Drug development and use in the elderly: search for the right dose and dosing regimen (Parts I and II)

Therapeutic drug monitoring of perospirone: The lowest effective plasma concentration in patients with schizophrenia

OBJECTIVES

This study investigated the effects of demographic factors such as age, sex and comedications on the plasma concentrations of perospirone in individuals diagnosed with schizophrenia. Additionally, the relationship between these plasma levels and the clinical efficacy of the medication was explored.

METHODS

Data regarding the plasma concentration of perospirone in patients with schizophrenia were obtained from the Xi'an Mental Health Center and were retrospectively analysed.

RESULTS

The study results revealed a range of 0.50-1.59 ng/mL for the 25th-75th percentile of perospirone concentration in the plasma, which ranged from 0.07 to 6.0 ng/mL. The plasma concentration of perospirone increased with the daily oral dose (r = 0.283, P < 0.05). Furthermore, patients with higher plasma perospirone concentrations and concentration-to-dose ratios (C/D) tended to be older or were women. Notably, the coadministration of valproate significantly reduced perospirone concentration and the C/D ratio by 54.7% and 35.3%, respectively (P < 0.01). Receiver operating characteristics curve analyses revealed that patients exhibited a good clinical response when their plasma perospirone concentrations were ≥ 1.17 ng/mL.

CONCLUSION

The findings suggest that therapeutic drug monitoring of perospirone and adjustments to achieve steady-state concentrations of ≥ 1.17 ng/mL can be beneficial for optimising treatment for patients with schizophrenia.

Impact of medicine shortages on patients - a framework and application in the Netherlands

Background

Medicine shortages are often described in plain numbers, suggesting all shortages have a uniform impact. However, some shortages have a direct and serious effect on patients and need a prompt reaction from stakeholders. This study aims to create a broad framework to assess the impact of a shortage.

Method

We identified high impact shortages and selected exemplary shortages which we considered our learning cases. From five learning cases, we identified elements that had a potentially profound impact on one or more of these cases. We tested data saturation on the elements with another five test cases. Based on these elements, we created a framework to assess impact of shortages on patients and presented practical examples how to rate these different elements. Subsequently, we visualised the impact of these five learning cases on patients in radar charts.

Results

The five elements which we identified as potentially having a large impact were 1) alternative product, 2) disease, 3) susceptibility, 4) costs and 5) number of patients affected. The five learning cases rated high on different elements, leading to diverse and sometimes even opposite patterns of impact.

Conclusion

We created a framework for assessing the impact of a medicine shortage on patients by means of five key elements. By rating these elements, an indication of the impact can be obtained.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08765-x.

Profiling the most elderly parkinson's disease patients: Does age or disease duration matter?

BACKGROUND

Despite our ageing populations, elderly patients are underrepresented in clinical research, and ageing research is often separate from that of Parkinson's disease (PD). To our knowledge, no previous study has focused on the most elderly ('old-old', age ≥ 85 years) patients with PD to reveal how age directly influences PD clinical progression.

OBJECTIVE

We compared the clinical characteristics and pharmacological profiles, including complications of levodopa treatment, disease progression, disabilities, and comorbidities of the old-old with those of comparable younger ('young-old', age 60-75 years) PD patients. In addition, within the old-old group, we compared those with a short disease duration (< 10 years at the time of diagnosis) to those with a long disease duration ≥10 years to investigate whether prognosis was related to disease progression or aging.

METHODS

This single-centre, case-control study compared 60 old-old to 92 young-old PD patients, matched for disease duration. Patients in the old-old group were also divided equally (30:30) into two subgroups (short and long disease duration) with the same mean age. We compared the groups based on several clinical measures using a conditional logistic regression.

RESULTS

By study design, there were no differences between age groups when comparing disease duration, however, the proportion of men decreased with age (p = 0.002). At a comparable length of PD duration of 10 years, the old-old PD patients predominantly had significantly greater postural instability and gait disturbance (p = 0.006), higher motor scope of the Unified Parkinson's Disease Rating Scale (UPDRS-III, p<0.0001), and more advanced Hoehn & Yahr (H&Y) stage (p<0.0001). The Non-Motor Symptoms Questionnaire (NMSQuest) score was also significantly higher among the old-old (p<0.0001) compared to the young-old patients. Moreover, the distribution of NMS also differed between ages, with features of gastrointestinal problems (p<0.0001), urinary problems (p = 0.004), sleep disturbances and fatigue (p = 0.032), and cognitive impairment (p<0.0001) significantly more common in the old-old group, whereas sexual problems (p = 0.012), depression, and anxiety (p = 0.032) were more common in the young-old. No differences were found in visual hallucinations, cerebrovascular disease, and miscellaneous domains. While young-old PD patients received higher levodopa equivalent daily doses (p<0.0001) and developed a significant greater rate of dyskinesia (p = 0.002), no significant difference was observed in the rate of wearing-off (p = 0.378). Old-old patients also had greater disability, as measured by the Schwab and England scale (p<0.0001) and had greater milestone frequency specifically for dementia (p<0.0001), wheelchair placement (p<0.0001), nursing home placement (p = 0.019), and hospitalisation in the past 1 year (p = 0.05). Neither recurrent falls (p = 0.443) nor visual hallucinations (p = 0.607) were documented significantly more often in the old-old patients.

