paper, we describe important age-related pharmacological changes as well as the principal domains of prescribing appropriateness in older people. We highlight common examples of drug-drug and drug-disease interactions in older people. We present a clinical case in which the appropriateness of prescription medications is reviewed and corrective strategies suggested. We also discuss various approaches to optimising prescribing appropriateness in this population including the use of explicit and implicit prescribing appropriateness criteria, comprehensive geriatric assessment, clinical pharmacist review, prescriber education and computerized decision support tools.

Evaluation of potential drug - drug interactions in general medicine ward of teaching hospital in southern India

BACKGROUND

Polypharmacy is considered as one of the major risk factors in precipitation of drug-drug interactions (DDIs). Patient population at high risk include the elderly and patients with co morbidities as they are usually prescribed with more number of drugs. Critical evaluation of such prescriptions by pharmacist could result in identification and reduction of such problems.

OBJECTIVE

The study aims to assess the prevalence, severity and significance of potential DDI (pDDI) in general medicine wards of South Indian tertiary care teaching hospital.

MATERIALS AND METHOD

A prospective observational study was conducted in a general medicine ward for a period of six months (September 2012 to February 2013). The socio-demographic, clinical characteristics and medication prescribed was documented in a specially designed form. Analysis was carried out to assess the prevalence, severity and significance of identified pDDIs using Micromedex. Descriptive and Univariate analysis were used to report the findings.

RESULTS

A total of 404 case records reviewed, 78 (19.3%) patients had pDDIs. A total of 139 (34.4%) pDDIs were reported during the study period. Majority (53.95%, n=75) of the interactions were moderate in intensity and significant in nature (53.23%, n=74). Positive association between number of pDDIs and age was observed.

CONCLUSION

The prevalence of pDDIs was 19.3% which is lesser then previously reported studies from India. Patient with more co-morbidities and elders were observed with more pDDIs. The study highlighted the need to effectively monitor and patients prevent pDDIs to improve patient safety.

A pharmacovigilance study in the department of medicine of a university teaching hospital

The aim of the present study was to monitor adverse drug reactions (ADRs) in the Medicine out patient department (OPD) of a University Teaching Hospital.

A study on drug-drug interactions through prescription analysis in a South Indian teaching hospital

OBJECTIVE

The objective of this study was to assess the drug-drug interactions (DDIs) through prescription analysis among the inpatients of a South Indian teaching hospital.

METHODS

The study was a prospective observational prescription analysis conducted for a period of 6 months, from October 2010 to March 2011. The prescriptions having two or more drugs and where a DDI was suspected were selected by the physician in charge of the ward. The drugs in the prescription were then entered into the drug interaction checker software. The DDIs were classified based on the mechanism of interactions, severity of interactions, relation to the number of drugs prescribed, and disease conditions were also determined.

RESULTS

A total of 204 prescriptions were analyzed, of which 186 prescriptions had 856 DDIs. Most of the DDIs were pharmacokinetic drug interactions (42%) followed by unknown mechanisms (34%) and pharmacodynamic mechanisms (24%). The study findings showed that the prescriptions for cardiovascular with respiratory disease conditions had the greatest number of drug interactions on average. A severity assessment showed that majority of the DDIs were moderate (70%) followed by minor (28%). The study results showed that as the number of drugs increases in a prescription, the number of DDIs also increases. The interventions determined showed that dosage adjustment (12%) was to be followed in most of the DDIs.

CONCLUSION

This study assists in understanding the factors associated with DDIs that can help in safe and effective use of drugs in the future.

Prescription peer academic detailing to reduce inappropriate prescribing for older patients: a cluster randomised controlled trial

BACKGROUND

Older patients are at particular risk for adverse drug reactions. In older people, interventions targeting potentially inappropriate prescriptions (PIPs) are considered important measures to minimise drug-related harm, especially in the general practice setting where most prescriptions for older patients are issued.

AIM

To study the effects of a multifaceted educational intervention on GPs' PIPs for older patients.

DESIGN AND SETTING

This was a cluster randomised, educational intervention study in Norwegian general practice. Pre-study data were captured from January 2005 to December 2005 and post-study data from June 2006 to June 2007. The educational intervention was carried out from January 2006 to June 2006.

METHOD

Eighty continuing medical education (CME) groups (465 GPs) were randomised to receive the educational intervention on GPs' PIPs for older patients (41 CME groups; 256 GPs) or another educational intervention (39 CME groups; 209 GPs); these two groups acted as controls for each other. GPs' prescription data from before and after the intervention were assessed against a list of 13 explicit PIP criteria for patients aged ≥70 years. In the CME groups, trained GPs carried out an educational programme, including an audit, focusing on the 13 criteria and their rationale.

RESULTS

A total of 449 GPs (96.6%) completed the study; 250 in the intervention group and 199 in the control group. After adjusting for baseline differences and clustering effects, a reduction relative to baseline of 10.3% (95% confidence interval = 5.9 to 15.0) PIPs per 100 patients aged ≥70 years was obtained.

CONCLUSION

Educational outreach visits with feedback and audit, using GPs as academic detailers in GPs' CME groups, reduced PIPs for older patients aged ≥70 years in general practice.

Prescribing in care homes: the role of the geriatrician

Large numbers of frail elderly people spend some time of their lives in care homes. Increasing age is associated with altered physiology, multiple diagnoses and complex comorbidity, and polypharmacy. Those living in care homes often take larger numbers of medications than those who live in the community and the risk of morbidity as a direct or indirect result of medications is high. Many methods have been suggested to revise the number and type of medications prescribed for individuals at risk of adverse drug reactions (ADRs), both in the community and in hospital with variable success and implementation. Assessment of prescribed and nonprescribed medications by pharmacists, nurses and general practitioners all have a role in optimizing therapeutics with evidence that improved prescribing can reduce the risk of ADRs. In conjunction with these professionals, community geriatricians undertaking a comprehensive geriatric assessment can reduce the number of medications prescribed or optimize therapy where there may be underprescribing (e.g. in depression), thereby reducing the overall risk of hospital admission ADRs.

