Clinical pharmacology in an aging population

Frailty Status and Polypharmacy Predict All-Cause Mortality in Community Dwelling Older Adults in Europe

European population ageing is associated with frailty, a complex geriatric syndrome, and polypharmacy, both resulting in adverse health outcomes. In this study we aimed to evaluate the impact of frailty and polypharmacy, on mortality rates, within 30 months, using a cohort of SHARE participants aged 65 years old or more. Frailty was assessed using a version of Fried’s phenotype criteria operationalized to SHARE while polypharmacy was defined as taking five or more drugs per day. We found a prevalence of 40.4% non-frail, 47.3% pre-frail and 12.3% frail participants. Moreover, a prevalence of polypharmacy of 31.3% was observed, being 3 three times more prevalent in frail individuals and two times in pre-frail individuals, when compared with non-frail. Individuals with both conditions had shown higher mortality rates. Comparing with non-polymedicated non-frail individuals all the other conditions are more prone to die within 30 months. Polymedicated older and male participants exhibited also higher mortality rates. This work shows polypharmacy and frailty to be associated with a higher risk of all-cause of mortality and highlights the need to decrease ‘unnecessary’ polypharmacy to reduce drug-related issues and also the need to assess frailty early to prevent avoidable adverse outcomes.

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.

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.

Polypharmacy in the Elderly: A Marker of Increased Risk of Mortality in a Population-Based Prospective Study (NEDICES)

BACKGROUND

Little information is available on the potential association between polypharmacy and risk of mortality.

OBJECTIVE

To determine in a population-based study whether polypharmacy is associated with increased risk of mortality in elderly persons.

METHODS

In this population-based, prospective study of 5,052 people aged 65 years and older (Neurological Disorders in Central Spain), current medications were recorded. Cox proportional hazards models, adjusted for sociodemographics and comorbidity factors, were used to assess the risk of death up to 13.3 years later, comparing the polypharmacy group (≥6 drugs) to those who were taking 1-5 drugs and those in a nonmedicated group (0 drugs).

RESULTS

Out of 5,052 participants, 2,550 (50.5%) died over a median follow-up of 6.5 years, including 361 (28.8%) deaths among 931 nonmedicated participants, 1,946 (51.4%) deaths among 3,787 participants taking 1-5 drugs daily, and 243 (72.8%) among 334 participants on polypharmacy. In an unadjusted Cox model, risk of mortality was increased in participants on polypharmacy [hazard ratio (HR) = 2.78, 95% confidence interval [CI]: 2.36-3.27, p < 0.001) and in those taking between 1 and 5 drugs (HR = 1.47, 95% CI: 1.31-1.64, p < 0.001) versus those who were nonmedicated (reference group). In a Cox model that adjusted for a variety of demographic factors and comorbidities, HR remained increased in participants on polypharmacy (HR = 1.83, 95% CI: 1.51-2.21, p < 0.001).

CONCLUSION

This study provides evidence that polypharmacy is associated with increased risk of mortality in elderly people. The extent to which polypharmacy is the proximate cause rather than a marker of this increase risk remains to be determined.

District nurses’ preventive home visits to 75-year-olds: An opportunity to identify factors related to unsafe medication management

Aims: To investigate factors related to unsafe medication management among 75-year-olds during preventive home visits, and to describe the interventions district nurses used. Methods: An explorative study. During a 9- to 12-month period, 36 DNs used the Safe Medication Assessment (SMA) tool during preventive home visits to 75-year-olds who used at least one drug ( n=113). Results: One or more factors related to unsafe medication management were identified in 84% of the 75-year-olds. More than 40% used five or more drugs, and 34.5% reported symptoms potentially indicative of adverse effects of their drugs. Nearly 30% had prescribers from more than two medical units, and 7.1% of the older persons were appraised as having reduced cognitive ability. DNs intervened in more than two-thirds of the cases and used a variety of nursing care interventions to improve the safety of medication management. Conclusions: Preventive home visits seem to provide a unique opportunity to promote safe medication management. Several factors related to unsafe medication management were identified, and several different nursing care interventions were carried out to ensure safe medication management. Use of the SMA tool in preventive home visits seems to be advantageous in improving the safety of medication management among older persons.