CONCLUSIONS

Age and disease duration were independently associated with clinical presentation, course, and progression of PD. Age was the main predictor, but disease duration also had a strong effect, suggesting that factors of the ageing process beyond the disease process itself cause PD in the most elderly to be more severe.

A Retrospective Analysis of Steady-State Olanzapine Concentrations in Chinese Patients Using Therapeutic Drug Monitoring: Effects of Valproate and Other Factors

BACKGROUND

The objective of this study was to investigate the serum concentrations of olanzapine in relation to age, sex, and other factors in Chinese patients aged between 10 and 90 years.

METHODS

Data for 884 olanzapine patients, deposited between 2016 and 2017, were retrieved from the therapeutic drug monitoring database of the Affiliated Brain Hospital of Guangzhou Medical University. The effects of covariates on serum olanzapine concentration, dose-normalized concentration (C/D ratio), and normalized concentration (C/D/weight) were investigated.

RESULTS

Generally, male patients had lower olanzapine concentration, C/D ratio, and C/D/weight than female patients (P < 0.001). Smoking and drinking reduced olanzapine concentration, C/D ratio, and C/D/weight (P < 0.001). Coadministration with valproate decreased olanzapine concentration, C/D ratio, and C/D/weight by about 16%, 30%, and 40%, respectively (P < 0.001). Patients younger than 60 years had higher olanzapine concentrations (P < 0.05) but lower C/D ratios and C/D/weight (P < 0.001) than patients older than 60 years. Age was correlated with olanzapine concentration (r = -0.082, P < 0.05), C/D ratio (r = 0.196, P < 0.001), and C/D/weight (r = 0.169, P < 0.001). Sample timing after dose and diagnostic factors also contributed to the olanzapine concentrations. Multiple linear regression analysis revealed significant influences of dosage, age, sex, valproate comedication, smoking, postdose interval, and schizophrenia (vs bipolar affective disorders) on serum olanzapine concentrations.

CONCLUSIONS

The metabolism of olanzapine may be altered by several factors. Patients characterized with a combination of factors may benefit from therapeutic drug monitoring for the adjustment of olanzapine dose to minimize adverse reactions.

Primary care physician's approach for mental health impact of COVID-19

As the world struggles to control coronavirus infection with the exhausting capacity of health care systems globally, the role of primary care physician and family physician becomes more important as the first point of contact with the community. Limited availability of mental health services in India requires general practitioners to deal with psychological disorders arising due to infection outbreak and its restrictive control strategies. This article discusses what and how primary physicians can manage the psychological burden of a pandemic, and therefore, reducing the reliance on mental health specialist.

To be ionized or not to be ionized: the vital role of physicochemical properties of galbanic acid derivatives in AChE assay

Alzheimer's disease is a progressive neurodegenerative disorder and patients suffer from memory loss, a decline in language skill and impairment in other cognitive functions. In the cholinergic hypothesis, dysfunction of cholinergic neurons especially in the hippocampus and cerebral cortex contributes to cognitive decline in patients. So agents that enhance acetylcholine concentration could improve cognitive function. AChEIs are among the most studied anti-Alzheimer agents. Galbanic acid as a natural compound with a sesquiterpene coumarin scaffold is a weak inhibitor of AChE. In the present contribution, we discussed the impact of carboxylic group ionization on inhibitory effects. We performed in vitro and in silico studies on galbanic acid, methyl and ethyl galbanates as AChE inhibitors. The order of inhibitory effect on AChE was obtained as ethyl galbanate ∼ methyl galbanate > galbanic acid. Our study highlights the important role of the physicochemical properties of natural lead compounds in each specific assay.Communicated by Ramaswamy H. Sarma.

Sedation with dexmedetomidine in elderly patients during dental surgery: a retrospective case series

Objectives

The number of elderly patients with systemic basal disease requiring invasive dental treatment has increased. Appropriate prediction of surgical invasiveness and combined use of psychosedation are thought to contribute to safe whole-body management. Dexmedetomidine (DEX) exhibits analgesic and anti-anxiolytic properties and causes mild respiratory depression. Studies regarding DEX use in elderly non-intubated patients are scarce. We aimed to use retrospective data to determine an effective dose of DEX to induce adequate sedation in elderly patients undergoing invasive dental surgery under local anesthesia.

Materials and Methods

One hundred two patients aged 70 to 96 years were presumably appropriately controlled with sedation. DEX was administered at an initial loading dose of 2.0 to 3.1 µg/kg/hr for 10 minutes. We divided the patients into five groups by age and compared their blood pressures and heart rates.