Adverse drug reactions caused by drug-drug interactions reported to Croatian Agency for Medicinal Products and Medical Devices: a retrospective observational study

Aim

To analyze potential and actual drug-drug interactions reported to the Spontaneous Reporting Database of the Croatian Agency for Medicinal Products and Medical Devices (HALMED) and determine their incidence.

Methods

In this retrospective observational study performed from March 2005 to December 2008, we detected potential and actual drug-drug interactions using interaction programs and analyzed them.

Results

HALMED received 1209 reports involving at least two drugs. There were 468 (38.7%) reports on potential drug-drug interactions, 94 of which (7.8% of total reports) were actual drug-drug interactions. Among actual drug-drug interaction reports, the proportion of serious adverse drug reactions (53 out of 94) and the number of drugs (n = 4) was significantly higher (P < 0.001) than among the remaining reports (580 out of 1982; n = 2, respectively). Actual drug-drug interactions most frequently involved nervous system agents (34.0%), and interactions caused by antiplatelet, anticoagulant, and non-steroidal anti-inflammatory drugs were in most cases serious. In only 12 out of 94 reports, actual drug-drug interactions were recognized by the reporter.

Conclusion

The study confirmed that the Spontaneous Reporting Database was a valuable resource for detecting actual drug-drug interactions. Also, it identified drugs leading to serious adverse drug reactions and deaths, thus indicating the areas which should be in the focus of health care education.

Identifying prediction factors for unplanned hospitalisation of an elderly population using classification and regression tree (CART) analysis

Accurate prediction of those elderly people who are at a high risk of unplanned hospitalisation may assist pharmacists and other health care providers to target health care initiatives more specifically. A prospective study of 84 elderly persons, suffering from either ischaemic heart disease or obstructive airways disease, or both, was conducted to identify health-related factors that may be used to predict unplanned hospitalisation. Non-invasive factors, including the sickness impact profile (SIP) health status measure scores, drug consumption, demographic data, smoking history and disease/symptoms experience were determined. For hospitalised patients the overall SIP score was significantly higher (18.93) than for those non-hospitalised (10.54). The physical dimension score (20.76) and the psychosocial dimension score (16.74) were also both significantly higher in the hospitalised than the non-hospitalised group (10.85 and 9.44, respectively). The number of medicines used was higher (8.2) in the hospitalised group than in the non-hospitalised group (6.3). Logistic regression determined that the overall SIP score was highly predictive (P&lt;0.01) of unplanned hospitalisation. Classification and regression tree (CART) analysis was used to determine the mix of health-related factors that could best classify subjects as being at either a high or low risk for unplanned hospitalisation within the six month prospective study period. A selected CART-generated decision protocol determined that the health-related parameters that enabled a useful prediction for unplanned hospitalisation were overall SIP score, the person's age, whether the person lived alone and smoking history. Seventy-nine per cent of those hospitalised and 91 per cent of those non-hospitalised had been correctly predicted. The results of this study show that it is possible to predict unplanned hospitalisation of elderly people in a retirement village setting by using previously measured non-invasive health related parameters in a decision protocol to determine their category of risk.

Drugs prescribed for people aged 85 and over living in their own homes in an area of inner London

This study investigated drugs prescribed for people aged 85 and over and living in their own homes in an area of inner London, and explored associations between drug use and other factors including use of general medical practitioner (GP) services, mobility, mortality and self-perceived health. Data were collected by structured interview of 630 participants in their own homes, with a follow-up interview of survivors three years later.

Respondents were taking a mean of 2.2 different drugs; 23 per cent were taking no prescribed drugs and 11 per cent were taking five or more. Of those on two or more drugs, 45 per cent were taking potentially interacting combinations. Although respondents on more drugs were more likely to have seen their GP recently, some on many different drugs had not. Nearly 15 per cent reported some sort of difficulty with their medication.

There was no significant difference between the mean number of drugs prescribed, at the begining of the study, for survivors and for non-survivors. However, there was an inverse relationship between prescribed medication and mobility, self-perceived health and satisfaction with other aspects of life. Very elderly people living in their own homes, like those in institutions, will frequently be on drug regimens that should be monitored regularly for drug-related problems. Because of rising numbers, the provision of a cost-effective service would require the identification of those most likely to experience problems with their medication.

Potential drug interactions in patients admitted to cardiology wards of a south Indian teaching hospital

BACKGROUND

The potential drug-drug interaction (pDDI) increases as the number of concomitant medications increases. Patients with cardiovascular disorders are at higher risk for drug- drug interactions because of the types and number of drugs they receive. While drug interactions are reported to be common, there is no published report of the prevalence of such interactions among Indian cardiac patients. The aim of the present study was to identify the pattern of pDDI and document any observed interaction. It was also planned to evaluate the demography of patients and correlate it with the drug-drug interactions.

METHOD

A prospective observational study from Oct 2007 to Apr 2008 was carried out in 'cardiology department' of a hospital in South India. Those patients who were taking at least two drugs and had a hospital stay of at least 48 hours were included in the study. The medications of the patients were analyzed for possible interactions. Factors associated with pDDI were studied. The actual interactions that were observed during the hospital stay in the study subjects were documented.

RESULTS

A total of 812 patients were included in the study. 388 pDDIs were identified among 249 patients. The incidence of pDDI was 30.67%. The most common potential interactions were between aspirin & heparin (29.38%), and clopidogrel & heparin (7.21%). Drug classes most commonly involved were antiplatelets, anticoagulants and diuretics. Majority of interactions were of moderate severity, delayed onset, and pharmacodynamic in nature. Total 68 actual interactions were observed in the observed cases.

CONCLUSION

The present study identified pDDIs and also documented interactions in cardiovascular patients. Factors which had correlation with adverse drug interactions were identified. This study highlights the need for screening prescriptions of cardiovascular patients for pDDIs and proactive monitoring of patients who have identified risk factors; this helps in detection and prevention of possible adverse drug interactions.

Potentially inappropriate medication utilization in the emergency department visits by older adults: analysis from a nationally representative sample

OBJECTIVES

The objectives were to determine the frequency of administration of potentially inappropriate medications (PIMs) to older emergency department (ED) patients and to examine recent trends in the rates of PIM usage.