Validating administrative data for the detection of adverse events in older hospitalized patients

Older hospitalized patients are at risk of experiencing adverse events including, but not limited to, hospital-acquired pressure ulcers, fall-related injuries, and adverse drug events. A significant challenge in monitoring and managing adverse events is lack of readily accessible information on their occurrence.

PURPOSE

The objective of this retrospective cross-sectional study was to validate diagnostic codes for pressure ulcers, fall-related injuries, and adverse drug events found in routinely collected administrative hospitalization data.

METHODS

All patients 65 years of age or older discharged between April 1, 2009 and March 31, 2011 from a provincial academic health sciences center in Canada were eligible for inclusion in the validation study. For each of the three types of adverse events, a random sample of 50 patients whose records were positive and 50 patients whose records were not positive for an adverse event was sought for review in the validation study (n=300 records in total). A structured health record review was performed independently by two health care providers with experience in geriatrics, both of whom were unaware of the patient's status with respect to adverse event coding. A physician reviewed 40 records (20 reviewed by each health care provider) to establish interrater agreement.

RESULTS

A total of 39 pressure ulcers, 56 fall-related injuries, and 69 adverse drug events were identified through health record review. Of these, 34 pressure ulcers, 54 fall-related injuries, and 47 adverse drug events were also identified in administrative data. Overall, the diagnostic codes for adverse events had a sensitivity and specificity exceeding 0.67 (95% confidence interval [CI]: 0.56-0.99) and 0.89 (95% CI: 0.72-0.99), respectively.

CONCLUSION

It is feasible and valid to identify pressure ulcers, fall-related injuries, and adverse drug events in older hospitalized patients using routinely collected administrative hospitalization data. The information is relatively inexpensive and easy to access with no impact on clinical staff.

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.

Aging biology and geriatric clinical pharmacology

Population aging evokes doomsday economic and sociological prognostication, despite a minority of older people suffering significant dependency and the potential for advances in therapeutics of age-related disease and primary aging. Biological aging processes are linked mechanistically to altered drug handling, altered physiological reserve, and pharmacodynamic responses. Parenteral loading doses need only be adjusted for body weight as volumes of distribution are little changed, whereas oral loading doses in some cases may require reduction to account for age-related increases in bioavailability. Age-related reduction of hepatic blood flow and hepatocyte mass and primary aging changes in hepatic sinusoidal endothelium with effects on drug transfer and oxygen delivery reduce hepatic drug clearance. Primary renal aging is evident, although renal clearance reduction in older people is predominantly disease-related and is poorly estimated by standard methods. The geriatric dosing axiom, "start low and go slow" is based on pharmacokinetic considerations and concern for adverse drug reactions, not from clinical trial data. In the absence of generalizable dosage guidelines, individualization via effect titration is required. Altered pharmacodynamics are well documented in the cardiovascular system, with changes in the autonomic system, autacoid receptors, drug receptors, and endothelial function to modify baseline cardiovascular tone and responses to stimuli such as postural change and feeding. Adverse drug reactions and polypharmacy represent major linkages to avoidable morbidity and mortality. This, combined with a deficient therapeutic evidence base, suggests that extrapolation of risk-benefit ratios from younger adults to geriatric populations is not necessarily valid. Even so, therapeutic advances generally may convert healthy longevity from an asset of fortunate individuals into a general social benefit.

The older orthopaedic patient: general considerations

People older than 65 years are more likely to need elective and emergent orthopaedic surgery compared with younger persons. They also experience significant benefits. Although age-related changes increase the risk of perioperative complications, understanding those changes allows prevention or at least early recognition and treatment when problems arise. Because of comorbidities, older persons take more medications that need to be managed in the perioperative period. Care could be simplified if patients were to bring their medications to the preoperative evaluation. Central nervous system sensitivity to certain pain medications (meperidine and propoxyphene) means that these drugs are best avoided as good alternatives exist (morphine and oxycodone). Adverse reactions to drugs are an important cause of acute confusion (delirium) that often complicates orthopaedic care. Early mobilization after surgery, avoiding certain drugs, avoiding restraints (including Foley catheters), attending to hydration, promoting normal sleep, compensating for sensory disorders, and stimulating daytime activities can prevent delirium. Patients with dementia are more likely to have delirium develop and, like many older people, will present special challenges in communication and decision making. Including family members in discussions may be helpful in ensuring truly informed consent.