Results

In all five groups, blood pressure decreased suddenly at approximately 15 and 20 minutes after DEX administration. A marked decrease in blood pressure was noted in patients aged 75 to 79 years.

Conclusion

For elderly patients aged 75 years and above, the initial loading dose of DEX needs to be reduced to lower than half that required for young and middle-age adults.

Influence of age and renal impairment on the steady state pharmacokinetics of filgotinib, a selective JAK1 inhibitor

Aims

Filgotinib (GS‐6034, formerly GLPG0634) is an oral, selective Janus kinase 1 (JAK1) inhibitor that showed early response and sustained efficacy in patients with rheumatoid arthritis and with Crohn's disease. The aim of the present study was to investigate the impact of age and renal impairment (RI) on the pharmacokinetics (PK) of filgotinib and its main metabolite.

Methods

The effect of age was assessed in two groups of 10 elderly healthy subjects (65–74 and ≥75 years of age) and a control group of 10 younger healthy subjects (40–50 years of age). The impact of RI was investigated in three groups of subjects with mild (n = 6), moderate (n = 6) and severe (n = 3) RI [estimated glomerular filtration rate (eGFR) 60–89, 30–59 and 15–29 ml min^–1 1.73 m^–2, respectively] and a control group (n = 9) with normal renal function (eGFR ≥90 ml min^–1 1.73 m^–2). The PK of filgotinib and its metabolite were evaluated following filgotinib 100 mg once‐daily doses for 10 days.

Results

At steady state, the exposure [area under the concentration–time curve over the dosing interval (AUC_0–24 h)] of filgotinib and its metabolite was moderately higher (1.45‐ and 1.33‐fold, respectively) in the elderly subjects (≥75 years) compared with younger subjects. Renal clearance for filgotinib and its metabolite decreased with the degree of RI, leading to a maximum increase in AUC_0–24 h of 1.54‐fold for filgotinib and 2.74‐fold for the metabolite in subjects with severe RI. Filgotinib was generally safe and well tolerated.

Conclusions

Age and mild to moderate impairment of renal function had limited impact on the PK of filgotinib. In subjects with severe RI, the exposure to the metabolite of filgotinib was elevated, consistent with its renal elimination pathway.

Challenges and innovations of drug delivery in older age

Both drug delivery performance and various age-related physical, mental and physiological changes can affect drug effectiveness and safety in elderly patients. The many drug delivery systems developed over the years include recent novel transdermal, nasal, pulmonary and orally disintegrating tablets that provide consistent, precise, timely and more targeted drug delivery. Certain drug delivery systems may be associated with suboptimal outcomes in the elderly because of the nature of drug present, a lack of appreciation of the impact of age-related changes in drug absorption, distribution and clearance, the limited availability of pharmacokinetic, safety and clinical data. Polypharmacy, patient morbidity and poor adherence can also contribute to sub-optimal drug delivery systems outcomes in the elderly. The development of drug delivery systems for the elderly is a poorly realised opportunity, with each system having specific advantages and limitations. A key challenge is to provide the innovation that best meets the specific physiological, psychological and multiple drug requirements of individual elderly patients.

Prevalence and Implications of Abnormal Laboratory Results in Patients in the Terminal Phase of Life

BACKGROUND

Pathophysiological changes at the end of life may affect pharmacokinetics of drugs. However, caregivers typically do not extensively monitor patients' laboratory parameters at the end of life.

OBJECTIVE

Our aim was to describe laboratory parameters of hospice patients in the week before death.

METHODS

A cohort study was conducted on available laboratory results in the week before death, including clinical chemistry and hematology tests.

RESULTS

Laboratory data of 125 patients in a palliative care center were included, assessed at a median of 3 days before death. Eighty percent of patients had anemia and almost all had hypoalbuminemia (97%). Elevated levels of gamma-glutamyl transferase (gGT) were found in 75%, of alkaline phosphatase (ALP) in 60%, of aspartate aminotransferase (ASAT) in 60%, and of calcium (Ca) in 68%. Alanine aminotransferase (ALAT), bilirubin, sodium (Na), and potassium (K) were abnormal in from 8.8% to 36.0% of patients. A previous unknown poor kidney function was found in 60% of patients. Thirteen patients (22%) with a regular morphine prescription and one patient treated with a non-steroidal anti-inflammatory drug (NSAID) had severe kidney failure.

CONCLUSIONS

Abnormal laboratory results were expected due to the pathophysiological changes that occur during the last phase of life. Remarkably, however, electrolytes (Na and K) were balanced even shortly before death. Estimated glomerular filtration rate (eGFR), reflecting the kidney function, seems the most clinically relevant laboratory parameter, because it may guide drug choice and dosing.

Effects of age and gender on the serum levels of clozapine, olanzapine, risperidone, and quetiapine

OBJECTIVE

To investigate serum concentrations of second-generation antipsychotics in relation to age and gender in a population ranging from 18 to 100 years.