METHODS

The data examined during the study were obtained from the National Hospital Ambulatory Medical Care Survey (NHAMCS). This study utilized the nationally representative ED data from 2000-2006 NHAMCS surveys. Our sample included older adults (age 65 years and greater) who were treated in the ED and discharged home. Estimated frequencies of PIM-associated ED visits were calculated. A multivariable logistic regression model was created to assess demographic, clinical, and hospital factors associated with PIM administration and to assess temporal trends.

RESULTS

Approximately 19.5 million patients, or 16.8% (95% confidence interval [CI]=16.1% to 17.4%) of eligible ED visits, were associated with one or more PIMs. The five most common PIMs were promethazine, ketorolac, propoxyphene, meperidine, and diphenhydramine. The total number of medications prescribed or administered during the ED visit was most strongly associated with PIM use. Other covariates associated with PIM use included rural location outside of the Northeast, being seen by a staff physician only (and not by a resident or intern), presenting with an injury, and the combination of female sex and age 65-74 years. There was a small but significant decrease in the proportion of visits associated with a PIM over the study period.

CONCLUSIONS

Potentially inappropriate medication administration in the ED remains common. Given rising concerns about preventable complications of medical care, this area may be of high priority for intervention. Substantial regional and hospital type (teaching versus nonteaching) variability appears to exist.

A pharmacovigilance study in medicine department of tertiary care hospital in chhattisgarh (jagdalpur), India

The aim of the present study was to observe adverse drug reactions (ADRs) with respect to polypharmacy at tertiary care centre at Bastar, Jagdalpur (Government Medical College, Jagdalpur). A prospective, observational evaluation of the ADRs conducted over a period of 6 months in Department of Medicine in Government Medical College, Jagdalpur. During the study period, a total of about 4850 patients visited the OPD and inpatient ward of medicine department, and 154 ADRs events were reported. Out of 154 reports that were identified, a higher percentage of ADRs in females (51.29%) was observed as compared to males (48.7%). Of the 154 ADRs, 76 (49.35%) were found to be mild, 55 moderate (35.71%), and 23 severe (14.93%). A total of 99 (64.28%) ADRs were observed in patients receiving four or more medications concurrently. Conversely 55 (35.71%) ADRs were detected in patients using three or less medicines. The largest number of reports was associated with antimicrobial therapy (28.57%), followed by antihypertensive (24.02%) and antidiabetics (14.28%). Among the affected organ systems, gastrointestinal ADRs constituted a major component (39.61%) followed by skin reactions (28.57%). On causality assessment, nearly 36.36% ADRs were considered as probable, 31.16% possible, and 9.74% could not be categorized and were placed under unassessable. Expected, limited ADR are permissible in normal clinical setting, but the present study focuses on the result showing increased and amplified ADR associated with the polypharmacy practices, which may be curtailed with rational drug prescribing habit.

Reduction of suboptimal prescribing and clinical outcome for dementia patients in a senior behavioral health inpatient unit

BACKGROUND

Suboptimal prescribing in older psychiatric patients causes iatrogenic morbidity. The objectives of this study were to compare the prevalence of suboptimal prescribing before and after admission to a geropsychiatry inpatient unit and to evaluate a possible correlation between optimal medication use and functional improvement in patients with dementia.

METHODS

The study sample comprised 118 consecutively admitted patients to a 14-bed university hospital-based geropsychiatry inpatient unit over a period of 20 months who met the DSM-IVTR criteria for an Axis I psychiatric illness and co-morbid dementia. At admission demographic information, Mini-mental State Examination (MMSE) Score, Mattis Dementia Rating Scale Score (DRS), and number of active medical illnesses were recorded. At admission and discharge the number and type of medications, number of Revised Beers Criteria (RBC) medications (a published list of potentially inappropriate medications in older adults independent of diagnoses or conditions), Global Assessment of Functioning (GAF) scores, and Scale of Functioning (SOF) scores were tabulated. chi2 tests, paired t-tests and Pearson correlations were used to test the medication prevalence and associations between measures of clinical function and other variables.

RESULTS

The mean age (standard deviation) of the sample was 81.5 (6.2) years. The mean scores on the MMSE and DRS were 22.1 (6.2) and 116.6 (18.7), respectively. From admission to discharge, the mean number of RBC medications per patient decreased significantly from 0.8 (1.1) to 0.4 (0.6). There was also a significant correlation between reduction in Beers criteria medications and improved SOF score from time of admission to time of discharge.

CONCLUSION

Suboptimal medication use is a potential source of decreased function in older patients with dementia.

Prevalence of drug-drug interactions at hospital entry and during hospital stay of patients in internal medicine

OBJECTIVE

The aim of this study was to assess potential drug-drug interactions (pDDIs) at hospital admission, during hospitalization and at discharge and to evaluate the number of pDDIs created during hospitalization.

METHODS

The medication of 851 patients was screened for pDDIs (major and moderate severity) using the screening program Pharmavista. The frequency of pDDIs per patient, per number of drugs and drug pairs was estimated.

RESULTS

During hospitalization, the frequency of major and moderate pDDIs per patient was 1.11, which was higher compared to hospital admission (0.59) or to hospital discharge (0.60). The frequency of major and moderate pDDIs per drug prescribed (13.7% vs. 9.1%) or per drug pairs analyzed (4.5% vs. 2.3%) was higher at hospital admission compared to hospital discharge. 47% of all major and moderate pDDIs at discharge were due to a medication change during hospitalization.

CONCLUSIONS

Although the number of major and moderate pDDIs per patient did not increase from hospital admission to discharge, it is important to realize that 47% of all major and moderate DDIs at hospital discharge were created during hospitalization. Prescribing drugs with a low risk for pDDIs as well as careful monitoring for adverse drug reactions are important measures to minimize harm associated with DDIs.