Gerontology Coursework in Undergraduate Nursing Programs in the United States: A Regional Study

Because of the changing demographics, it is increasingly necessary for nurses to acquire competence in gerontology. In this article, the authors present the findings of a study investigating the extent to which undergraduate nursing programs in the United States include gerontology. Fifty-six undergraduate nursing programs in the United States were examined. In this study, course content and program curricula were examined to assess the extent to which programs include gerontological content, either integrated into other courses, or as required, stand-alone courses. The sample was randomly chosen from the Northeast, South, West and Midwest regions. All programs were accredited. More than 85% of programs evaluated did not require coursework in gerontology. The authors suggest that nurses are not being educated adequately to care for older adults.

Cost of pharmacological care of the elderly: implications for healthcare resources

Expenditures on prescribed medicines are significantly higher among those aged 65 years and over than among younger people. As populations in developed countries age so the cost of pharmacological care associated with the older population can be expected to increase. While pharmacological care represents only one component of healthcare, its costs are increasing rapidly because of advances in technology and increasing use. However, such costs should be considered within a context of decreasing disability in the elderly population, improving economic conditions among seniors and the relationship of these costs with those in other aspects of healthcare. Where medications have been demonstrated to be cost-effective, attempts to curtail expenditure growth may prove a false economy resulting in significantly higher growth elsewhere such as in the hospital and long-term care sectors. Policy responses to this issue should encompass the inclusion of elderly patients in clinical trials, the use of evidence-based principles of practice and strategies to ensure that this population obtain maximum benefit from medication through education and counselling.

Liver function and phase I drug metabolism in the elderly: a paradox

Aging is accompanied by marked changes in the physiology of many organs, as well as in their constituent cells. These nonpathological alterations in structure and/or function may affect normal physiological processes in the elderly (individuals > 65 years), for example drug disposition. The liver plays a major role in drug clearance and aging has been reported to diminish this hepatic capacity, particularly the clearance of drugs that undergo mandatory oxidation by the microsomal cytochrome P450-dependent mono-oxygenase systems. Liver volume and blood flow decline with age in humans and, no doubt, this contributes to the diminished clearance of drugs that exhibit first-pass kinetic profiles. Changes in liver morphology with aging that have been described in rodents are limited to the hepatocytes, for example accumulation of dense bodies and loss of smooth surfaced endoplasmic reticulum. There is no evidence that the increase in intracellular lipofuscin adversely affects hepatocyte functions. A number of studies have documented significant age-related declines in the amounts, specific activities and rates of induction of liver microsomal mono-oxygenases in inbred male rats. On the basis of a variety of clinical tests, most liver functions in humans appear to be well preserved. The most remarkable characteristic of liver function in the elderly is the increase in interindividual variability, a feature that may obscure age-related differences. Most in vitro studies using nonhuman primate or human liver tissue did not detect age-related deficiencies in cytochrome P450-dependent microsomal mono-oxygenases. On the other hand, there have been recent reports of age-related, but not gender-related, declines in the in vitro activities of several human liver mono-oxygenases, for example the cytochrome P450 isoform CYP3A. Nevertheless, reduced liver volume and blood flow in the elderly permit the reconciliation of: the in vivo clinical pharmacokinetic data indicative of reduced hepatic drug clearance; and the absence of significant age-related declines in the amounts or in vitro activities of liver microsomal mono-oxygenases.

Drug metabolism and drug interactions in the elderly

In the elderly concomitant use of several drugs (polypharmacy) is very common. Thus, the risk for drug interactions might be increased in this population. Since most drugs are hepatically eliminated by various metabolic pathways, liver function has to be considered as an additional factor modifying drug response. This chapter focuses on the hepatic mechanisms of interactions, especially on various inhibitors and inducers of the most important cytochrome P450 isoenzymes involved in drug metabolism. In addition, age-dependent changes in liver function are addressed. Based on pharmacokinetic results with different probe drugs, some inconsistencies in this area are discussed. The most important metabolic drug-drug interactions are independent of the age of the patients. However, since elderly patients consume a greater proportional share of drugs, they represent a population at risk for interactions. Awareness of this clinical problem may help to diminish those risks.