METHOD

Results from a routine therapeutic drug monitoring database were retrieved, and 43 079 samples from 11 968 patients were included (17 249 samples for clozapine, 16 171 samples for olanzapine, 5343 samples for risperidone, and 4316 samples for quetiapine). The dose-adjusted concentration was used as the primary target variable. A linear mixed model was used to allow the inclusion of multiple samples from each patient.

RESULTS

Age had a significant impact on the concentrations of all four drugs. At the age of 80, the dose-adjusted concentrations were up to twice those of the age of 40. At the age of 90, dose-adjusted concentrations were two- to three-fold higher. Age-related increases were largest for clozapine (+108% at 80 years; +197% at 90 years) and smallest for olanzapine (+28% at 80 years; +106% at 90 years). Females generally had dose-adjusted concentrations 20-30% higher than males.

CONCLUSION

The effect of age on the serum concentrations of the antipsychotics studied becomes pronounced with advanced age. The patient population aged above 70 should be subdivided according to exact age, and considerable dose reductions are recommended.

Comparison between the Effect of Cow Ghee and Butter on Memory and Lipid Profile of Wistar Rats

INTRODUCTION

The traditional texts designate Cow Ghee as Medhya Rasayana, beneficial for mental alertness and memory. There has been concern about increased risk of cardiovascular disease due to its high percentage of saturated fatty acids in ghee. Amongst all edible fats, nutrition composition of cow ghee and butter is comparatively similar. Hence we had planned a study to assess effect of cow ghee on memory and lipid profile.

AIM

So the aim of this study is to assess the effect of cow ghee on memory and lipid profile.

MATERIALS AND METHODS

Nootropic activity of test drugs was assessed by Elevated Plus Maze (EPM) and Morris Water Maze (MWM) model. Rats were divided into four groups namely control, Piracetam, cow ghee and butter. All drugs were given orally for 21 days. Transfer latency was measured in EPM model and probe test was done in MWM model.

RESULTS

Cow ghee and butter group showed no significant effect on memory in EPM and MWM model. There was reduction in weight of animals in Cow Ghee group and increase in weight with Butter. In both the models there was a significant increase in Triglyceride (TG) and Very Low Density Lipoproteins (VLDL) levels of rats in butter groups and increase in TG and VLDL of rats with cow ghee in EPM model.

CONCLUSION

The result of experiment suggests that no beneficial effect cow ghee and butter on cognition was seen. However, ghee is relatively safer when compared to Butter in considering lipid profile.

Drug Utilization and Inappropriate Prescribing in Centenarians

OBJECTIVES

To use primary care electronic health records (EHRs) to evaluate prescriptions and inappropriate prescribing in men and women at age 100.

DESIGN

Population-based cohort study.

SETTING

Primary care database in the United Kingdom, 1990 to 2013.

PARTICIPANTS

Individuals reaching the age of 100 between 1990 and 2013 (N = 11,084; n = 8,982 women, n = 2,102 men).

MEASUREMENTS

Main drug classes prescribed and potentially inappropriate prescribing according to the 2012 American Geriatrics Society Beers Criteria.

RESULTS

At the age of 100, 73% of individuals (79% of women, 54% of men) had received one or more prescription drugs, with a median of 7 (interquartile range 0-12) prescription items. The most frequently prescribed drug classes were cardiovascular (53%), central nervous system (CNS) (53%), and gastrointestinal (47%). Overall, 32% of participants (28% of men, 32% of women) who received drug prescriptions may have received one or more potentially inappropriate prescriptions, with temazepam and amitriptyline being the most frequent. CNS prescriptions were potentially inappropriate in 23% of individuals, and anticholinergic prescriptions were potentially inappropriate in 18% of individuals.

CONCLUSION

The majority of centenarians are prescribed one or more drug therapies, and the prescription may be inappropriate for up to one-third of these individuals. Research using EHRs offers opportunities to understand prescribing trends and improve pharmacological care of the oldest adults.

Effect of age on drug metabolism in women with breast cancer

INTRODUCTION

The aging of the population will increase the number of breast cancer patients requiring treatment in both the adjuvant and metastatic setting. Hormones, chemotherapy and targeted drugs all have a role in treatment. Older patients have been underrepresented in clinical trials making evidence-based decisions difficult. The increase in comorbidity and aging, polypharmacy and changes in function make pharmacotherapy decisions more complicated. Knowledge of the issues is critical in the prescribing of effective and safe therapy. There are factors associated with advancing age that can result in pharmacokinetic and pharmacodynamic variations in processing of hormonal agents, chemotherapy and targeted drugs.

AREAS COVERED

A review of the literature pertaining to pharmacokinetic changes in aging in breast cancer was untaken. Studies are reviewed involving single agents and some combinations.