Contribution of the geriatrician to the management of cancer in older patients

With an increasingly aged population, many patients will present with cancer in their 80s and 90s. Although some may be very fit, frail individuals will require the input of geriatricians to aid in the assessment of co-existing morbidity, in an attempt to assess those most likely to benefit from active treatment of their cancer, and those in whom the 'giants of geriatric medicine' require special consideration before undergoing definitive cancer therapy. The role of the geriatrician in assessment and management of such patients, together with communication and end of life care, may be more important in ensuring a good quality of life, than the cancer therapy itself. Whilst numbers of geriatricians will not be adequate to care for all elderly patients with cancer, a variety of assessment scales will help target financial and manpower resources to those most at risk.

Appropriate prescribing in elderly people: how well can it be measured and optimised?

Prescription of medicines is a fundamental component of the care of elderly people, and optimisation of drug prescribing for this group of patients has become an important public-health issue worldwide. Several characteristics of ageing and geriatric medicine affect medication prescribing for elderly people and render the selection of appropriate pharmacotherapy a challenging and complex process. In the first paper in this series we aim to define and categorise appropriate prescribing in elderly people, critically review the instruments that are available to measure it and discuss their predictive validity, critically review recent randomised controlled intervention studies that assessed the effect of optimisation strategies on the appropriateness of prescribing in elderly people, and suggest directions for future research and practice.

Inappropriate medication use in elderly lebanese outpatients: prevalence and risk factors

BACKGROUND

Inappropriate use of medications has become an international cause for concern in geriatric patients, who are at high risk of drug-related morbidity. This study is the first attempt to determine the prevalence of inappropriate drug use in elderly Lebanese outpatients, using community pharmacy data, and to identify factors that predict potentially inappropriate drug intake in this population.

METHODS

Records of elderly patients aged > or =65 years were selected from different community pharmacies. Each patient profile was reviewed and to confirm patient record information, in-person interviews were conducted with elderly patients between November 2004 and May 2005 by qualified pharmacists. Based on a literature review describing guidelines for the inappropriate use of medications in the elderly, courses of therapy were assessed and classified as either appropriate or inappropriate. Courses of therapy that were judged inappropriate were further classified according to the specific area of inappropriate use (i.e. Beers' criteria, duplicate therapy, indication, dose, dose frequency including missing doses, duration and discontinuation of therapy, adverse effects, drug-drug and/or drug-disease interactions, and poor memory). Statistical analyses were performed to estimate the prevalence of inappropriate medication use and to identify potentially predictive factors of such use arising from patients' sociodemographic characteristics, health factors and drug regimen intake.

RESULTS

A total of 350 elderly patient profiles were reviewed, from which 277 evaluable records were obtained. More than half (59.6%) of the patients taking drugs at the time of the study were taking at least one inappropriate medication. Inappropriate medication use was most frequently identified in terms of Beers' criteria (22.4%), missing doses (18.8%) or incorrect frequency of administration of drugs (13.0%). Factors predicting potentially inappropriate drug intake included female sex (65.7% vs 53.3% for males, p = 0.03) and alcohol intake (p = 0.007). There were also significant associations between the likelihood of use of an inappropriate drug and (i) increased number of medical illnesses (p < 0.00002); and (ii) consumption of an over-the-counter drug (OTC) and/or prescription drug (p = 0.048 and p = 0.0035, respectively). The likelihood of use of an inappropriate drug was higher again when patients concurrently used both OTC and prescription drugs (p < 0.0002).

CONCLUSION

The present study is the first to describe and assess inappropriate medication use by elderly outpatients in the Lebanese community setting. With increasing availability of newer and more appropriate medications, use of potentially inappropriate drugs may decrease. Pharmacists have a major role to play in counselling patients about the importance of appropriate drug use.

Clinically important drug-disease interactions and their prevalence in older adults

BACKGROUND

Older adults may have decreased homeostatic reserve, have multiple chronic diseases, and take multiple medications. Therefore, they are at risk for adverse outcomes after receiving a drug that exacerbates a chronic disease.

OBJECTIVES

The aims of this study were to compile a list of clinically important drug-disease interactions in older adults, obtain the consensus of a multidisciplinary panel of geriatric health care professionals on these interactions, and determine the prevalence of these interactions in a sample of outpatients.

METHODS

This analysis included a 2-round modified Delphi survey and cross-sectional study. Possible drug-disease interactions in patients aged > or =65 years were identified through a search of the English-language literature indexed on MEDLINE and International Pharmaceutical Abstracts (1966-July 2004) using terms that included drug-disease interaction, medication errors, and inappropriate prescribing. Nine health care professionals with expertise in geriatrics (2 geriatricians, 7 geriatric clinical pharmacist specialists) were selected based on specialty training and continuing clinical work in geriatrics, academic appointments, and geographic location. The panel rated the importance of the potential drug-disease interactions using a 5-point Likert scale (from 1 = definitely not serious to 5 = definitely serious). Consensus on a drug-disease interaction was defined as a lower bound of the 95% CI > or =4.0. The prevalence of drug-disease interactions was determined by applying the consensus criteria to a convenience sample of frail older veterans at hospital discharge who were enrolled in a health services intervention trial.

RESULTS

The panel reached consensus on 28 individual drug-disease interactions involving 14 diseases or conditions. Overall, 205 (15.3%) of the 1340 veterans in the sample had > or =1 drug-disease interaction. The 2 most common drug-disease interactions were use of first-generation calcium channel blockers in patients with congestive heart failure and use of aspirin in patients with peptic ulcer disease (both, 3.7%).

CONCLUSIONS

A survey of multidisciplinary geriatric health care professionals resulted in a concise consensus list of clinically important drug-disease interactions in older adults. Further research is needed to examine the impact of these drug-disease interactions on health outcomes and their applicability as national measures for the prevention of drug-related problems.

A pharmacoepidemiologic study of drug interactions in a Brazilian teaching hospital

PURPOSE

Although drug-drug interactions constitute only a small proportion of adverse drug reactions, they are often predictable and therefore avoidable or manageable. There are few studies on drug-drug interactions from Brazil. This study aimed to assess the frequency of drug-drug interactions in prescriptions and their potential clinical significance in patients of a Brazilian teaching hospital.

