American Journal Geriatric Pharmacotherapy最新文献

Background

Most elderly patients with type 2 diabetes require, or will eventually require, insulin to achieve or maintain their glycemic goals. However, insulin therapy remains underused in this population.

Objective

The goal of this review is to evaluate the role of insulin therapy in elderly patients and identify strategies to improve its use in this patient population.

Methods

Searches of the MEDLINE and EMBASE databases were conducted to identify papers published in English between January 1990 and March 2010. The following search terms were used: diabetes mellitus, insulin, elderly, geriatric, analog, premix, pen device, and human insulin. Papers selected for review included meta-analyses, randomized controlled trials of insulin therapy, or evidence-based reviews and/or expert opinion regarding the use of insulin in elderly patients with diabetes.

Results

Insulin therapy is the most effective antidiabetic agent when appropriately dosed; however, only a minority of elderly patients with diabetes uses it. Although there are few randomized controlled studies on insulin use in the elderly, an individualized approach to insulin therapy is recommended to account for varying clinical and practical factors that affect diabetes care in this patient population. Therapy with insulin analogs offers several advantages compared with human insulin regimens, including a more physiologic pharmacologic profile, increased convenience, and a reduced risk of hypoglycemia, which may make them particularly attractive in older adults. Premixed insulin analog therapy may provide added convenience, as well as improved glycemic control. Insulin pen devices are also recommended to facilitate insulin dosing and help patients maintain their independence.

Conclusions

The improved clinical profiles of insulin analogs and the ease of use of newer insulin delivery devices may be advantageous in elderly patients with diabetes; however, additional research on the efficacy and safety of insulin regimens is urgently needed.

Objectives

The objectives of this study were to describe changes in glyburide prescribing in cohorts that were and were not targeted by a risk reduction project, assess factors associated with glyburide discontinuation, and evaluate changes in glycated hemoglobin (ie, HbA_1c) levels and rates of serious hypoglycemia.

Methods

This historical cohort study included a targeted cohort of 4368 outpatient veterans aged ≥65 years with active prescriptions for glyburide between April 1, 2007 and June 30, 2007 and serum creatinine (SCr) ≥2 mg/dL and a nontargeted cohort of 1886 outpatients meeting these same criteria between July 1, 2007 and September 3, 2007. The intervention in the risk reduction project took place on September 4, 2007 and entailed giving regional pharmacy leaders information about the increased risk of hypoglycemia with glyburide and the list of targeted patients for follow up with providers. For each patient, the study period was the time between the date they first met the eligibility criteria and March 31, 2008. All data were obtained from Veterans Affairs (VA) administrative databases. The primary outcome was the discontinuation of glyburide. Secondary outcomes were the change in HbA_1c after stopping glyburide and the rate of serious hypoglycemia after intervention.

Results

Incidence rate ratios (IRRs) for glyburide discontinuation in targeted versus nontargeted cohorts were statistically significantly elevated in September (IRR 2.1; 95% CI 1.7–2.5), October (IRR 1.3; 95% CI 1.1–1.6), and November 2007 (IRR 1.4; 95% CI 1.1–1.7). The intervention, black race, SCr, Charlson comorbidity score, new glyburide use, and VA region were independently associated with discontinuation. Among patients in the targeted cohort who discontinued glyburide, mean (SD) HbA_1c at baseline and after discontinuation were 7.17% (1.35%), and 7.22% (1.34%), respectively (P = 0.36). The hypoglycemia rates/1000 person-days were 0.093 before the intervention and 0.070 afterwards (P = 0.10).

Conclusion

A one-time intervention in a risk reduction project decreased glyburide use over a 3-month period in elderly outpatients with renal insufficiency without compromising glucose control.

Background

Medication nonadherence is a common problem among the elderly.

Objective

To conduct a systematic review of the published literature describing potential nonfinancial barriers to medication adherence among the elderly.

Methods

The PubMed and PsychINFO databases were searched for articles published in English between January 1998 and January 2010 that (1) described “predictors,” “facilitators,” or “determinants” of medication adherence or that (2) examined the “relationship” between a specific barrier and adherence for elderly patients (ie, ≥65 years of age) in the United States. A manual search of the reference lists of identified articles and the authors' files and recent review articles was conducted. The search included articles that (1) reviewed specific barriers to medication adherence and did not solely describe nonmodifiable predictors of adherence (eg, demographics, marital status), (2) were not interventions designed to address adherence, (3) defined adherence or compliance and specified its method of measurement, and (4) involved US participants only. Nonsystematic reviews were excluded, as were studies that focused specifically on people who were homeless or substance abusers, or patients with psychotic disorders, tuberculosis, or HIV infection, because of the unique circumstances that surround medication adherence for each of these populations.

Results

Nine studies met inclusion criteria for this review. Four studies used pharmacy records or claims data to assess adherence, 2 studies used pill count or electronic monitoring, and 3 studies used other methods to assess adherence. Substantial heterogeneity existed among the populations studied as well as among the measures of adherence, barriers addressed, and significant findings. Some potential barriers (ie, factors associated with nonadherence) were identified from the studies, including patient-related factors such as disease-related knowledge, health literacy, and cognitive function; drug-related factors such as adverse effects and polypharmacy; and other factors including the patient-provider relationship and various logistical barriers to obtaining medications. None of the reviewed studies examined primary nonadherence or nonpersistence.