EXPERT OPINION

Older patients should be considered for standard therapies. Their specific problems need to be evaluated by geriatric-specific assessment including functional status, end organ dysfunction and polypharmacy. There are few instances for age-related changes in pharmacokinetics and when present are usually not clinically significant. When changes are present, they are often the result of comorbidity, drug interactions and drug scheduling issues. The older patients may be more sensitive to certain toxicities such as cardiac toxicity, neuropathy and myelosuppression.

How pre-marketing data can be used for predicting the weight of drug interactions in clinical practice

Unexpected drug interactions have led to the withdrawal of many drugs, raising concern about the gap between what is known at the time of approval and the risk of serious effects in the longer term, particularly in high-risk populations generally excluded from drug development. This is because the majority of drug interaction studies are done using in vitro methods, or in healthy young volunteers who may not reflect the complexity of patients, and the settings in which the drug will be used in clinical practice. Pre-marketing interaction studies should therefore be designed to make information easily accessible and clinically transferable. They should be adequate in terms of sample size, population, comorbidity, phenotyping and/or genotyping, end-points and outcome measures, and conducted in conditions of dose, route and timing of co-administration that reproduce the proposed therapeutic indications of the new drug. Although young volunteers have the advantage of minimizing some confounding effects introduced by diseases or polypharmacy, patients drawn from populations for whom the drug is intended would be more relevant and accurate, providing the studies are feasible and safe.

Lower-dose prescribing: minimizing "side effects" of pharmaceuticals on society and the environment

The prescribed use of pharmaceuticals can result in unintended, unwelcomed, and potentially adverse consequences for the environment and for those not initially targeted for treatment. Medication usage frequently results in the collateral introduction to the environment (via excretion and bathing) of active pharmaceutical ingredients (APIs), bioactive metabolites, and reversible conjugates. Imprudent prescribing and non-compliant patient behavior drive the accumulation of unused medications, which pose major public health risks from diversion as well as risks for the environment from unsound disposal, such as flushing to sewers. The prescriber has the unique wherewithal to reduce each of these risks by modifying various aspects of the practice of prescribing. By incorporating consideration of the potential for adverse environmental impacts into the practice of prescribing, patient care also could possibly be improved and public health better protected. Although excretion of an API is governed by its characteristic pharmacokinetics, this variable can be somewhat controlled by the prescriber in selecting APIs possessing environment-friendly excretion profiles and in selecting the lowest effective dose. This paper presents the first critical examination of the multi-faceted role of drug dose in reducing the ambient levels of APIs in the environment and in reducing the incidence of drug wastage, which ultimately necessitates disposal of leftovers. Historically, drug dose has been actively excluded from consideration in risk mitigation strategies for reducing ambient API levels in the environment. Personalized adjustment of drug dose also holds the potential for enhancing therapeutic outcomes while simultaneously reducing the incidence of adverse drug events and in lowering patient healthcare costs. Optimizing drug dose is a major factor in improving the sustainability of health care. The prescriber needs to be cognizant that the "patient" encompasses the environment and other "bystanders," and that prescribed treatments can have unanticipated, collateral impacts that reach far beyond the healthcare setting.

Use of potentially inappropriate medicines in elderly: A prospective study in medicine out-patient department of a tertiary care teaching hospital

Objective:

The present study was undertaken with the aim to detect extent of drug use in elderly at medicine outpatient department at tertiary care hospital and to evaluate inappropriate prescribing with the help of Beers' criteria 2002.

Materials and Methods:

The study was carried out at medicine out patient department of our hospital. 407 geriatric patients were included during the study period of three and half months. The data was collected in a proforma which included the patients' details and the prescriptions.

Results:

The results reveal that 7.42% of total drugs were prescribed in an inappropriate manner and 23.59% of total patients received at least one inappropriate drug prescription. Administration of a drug which is avoided in elderly forms a common category of inappropriate drug use. Antihistamines, anticholinergic, sedatives and hypnotics and cardiac glycosides are the most common drug groups prescribed in inappropriate manner.

Conclusion:

To conclude, this study shows high prevalence of inappropriate use of drugs in geriatric practice suggesting urgent need for sincere efforts to improve the situation.

Digoxin therapy in the elderly: pharmacokinetic considerations in nursing

Digoxin is effective in controlling ventricular rhythm in atrial fibrillation and is used in heart failure when angiotensin converting enzyme inhibitors and diuretics are ineffective. Because use of more than 1 drug is often required with these conditions, pharmacokinetic considerations, including those related to complementary medicine, are important. Increased awareness of drug action in the elderly is important because there is often an increase in body fat and leaner muscle mass as well as changes in organ function, such as that of the kidney, which alters drug activity. Nurses have an important role to play in the safe administration of digoxin.