METHODS

From January to April 2004, a sample of 1785 drug prescriptions was drawn from a total of 11,250. Drug-drug interactions were identified by using Micromedex DrugReax System. Patients'records with major drug-drug interactions were reviewed by a pharmacist and a medical doctor looking for signs, symptoms, and lab tests that could indicate adverse drug reactions due to such interactions.

RESULTS

From the 1785 prescriptions examined, 1089 (61%) were from the male adult ward. Patients' average age was 52.7 years (SD = 18.9; range, 12-98). The median number of drugs in each prescription was 7 (range, 2-26). At least 1 drug-drug interactions was present in 887 (49.7%) prescriptions. Regarding the severity of the clinical result, the interactions were classified as minor (20; 2.3%), moderate (184; 20.7%), major (30; 3.4%), and undetermined because of an incidence of more than 1 interaction in a single patient (653; 73.6%). From the 30 patients with major interactions, 17 (56.7%) presented adverse drug reactions induced by exposure to a major drug-drug interaction.

CONCLUSIONS

Patients did suffer adverse drug reactions from major drug-drug interactions. Many physicians may be unaware of drug-drug interactions. Education, computerized prescribing systems and drug information, collaborative drug selection, and pharmaceutical care are strongly encouraged for physicians and pharmacists.

Pharmacoepidemiologic study of potential drug interactions in outpatients of a university hospital in Thailand

BACKGROUND

Drug-drug interaction is a potential cause of adverse drug reactions. The incidence of such drug interactions in university hospitals in Thailand is unknown.

PURPOSE

To estimate the rate of potential drug-drug interactions in outpatients of a typical Thai university hospital, and to identify risk factors for such interactions in Thai patients.

METHODS

One-year outpatients' prescription data were retrieved from the hospital computer records. Potential drug interactions were identified using the existing drug-interaction database system. Potential interactions within a specific prescription and involving drugs prescribed 1-, 3- and 7-day earlier were searched for. Possible associations between occurrence of an interaction and a patient's age and gender and the number of items on the prescription were explored.

RESULTS

The overall rate of potential drug interactions was 27.9% with a maximal value of 57.8% at the Department of Psychiatry. The rate of the most potentially significant interactions was 2.6%, being the highest in the Department of Medicine (6.0%), with isoniazid vs. rifampin as the most common interacting combination. The rate increased with the patient's age and prescription size (P=0.000). The odd's ratio of having at least one potential drug interaction was 1.8 (64.2%) when age increased by 20 years (P=0.000) and 2.8 (165.7%) when another drug was added (P=0.000). The rate of potential drug interactions was the same for both genders. The rate of potential drug interactions detected across prescriptions was higher than within prescriptions and was dependent on the time interval between prescriptions.

CONCLUSIONS

Potential drug interactions were common in our sample of patients. The rate of such interactions increased with the number of drugs prescribed and the patient's age.

Inappropriate Medication Administration to the Acutely Ill Elderly: A Nationwide Emergency Department Study, 1992–2000

OBJECTIVES

To determine the national rate and trend of inappropriate medication administration to elderly emergency department (ED) patients. Secondary objectives were to identify risk factors for receiving an inappropriate medication and to determine whether administration is sometimes justified based on diagnosis.

DESIGN

Retrospective analysis of ED visits in the 1992-2000 National Hospital Ambulatory Medical Care Survey. Inappropriate medications identified using Beers' 1997 explicit criteria.

SETTING

EDs of U.S. noninstitutionalized general and short-stay hospitals.

PARTICIPANTS

ED survey patients aged 65 and older.

MEASUREMENTS

Magnitude and rate of administration of 36 medications.

RESULTS

Inappropriate medications were administered in an estimated 16.1 million (95% confidence interval (CI)=14.9-17.3 million) or 12.6% (95% CI=11.6-13.5%) of elderly ED visits from 1992 to 2000. The rate of inappropriate administration was unchanged throughout the study period (P=.40). Six drugs accounted for 70.8% of inappropriate administration: promethazine (22.2%), meperidine (18.0%), propoxyphene (17.2%), hydroxyzine (10.3%), diphenhydramine (7.1%), and diazepam (6.0%). In multivariate analysis, number of ED medications was the strongest predictor, with an odds ratio for two to three medications of 6.0 (95% CI=5.3-6.7) and for four to six medications of 8.1 (95% CI=7.2-9.2). Diagnoses indicating potentially appropriate uses of these medications were rarely present. For example, only 42.4% of patients receiving diphenhydramine and 7.4% receiving hydroxyzine were diagnosed with an allergic process.

CONCLUSION

Elderly ED patients are frequently administered inappropriate medications. Potentially appropriate uses of generally inappropriate drugs cannot account for such administrations. Inappropriate administration rates remain unchanged despite the 1997 publication of explicit criteria.

Adverse drug reactions as cause of admission to hospital: prospective analysis of 18 820 patients

OBJECTIVE

To ascertain the current burden of adverse drug reactions (ADRs) through a prospective analysis of all admissions to hospital.

DESIGN

Prospective observational study.

SETTING

Two large general hospitals in Merseyside, England.

PARTICIPANTS

18 820 patients aged > 16 years admitted over six months and assessed for cause of admission.

MAIN OUTCOME MEASURES

Prevalence of admissions due to an ADR, length of stay, avoidability, and outcome.

RESULTS

There were 1225 admissions related to an ADR, giving a prevalence of 6.5%, with the ADR directly leading to the admission in 80% of cases. The median bed stay was eight days, accounting for 4% of the hospital bed capacity. The projected annual cost of such admissions to the NHS is 466m pounds sterling (706m Euros, 847m dollars). The overall fatality was 0.15%. Most reactions were either definitely or possibly avoidable. Drugs most commonly implicated in causing these admissions included low dose aspirin, diuretics, warfarin, and non-steroidal anti-inflammatory drugs other than aspirin, the most common reaction being gastrointestinal bleeding.

CONCLUSION

The burden of ADRs on the NHS is high, accounting for considerable morbidity, mortality, and extra costs. Although many of the implicated drugs have proved benefit, measures need to be put into place to reduce the burden of ADRs and thereby further improve the benefit:harm ratio of the drugs.