Conclusion

Medication nonadherence in the elderly is not well described in the literature, despite being a major cause of morbidity, and thus it is difficult to draw a systematic conclusion on potential barriers based on the current literature. Future research should focus on standardizing medication adherence measurements among the elderly to gain a better understanding of this important issue.

Background

Older diabetic patients are at increased risk for skin infections, often with methicillin-resistant Staphylococcus aureus (MRSA). Linezolid offers oral therapy with MRSA coverage. We present a case of linezolid-associated hypoglycemia in a 64-year-old diabetic patient with presumed MRSA cellulitis.

Case summary

A 64-year-old man with diabetes was treated for cellulitis. Linezolid was started when amoxicillin/clavulanate failed. Within 7 days, he developed frequent diaphoresis and tremulousness, with glucoses of 30 to 60 mg/dL. Hypoglycemia worsened despite decreasing insulin use, discontinuing glyburide, and increasing caloric intake. The day of admission, he awoke with a glucose level of 30 mg/dL. He took no medications, ate a large breakfast, and presented to clinic. He was symptomatic with a glucose level of 35 mg/dL. Hypoglycemia persisted despite IV dextrose. Linezolid was discontinued immediately in favor of vancomycin. Dextrose was weaned and his diabetes medications were resumed without further hypoglycemia.

Conclusions

Linezolid has monoamine oxidase (MAO) inhibitory properties, and MAO inhibitors have been reported to contribute to hypoglycemia. The use of linezolid in older diabetic patients, especially those patients already taking agents with the potential to cause hypoglycemia, represents an area of concern. Increased comorbidities and polypharmacy in geriatric patients adds to this concern.

Background

Older adults are susceptible to a variety of illnesses, many of which can be treated with medications that may need to be used for the long term. Considerable attention has been paid to drugs that, in addition to their intended function, may have an anticholinergic effect that results in undesirable side effects, including impairment in cognition. Cholinesterase inhibitors are used as procholinergic drugs to improve cognitive dysfunction in Alzheimer's disease. We hypothesized that some of the drugs commonly used by older adults might, in addition to their intended function, also have procholinergic effects by virtue of inhibiting cholinesterases.

Objective

To determine the potential procholinergic nature of some of the commonly used drugs by examining their cholinesterase inhibiting properties.

Methods

The Ellman spectrophotometric method was used with human acetylcholinesterase and butyrylcholinesterase, in the absence and presence of increasing concentrations of each test drug. To compare inhibition potencies, from enzyme kinetic data, we determined half maximal inhibitory concentration (IC₅₀ values) for each cholinesterase by each drug.

Results

Of the 28 drugs examined, over half (17/28) inhibited one or both of the human cholinesterases. The inhibition potencies were often within 1 to 2 orders of magnitude of reversible cholinesterase inhibitors currently used to treat Alzheimer's disease. These included trazodone, quetiapine, risperidone, indapamide, and perindopril.

Conclusions

Many drugs used by older adults for other reasons have potentially clinically relevant procholinergic effects. The effect of cumulative cholinesterase inhibition merits clinical evaluation.

Background: Most studies of potentially inappropriate medication (PIM) use among older adults have focused on prevalence rather than incidence.

Objectives: The goals of this study were to determine the 1-year incidence of PIM use among elderly Indiana Medicaid residents of nursing homes and to examine associations between incident PIM use and hospitalization and mortality.

Methods: A retrospective analysis was conducted using Indiana Medicaid enrollment and administrative claims files. Individuals were included if they were Medicaid eligible and aged ≥65 years as of January 2003 and received nursing home services in each month of 2003 or until death in 2003. Individuals also had to receive nursing home services from October 2002 through December 2002 for inclusion in the sample. To focus analysis on incident PIM use, individuals who received any PIM prescription medication from October 2002 through December 2002 were excluded from the sample, as were those not prescribed any new medication in 2003. PIMs were identified using the 2003 Beers criteria. Associations between incident PIM use and hospitalization and mortality were assessed using logistic regression models after controlling for other risk factors. Potential selection bias was examined using bivariate probit models.

Results: The study sample consisted of 7594 individuals (mean age, 83.07 years). A majority of the sample was female (76.5%), white (89.7%), and widowed (58.8%). Most individuals received care in nursing homes located in urban areas (5306 [69.9%]) and in the central region of Indiana (2838 [37.4%]). One-year incidence of PIM use was 42.1%. Incident PIM users were more likely to be hospitalized (odds ratio [OR] = 1.27; 95% CI, 1.10–C1.46) and more likely to die (OR = 1.46; 95% CI, 1.31–C1.62) in the 12 months after first receiving a PIM than nonusers, even after adjusting for demographic and clinical risk factors.

Conclusions: Incident PIM use was high among these elderly Indiana Medicaid residents of nursing homes. Individuals who began use of a PIM were at a higher risk of hospitalization and of dying.