Predicting the clinical relevance of drug interactions from pre-approval studies

Drug interactions (DIs) may result in adverse drug events that could be prevented, but in many cases the available information on potential DIs is not easily transferable to clinical practice. The majority of studies date from preclinical or premarketing phases, using animals or human-derived sources that may not accurately reflect the growing clinical complexity of high-risk populations, such as the elderly, women, children, patients with chronic disease, polytherapy and impaired organ functions. Thus, at the time of approval of a new drug the information in the summary of product characteristics refers to potential DIs, but lacks specific management recommendations and is of limited clinical utility. Therefore, we set out to review in vitro and in vivo methods to predict and quantify potential DIs, to see whether these studies could help the physician tackle daily problems of the assessment and choice of combined drug therapies, and to propose, from a clinical point of view, how premarketing studies could be improved so as to help the physician at the patient's bedside. Preclinical and premarketing study design needs to be improved to make information easily accessible and clinically transferable. Studies should also take into account appropriate sample size, duration, co-morbidity, number of coadministered drugs, within- and between-subject variability, specific at-risk populations and/or drugs with a relatively narrow therapeutic window, and clinical endpoints. After premarketing development in situations where there is potential high risk of serious adverse events, specific phase IV studies (and/or active pharmacovigilance studies) should be required to monitor and quantitatively assess their clinical impact.

Clinical pharmacology of analgesics in old age and frailty

There is a high prevalence of pain in older people. Optimal assessment and management of pain in this population is challenging. The pharmacokinetics and pharmacodynamics of analgesic medications are affected by ageing and frailty, as well as by intercurrent medical conditions and their treatments. This review describes what is currently understood about the impacts of old age and frailty on the clinical pharmacology of commonly used analgesics, to provide a rational basis for the use of these medicines. In view of the wide age-related inter-individual variability in pharmacokinetics and pharmacodynamics of analgesic medications, monitoring of clinical response and adverse effects is essential to optimize pain control in older people.

Potential prescription patterns and errors in elderly adult patients attending public primary health care centers in Mexico City

Introduction

Six out of every 10 elderly persons live in developing countries.

Objective

To analyze and assess the drug prescription patterns and errors in elderly outpatients attending public health care centers in Mexico City, Mexico.

Materials and methods

A descriptive and retrospective study was conducted in 2007. Fourteen hundred prescriptions were analyzed. Prescriptions of ambulatory adults aged >70 years who were residents of Mexico City for at least two years were included. Prescription errors were divided into two groups: (1) administrative and legal, and (2) pharmacotherapeutic. In group 2, we analyzed drug dose strength, administration route, frequency of drug administration, treatment length, potential drug–drug interactions, and contraindications. Variables were classified as correct or incorrect based on clinical literature. Variables for each drug were dichotomized as correct (0) or incorrect (1). A Prescription Index (PI) was calculated by considering each drug on the prescription. SPSS statistical software was used to process the collected data (95% confidence interval; p <0.05).

Results

The drug prescription pattern in elderly outpatients shows that 12 drugs account for 70.72% (2880) of prescribed drugs. The most prescribed drugs presented potential pharmacotherapeutic errors (as defined in the present study). Acetylsalicylic acid–captopril was the most common potential interaction (not clinically assessed). Potential prescription error was high (53% of total prescriptions). Most of the prescription errors were due to omissions of dosage, administration route, and length of treatment and may potentially cause harm to the elderly outpatients.

Conclusions

A high number of potential prescription errors were found, mainly due to omissions. The drug prescription pattern of the study population is mainly constituted by 12 drugs. The results indicate that prescription quality depends on the number of prescribed drugs per prescription (p < 0.000).

To scale or not to scale: the principles of dose extrapolation

The principles of inter-species dose extrapolation are poorly understood and applied. We provide an overview of the principles underlying dose scaling for size and dose adjustment for size-independent differences. Scaling of a dose is required in three main situations: the anticipation of first-in-human doses for clinical trials, dose extrapolation in veterinary practice and dose extrapolation for experimental purposes. Each of these situations is discussed. Allometric scaling of drug doses is commonly used for practical reasons, but can be more accurate when one takes into account species differences in pharmacokinetic parameters (clearance, volume of distribution). Simple scaling of drug doses can be misleading for some drugs; correction for protein binding, physicochemical properties of the drug or species differences in physiological time can improve scaling. However, differences in drug transport and metabolism, and in the dose-response relationship, can override the effect of size alone. For this reason, a range of modelling approaches have been developed, which combine in silico simulations with data obtained in vitro and/or in vivo. Drugs that are unlikely to be amenable to simple allometric scaling of their clearance or dose include drugs that are highly protein-bound, drugs that undergo extensive metabolism and active transport, drugs that undergo significant biliary excretion (MW > 500, ampiphilic, conjugated), drugs whose targets are subject to inter-species differences in expression, affinity and distribution and drugs that undergo extensive renal secretion. In addition to inter-species dose extrapolation, we provide an overview of dose extrapolation within species, discussing drug dosing in paediatrics and in the elderly.