Optimization of drug prescribing

The hazards of prescribing many drugs, including side-effects, drug interactions, and difficulties of compliance, have long been recognized as particular problems when prescribing for elderly people. The need for appropriate and rational prescribing for elderly patients has been prioritized in the National Service Framework for Older People. This review addresses the research evidence on epidemiology of prescribing in elderly patients, methods of measuring the quality, and the role of the prescriber and the multidisciplinary team in the day-to-day optimization of drug therapy.

Principles of drug therapy for the elderly patient

Physicians will treat larger numbers of elderly patients as the US population ages. Being treated simultaneously for more than 1 condition with multiple prescription drugs is only 1 reason why elderly patients are at greater risk of experiencing adverse drug reactions. The need for physicians to minimize the incidence of these reactions has become incumbent on both physicians and administrators. We review the underlying reasons why the elderly population is at risk of adverse drug reactions and summarize the principles of drug-drug interaction, metabolism, and distribution, which can help elderly patients receive proper pharmacological treatment.

Potentially inappropriate medication use by elderly Mexican Americans

BACKGROUND

Use of inappropriate medications by the elderly is a public health concern with potentially serious health consequences. Research indicates relatively high rates of inappropriate prescription drug usage for older whites and African Americans. However, rates for older Mexican Americans are unknown.

OBJECTIVE

To examine the prevalence and predictors of inappropriate prescription medication use by older Mexican Americans.

METHODS

A cross-sectional study of 3050 Mexican Americans aged > or =65 years living in the southwestern US was conducted. In-home interviews in 1993 and 1994 assessed prescription medication use. Descriptive statistics and logistic regression models were used to estimate prevalence and risk of inappropriate prescription drug use.

RESULTS

Approximately 12% (n = 365) of the sample had used at least 1 of 32 potentially inappropriate prescription medications within 2 weeks of the baseline assessment. Four drugs, chlorpropamide, propoxyphene, amitriptyline, and dipyridamole, accounted for 54% of all inappropriate prescribing. Unmarried subjects, those with >/=1 chronic diseases, high depressive symptoms, frequent physician visits, and combined Medicaid and Medicare insurance were more likely to have used at least 1 of the 32 potentially inappropriate drugs.

CONCLUSIONS

The prevalence of inappropriate medication use is lower in older Mexican Americans than in similar white and African American populations. More studies are needed on the pattern of inappropriate prescribing over time and on intervention programs to reduce potentially adverse health outcomes in older Mexican Americans most at risk.

Lack of awareness of community-acquired adverse drug reactions upon hospital admission : dimensions and consequences of a dilemma

OBJECTIVE

Adverse drug reactions (ADRs) are a well-known cause of hospital admission. Nevertheless a quantitative estimate of the preventability of and physicians' awareness of these reactions is lacking.

STUDY DESIGN AND METHODS

Using intensive bedside and computer-assisted drug surveillance methods a 13-month prospective pharmacoepidemiological survey was carried out on patients admitted to two medical wards of the Erlangen-Nuremberg University Hospital in Erlangen, Germany. This study aimed to define the incidence of preventable and unavoidable ADRs. In addition we investigated the awareness of the physicians to ADRs at the time of admission and the rate of contraindicated pre-admission prescriptions.

RESULTS

In 78 (8.5%) of 915 (10.9%) admissions a total of 102 (42 preventable) community-acquired ADRs were detected on admission. In 45 (3.8%) of the admissions ADRs led directly to hospitalisation. 56.9% of the ADRs were not recognised by the attending physician on admission. Marked correlation was found between the awareness of ADRs and their probability and severity scores (r = 0.85 and r = 0.94, respectively; p < 0.05). The most frequently detected ADRs were due to direct toxicity and secondary pharmacological effects. Idiosyncratic reactions were often missed and 18.6% of all drugs prescribed prior to admission were contraindicated. Leading the list were diuretics, analgesics/NSAIDs and antipsychotics/sedatives.

CONCLUSIONS

Awareness of existing ADRs on hospital admission and appropriate prescribing prior to hospital admission require attention. Early detection of ADRs on hospital admission can be achieved by the use of computer support systems. Many ADRs could be prevented by adhering to indications and contraindications.

Potential drug-drug interactions in the medication of medical patients at hospital discharge

OBJECTIVE

Information on the frequency of drug combinations with the potential to induce dangerous drug-drug interactions (DDIs) in patients discharged from the hospital is scarce. With the present study, we assessed the frequency and potential clinical significance of DDIs in the prescriptions of discharged medical patients.

METHODS

We retrospectively screened the medication for potential DDIs of 500 patients consecutively discharged with at least two prescriptions using a computerised drug-interaction program.

RESULTS

The 500 patients (56.6% male, mean age 67.0+/-15.9 years, median length of stay 13 days) were prescribed a median of six drugs (range 2-18) at discharge. Three hundred patients (60.0%; 95% confidence interval 55.7-64.3%) had at least one potentially interacting drug combination. Of 747 potential DDIs at discharge overall, 402 (53.8%) were new at the time of discharge due to a change of the medication during the hospital stay. Of these, 72 (17.9%) were of potentially minor, 281 (69.9%) of moderate and 49 (12.2%) of major severity. Of 44 patients with a potential DDI with major severity, 1 patient was re-hospitalised within 2 months after discharge due to a probable drug-related problem associated with the potential DDI.

CONCLUSIONS

Using a computerised drug-interaction program, a high proportion of patients was detected with at least one potential DDI in the medication prescribed at discharge. However, the proportion of DDIs associated with potentially relevant clinical consequences appeared to be relatively low.

Asthma medications and their potential adverse effects in the elderly: recommendations for prescribing

The incidence of drug-induced adverse effects is likely to increase as a result of advanced age and exposure of elderly patients to polypharmacy. Therefore, pharmacological therapy of asthma and chronic obstructive pulmonary disease (COPD) in the elderly patient can be potentially hazardous. beta(2)-agonists, administered as therapy for asthma and COPD, have recognised systemic sequelae, such as hypokalaemia and chronotropic effects, which may be life-threatening in susceptible patients. Adverse effects such as hypokalaemia can be aggravated by concomitant treatment with other drugs promoting potassium loss including diuretics, corticosteroids and theophyllines. In addition, relatively minor adverse events associated with the administration of beta(2)-agonists, such as tremor and blood pressure changes, may be of significance to the elderly patient leading to impairment in the quality of life. However, long-term treatment with beta(2)-agonists may reduce the incidence of drug-induced adverse effects as a result of beta-receptor subsensitivity. Oral and inhaled corticosteroids have been used for the treatment of acute asthma and COPD in the elderly patient. Long-term treatment with oral corticosteroids can result in serious systemic adverse effects such as suppressed adrenal function, bone loss, skin thinning and cataract formation. In contrast to beta(2)-agonists, oral corticosteroids can upregulate beta(2)-adrenoceptors and thereby potentiate the systemic sequelae of beta(2)-agonists. Hence, oral corticosteroids should be administered with caution for as short a duration as possible. Inhaled corticosteroids appear to be relatively well tolerated when administered at doses below approximately 1000 microg. However, larger doses of inhaled corticosteroids may affect hypothalamic-pituitary-adrenal function and bone turnover. In the case of inhaled corticosteroids, spacer devices, often used in older patients who cannot operate metered dose inhalers, can potentiate the systemic sequelae of both corticosteroids and beta(2)-agonists. The use of theophyllines in the treatment of COPD or chronic asthma is controversial. Theophyllines have a wide adverse effect profile and are prone to drug-drug interactions. The adverse effects may be mild or life threatening and include nausea and vomiting or sinus and supraventricular tachycardias. Therefore, theophyllines should be prescribed with extreme caution to elderly patients with asthma or COPD. In contrast, inhaled anticholinergic drugs such as ipratropium bromide and oxitropium bromide are generally safe in elderly patients and have useful bronchodilator function. Commonly reported adverse effects are an unpleasant taste and dryness of the mouth. When used as first-line therapy, anticholinergic drugs may optimise the bronchodilator effects of low-dose inhaled beta(2)-agonists in patients with chronic airflow obstruction, and hence obviate the need for higher doses.

Frequency and clinical outcome of potentially harmful drug metabolic interactions in patients hospitalized on internal and pulmonary medicine wards: focus on warfarin and cisapride

Drug metabolic interactions present potential risks in patient care, but their frequency and relative importance as a clinical problem remains unclear. To assess the frequency and clinical outcome of potentially harmful drug metabolic interactions in hospitalized patients, the authors performed a survey of the medication data of patients treated on internal and pulmonary medicine wards in a university hospital. The database was searched for concomitantly administered drug pairs that would, according to Hansten and Horn's drug interaction database, carry a high risk for a clinically harmful metabolic drug interaction. Coadministrations involving warfarin or cisapride were subjected to further analysis regarding clinical outcome. A total of 142 patients were exposed to 150 interactions with potentially harmful clinical outcome, resulting in a frequency of 0.9% (95% CI 0.7% to 1.0%). Inhibition of warfarin metabolism by metronidazole produced significant overanticoagulation as evidenced by elevated international normalized ratio values, whereas inducers (rifampicin and phenobarbital) of warfarin metabolism significantly reduced the efficacy of warfarin. One case of minor bleeding and one case of clavicular vein thrombosis were detected as possible consequences of disturbed anticoagulation. The coadministration of cisapride and erythromycin significantly prolonged the corrected QT (QTc) interval and was associated with clinical symptoms of cardiac arrhythmias. Coadministration of cisapride with fluconazole or miconazole was not associated with prolongation of the QTc interval or cardiac sequelae. Evaluations of patient materials are needed to assess the clinical relevance of metabolic drug interactions.

Assessing medication appropriateness in the elderly: a review of available measures

The disproportionate use of medications, combined with age-related pharmacokinetic and pharmacodynamic changes, places older adults at high risk for medication related problems (MRPs). MRPs demonstrate significant morbidity, mortality and economic impact among healthcare systems. The negative outcomes associated with MRPs emphasise the need for more careful and thorough assessments of drug therapy among older adults. In the 1990s a number of methods and instruments were developed to assist in the assessment of medication appropriateness. These tools may be categorised by criteria as: implicit, explicit or one utilising a combination of implicit and explicit criteria. This article reviews these available tools and outlines the advantages and disadvantages of each. In conclusion, those instruments considered to be comprised of both implicit and explicit criteria offer a more thorough assessment of medication appropriateness.

Evaluation of the elderly patient with weakness: an evidence based approach

Because of the altered physiology of the elderly population, either as a result of aging or as a result of other disease processes, many illnesses may present with features that are either atypical or nonspecific in nature. Difficult and nonspecific complaints such as weakness in an elderly patient must be handled in a judicious, cost-effective, comprehensive, and expeditious manner that benefits both the patient and the emergency department. This article addresses the evaluation of the elderly patient who presents to the ED complaining of weakness.

Predictors of medication use, compliance and symptoms of hypotension in a community-based sample of elderly men and women

OBJECTIVE

To investigate use of prescription and non-prescription drugs, predictors of drug use and symptoms of postprandial and postural hypotension were examined in 765 men and 846 women.

METHOD

A questionnaire mailed to 6324 subjects randomly chosen from the electoral roll.

RESULTS

Drug use, both prescription and non-prescription, was greater (P < 0.0001) in women (mean 4.1 total drugs, CI 3.9, 4.3) than in men (3.5 drugs, CI 3.3, 3.7); 41% of women and 36% of men used at least four drugs. Total drugs used were significantly greater in women (standardized regression coefficient (b) = 0.101, P < 0.0001), and increased with the number of diagnoses (b = 0.461, P < 0.0001) and taking antidepressants (b = 0.160, P < 0.0001). Use of non-prescription drugs was also greater in women (b = 0.094, P < 0.0001) and in association with arthritis (b = 0.053, P = 0.036) but decreased with age (b = -0.013, P < 0.0001). Potentially important drug interactions occurred in 10% of subjects and included hypoglycaemic agents with b-blockers and asthma with b-blockers. Symptoms of postprandial hypotension, reported in 2.6% of subjects, increased with the number of drugs used (OR 1.17, CI 1.05, 1.31) and with diabetes (OR 2.27, CI 1.05, 4.89). Symptomatic postural hypotension, recorded by 13% of subjects, related significantly to age (OR 1.04, CI 1.02, 1.06), tranquillisers (OR 1.98, CI 1.11, 3.54), antidepressants (OR 2.23, CI 1.30, 3.84) and ACE inhibitors (OR 2.14, CI 1.42, 3.22).