Clinical pharmacology of cancer therapies in older adults

This abbreviated review outlines the physiologic changes associated with aging, and examines how these changes may affect the pharmacokinetics and pharmacodynamics of anticancer therapies. We also provide an overview of studies that have been conducted evaluating the pharmacology of anticancer therapies in older adults, and issue a call for further research.

A composite screening tool for medication reviews of outpatients: general issues with specific examples

Regular performance of medication reviews is prominent among methods that have been advocated to reduce the extent and seriousness of drug-related problems, such as adverse drug reactions, drug-disease interactions, drug-drug interactions, drug ineffectiveness and cost ineffectiveness. Several screening tools have been developed to guide practising healthcare professionals and researchers in reviewing the medication patterns of elderly patients; however, each of these tools has its own limitations. This review discusses a wide range of general prescription-, treatment- and patient-related issues that should be taken into account when reviewing medication patterns by implicit screening. These include generic and therapeutic substitution; potentially superfluous or inappropriate medications; potentially inappropriate dosages or duration of treatment; drug-disease and drug-drug interactions; under-treatment; making use of laboratory test results; patient adherence, experiences and habits; appropriate dosage forms and packaging. A broad selection of specific examples and references that can be used as a basis for explicit screening of medication patterns in outpatients is also offered.

Pharmacokinetic-Pharmacodynamic Crisis in the Elderly

Advances in medical technology have led to improved survival after catastrophic illnesses. Many of the survivors require ongoing care including tracheostomy, mechanical ventilation, tube feedings, and indwelling venous catheters. Repeated hospitalizations may be necessary to treat infectious complications resulting from resistant organisms requiring intravenous antibiotic therapy. Because prolonged intravenous access may be difficult or even impossible in these patients, alternative means of therapy are necessary. Linezolid is the first of a new class of antimicrobial agents known as the oxazolidinones with activity against gram-positive bacteria similar to that of vancomycin and yet its oral bioavailability allows for enteral administration. We present our retrospective experience with oral linezolid in a cohort of pediatric intensive care unit patients. Primary infectious disease issues included endocarditis, tracheitis, pneumonia, or central line sepsis resulting from Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus, and Enterococcus. Treatment was initiated with vancomycin and changed to enteral linezolid (10 mg/kg every 12 hours). The duration of therapy with linezolid varied from 7 days to 6 weeks. All of the patients were discharged home to complete their course of enteral linezolid. No complications related to linezolid therapy were noted, and all of the patients completed their prescribed course of therapy without the need for rehospitalization. Our preliminary experience suggests that oral linezolid offers an effective alternative to intravenous vancomycin for the treatment of infections resulting from gram-positive bacteria and avoids the need for prolonged vascular access.

Drug-nutrient interactions in elderly people

PURPOSE OF REVIEW

The presence of multiple diseases, polypharmacy, malnutrition, and impaired metabolism in elderly individuals increases the risks of adverse events related to drug-food interactions. Some considerations for elderly people influenced by drug-food interactions are reviewed.

RECENT FINDINGS

When investigating pharmacokinetic and pharmacodynamic modifications in the elderly, other factors have to be considered, such as anorexia, dementia, depression, intolerance, gastrointestinal-tract disorders, social and economic factors, reduced abilities (visual and manual) and difficulties in chewing or swallowing. Specific reference is made herein to the health status of the elderly Brazilian population based on the observations of our research group. In addition, the most common diseases (such as cancer, coronary heart disease, dementia, diabetes mellitus, hypertension and osteoporosis), the drugs usually prescribed to treat them, and the adverse nutritional reactions that occur in older patients are summarized.

SUMMARY

In order to develop a correct drug prescription plan and nutritional intervention to avoid any kind of undesirable drug-food interaction effect, it is necessary to adequately diagnose the disease and often re-evaluate the chosen treatment, identify disease stages and the necessary therapies to minimize the number of drugs administered, and select a reasonable nutritional assessment.

Metabolism and pharmacokinetics in children and the elderly

In drug development, clinical trials are commonly carried out in either healthy volunteers or carefully selected patients. However, it has been recognised for a long time that both extremes of age, children and elderly, display a number of important metabolic and pharmacokinetic differences as compared with adults. This also has important consequences as to the toxic reactions and risk assessment of chemicals. What is known, what is not known and what should we do to improve the situation?

Drug dosage in the elderly: dermatological drugs

Drug pharmacokinetics and pharmacodynamics may be altered in the elderly. An important contribution is made by decreased renal function, but biotransformation in the liver may also play a role. Commonly prescribed dermatological drugs such as methotrexate and cetirizine are likely to be eliminated more slowly in the elderly and potentially hepatotoxic drugs such as itraconazole and acitretin should be used with caution. Altered drug distribution as a result of body composition changes can lead to prolonged half-life or higher plasma concentrations of many drugs. Higher prevalence of adverse drug reactions and multidrug regimens, and large interindividual variability in drug response make drug dosage and administration in the elderly challenging. New immunobiological agents such as alefacept, efalizumab and etanercept, which are approved for treatment of psoriasis, seem to be as well tolerated in the elderly as in younger patients. A recommended approach when prescribing drugs to the elderly would be to start with a small initial dose and to reduce the number of drugs administered simultaneously. It is crucial to simplify the drug regimen as much as possible in order to enhance drug management in the elderly. To improve pharmacotherapy in the elderly, we review age-related changes in pharmacokinetics that are likely to play a role in dermatological practice.