CONCLUSION

Reduction in the number and frequency of drug doses and better knowledge about drugs may improve compliance. Observed associations with polypharmacy or hypotension suggest possible approaches to decreasing drug-related illness and limiting the adverse effects of hypotension in the elderly.

Important drug-drug interactions in the elderly

Although drug-drug interactions constitute only a small proportion of adverse drug reactions, they are important because they are often predictable and therefore avoidable or manageable. Their frequency is related to the age of the patient, the number of drugs prescribed, the number of physicians involved in the patient's care and the presence of increasing frailty. The most important mechanisms for drug-drug interactions are the inhibition or induction of drug metabolism, and pharmacodynamic potentiation or antagonism. Interactions involving a loss of action of one of the drugs are at least as frequent as those involving an increased effect. It is likely that only about 10% of potential interactions result in clinically significant events and, while death or serious clinical consequences are rare, low-grade, clinically unspectacular morbidity in the elderly may be much more common. Nonspecific complaints (e.g. confusion, lethargy, weakness, dizziness, incontinence, depression, falling) should all prompt a closer look at the patient's drug list. There are a number of strategies that can be adopted to decrease the risk of potential clinical problems. The number of drugs prescribed for each individual should be limited to as few as is necessary. The use of drugs should be reviewed regularly and unnecessary agents withdrawn if possible, with subsequent monitoring. Patients should be encouraged to engage in a 'prescribing partnership' by alerting physicians, pharmacists and other healthcare professionals to symptoms that occur when new drugs are introduced. Physicians with a responsibility for elderly people in an institutional setting should develop a strategy for monitoring their drug treatment. For those interactions that have come to clinical attention, it is important to review why they happened and to plan for future prevention. Clinicians should also report, via the appropriate postmarketing surveillance scheme, any drug-drug interactions they have encountered. Finally, multidisciplinary education about the nature of physiological aging and its effect on drug handling, and the possible presentations of drug-related disease in older patients, is an important element in reducing interactions in the elderly.

Adverse drug reactions in the elderly and their prevention

Increasing age is often associated with multiple medical problems and therefore, the potential for increasing amounts of prescribed medication. Adverse reactions are a recognised hazard of drug therapy in elderly patients due to the amount of medication prescribed and the greater susceptibility of older people to adverse reactions. The problem is unlikely to diminish in the near future due to the proportionately increasing ageing population. Prevention of adverse drug reactions in the elderly deserves closer attention.

Obtaining the correct drug history

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Hookworms to treat haemachromatosis?

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Use of prescription medications in an elderly rural population: the MoVIES Project

OBJECTIVE

To determine the pharmacoepidemiology of prescription drug use in a rural elderly community sample, specifically the numbers and categories of medications taken and the factors associated with them.

DESIGN

Cross-sectional community survey.

SETTING

The mid-Monongahela Valley of southwestern Pennsylvania.

PARTICIPANTS

An age-stratified random sample of 1360 community-dwelling individuals, aged 65 years and older.

MEASURES

Self-reported use of prescription drugs demographic characteristics, and use of health services.

RESULTS

Nine hundred sixty-seven participants (71%) reported regularly taking at least one prescription medication and 157 (10%) reported taking five or more medications (median 2.0, range 0-13). Women took significantly more medications than men (median 2.0, range 0-13 and median 1.0, range 0-9, respectively; p = 0.01). The use of a greater number of medications was independently and statistically significantly associated with older age, hospitalization within the previous 6 months, home health care in previous year, visit to a physician within the previous year, and insurance coverage for prescription medication. Individuals older than 85 years were significantly more likely to be taking cardiovascular agents, anticoagulants, vasodilating agents, diuretics, and potassium supplements. Significantly more women than men were taking nonsteroidal antiinflammatory drugs, antidepressants, potassium supplements, and thyroid replacement medications.

CONCLUSIONS

Both the number and the types of prescription medications vary with age and gender. The demographic and health service use variables associated with greater medication use in the community may help define high-risk groups for polypharmacy and adverse drug reactions. Longitudinal studies are needed.

Central dimensions of clinical practice evaluation: efficiency, appropriateness and effectiveness--II

That a treatment selected for a given condition works, or that it works better than alternative treatments, or that it was selected because it works as well as but is cheaper than alternative treatments, should be of pivotal concern to clinicians and is of central concern to patients and to health care managers. Attempts to address these concerns have resulted in what is now widely termed the 'effectiveness movement'. The protagonists of the movement have been concerned to create a culture of evaluation and inquiry within which the formulation of evidence-based clinical guidelines and their introduction into routine practice have played a prominent part. The need to ensure cost effectiveness of clinical intervention has been at least as emphasized as the need to ensure the clinical effectiveness of health care interventions. Although cost-effectiveness analyses are now an indispensable feature of practice guideline formulation and treatment evaluation, few studies have examined any deterioration in patient outcome associated with successful cost containment. An adequate understanding of the concept of clinical effectiveness and the associated aims of the 'effectiveness movement' is central to an understanding of the future nature and extent of health service provision, not simply in the UK but also internationally. Having examined the concepts of efficiency and appropriateness previously (O'Neill, Miles & Polychronis 1996, Journal of Evaluation in Clinical Practice 2, 13-27) we move in this second of two articles to a detailed explanation of the concept of effectiveness, and to an examination of the derivation and use of clinical practice guideline, concluding with a consideration of the role of practice guidelines in ensuring the cost effectiveness of health care intervention. The reservation is expressed that a 'guidelines culture', when established, will be manipulated by health care commissioners for largely political purposes, creating a systematic bias in the purchasing process that will actively disadvantage a range of patient groups.