The risks of warfarin use in the elderly

The use of warfarin in the elderly, particularly for stroke prevention in chronic atrial fibrillation, is steadily increasing. Although the benefits of warfarin are greatest in the elderly, so are the risk of adverse outcomes and the difficulties of anticoagulant management. Clinical systems need to improve to counter this therapeutic dilemma, as warfarin is likely to remain the only widely available oral anticoagulant for the foreseeable future. Aspects that require attention are: the careful selection of patients in whom treatment with warfarin is appropriate; initiating therapy in a low dose (e.g., 2.5-5 mg/day); thorough education of patients and carers; close monitoring, especially with any change in the patient's regular drug therapy; involving patients more in the management of their warfarin therapy (self-monitoring/management in suitable patients); and ongoing review of the appropriateness of therapy as circumstances change.

Mechanistic basis of adverse drugreactions: the perils of inappropriate dose schedules

Adverse drug reactions (ADRs) have long been recognised as a significant cause of morbidity and mortality. They account for a substantial number of clinical consultations, hospital admissions and extended duration of in-patient stay as well as mortality. By far the most common ADRs are the concentration-dependent pharmacological reactions, the majority of which ought to be preventable. As a result of high concentrations of the parent drug and/or its metabolite(s), there is an augmentation of primary pharmacological activity and/or appearance of new and undesirable secondary pharmacological activity. Typically, these high concentrations result from administration of high doses in an attempt to maximise efficacy and/or modulation of the pharmacokinetics of a drug by either genetic or non-genetic factors. High plasma concentrations of parent drug may result from inherited impairment or drug-induced inhibition of its pharmacokinetic disposition. Conversely, inherited overcapacity or drug-induced induction of the metabolism of a drug may result in low concentrations of parent drug and frequently, rapid accumulation of its metabolites. Environmental, dietary and phytochemical factors may also influence the activity of drug metabolising enzymes. As with inherited polymorphisms of acetylation and cytochrome P450-based drug metabolising enzymes, polymorphisms of other conjugation reactions, such as glucuronidation, increasingly appear to be associated with drug toxicity. Diseases of organs involved in elimination of a drug also alter its pharmacokinetics, plasma concentration and, therefore, the profile of its concentration-dependent ADRs. Inherited mutations, concurrently administered drugs or presence of certain diseases may also alter the sensitivity of some pharmacological targets, accounting for a substantial number of ADRs and interactions. When there is enhanced pharmacodynamic sensitivity, plasma drug concentrations that are apparently within the normal 'non-toxic' range give rise to ADRs. Recent advances have also provided important insights into the wider scope of drug-drug interactions. Interactions that occur at P-glycoproteins, drug transporters and efflux pumps, at various transmembrane interfaces such as the gastrointestinal wall, renal tubules, hepatobiliary border and blood-brain barrier, are beginning to explain many non-metabolic interactions. These alter the systemic exposure to drugs and have so far, begun to explain unexpected neurotoxicity and hepatotoxicity. The function of these transporters is also genetically modulated. These advances, together with continued increased awareness and education of prescribers and pharmacists, offer great opportunities for substantially minimising concentration-related ADRs.

Cardiovascular Drug Therapy in Elderly Patients

An increasing number of elderly patients are exposed to cardiovascular drugs for the treatment of acute and/or chronic conditions. This is a result of the progressive aging of the population, a common feature in most industrialised countries, and an improvement in primary and secondary cardiovascular prevention strategies with increased survival rates. Traditionally, most elderly patients receiving cardiovascular drugs had advanced cardiac, liver and kidney disease that significantly influenced drug pharmacokinetic and pharmacodynamic parameters. Currently, however, many patients without significant organ impairment receive cardiovascular therapy for primary or early secondary prevention (i.e. increased vascular risk, asymptomatic left ventricular dysfunction, poststroke phase, type 2 diabetes mellitus), highlighting the need for a better understanding of specific age-related pharmacokinetic and pharmacodynamic effects. A systematic review has been conducted on the specific effects of aging, in the absence of major co-morbidities, on the pharmacokinetic and pharmacodynamic properties of traditional and newer cardiovascular drugs. Currently, the evidence available is poor or nonexisting for several drugs and mainly derived from very small and underpowered studies, thus limiting data interpretation. In particular, there is very little information on patients >80 years of age, thus raising important concerns about the correct use of these drugs in this constantly growing population.