Medication issues in older individuals with CKD

Patterns of medication use and the burden of polypharmacy in patients with chronic kidney disease: the German Chronic Kidney Disease study

Background

Patients with chronic kidney disease (CKD) bear a substantial burden of comorbidities leading to the prescription of multiple drugs and a risk of polypharmacy. However, data on medication use in this population are scarce.

Methods

A total of 5217 adults with an estimated glomerular filtration rate (eGFR) between 30 and 60 mL/min/1.73 m² or an eGFR ≥60 mL/min/1.73m² and overt proteinuria (>500 mg/day) were studied. Self-reported data on current medication use were assessed at baseline (2010-12) and after 4 years of follow-up (FU). Prevalence and risk factors associated with polypharmacy (defined as the regular use of five or more drugs per day) as well as initiation or termination of polypharmacy were evaluated using multivariable logistic regression.

Results

The prevalence of polypharmacy at baseline and FU was almost 80%, ranging from 62% in patients with CKD Stage G1 to 86% in those with CKD Stage G3b. The median number of different medications taken per day was eight (range 0-27). β-blockers, angiotensin-converting enzyme inhibitors and statins were most frequently used. Increasing CKD G stage, age and body mass index, diabetes mellitus, cardiovascular disease and a history of smoking were significantly associated with both the prevalence of polypharmacy and its maintenance during FU. Diabetes mellitus was also significantly associated with the initiation of polypharmacy [odds ratio (OR) 2.46, (95% confidence interval 1.36-4.45); P = 0.003].

Conclusion

Medication burden in CKD patients is high. Further research appears warranted to address the implications of polypharmacy, risks of drug interactions and strategies for risk reduction in this vulnerable patient population.

Awareness and knowledge among internal medicine house-staff for dose adjustment of commonly used medications in patients with CKD

Background

Drug dosing errors result in adverse patient outcomes and are more common in patients with chronic kidney disease (CKD). As internists treat the majority of patients with CKD, we study if Internal Medicine house-staff have awareness and knowledge about the correct dosage of commonly used medications for those with CKD.

Methods

A cross-sectional survey was performed and included 341 participants. The outcomes were the awareness of whether a medication needs dose adjustment in patients with CKD and whether there was knowledge for the level of glomerular filtration rate (GFR) a medication needs to be adjusted.

Results

The overall pattern for all post-graduate year (PGY) groups in all medication classes was a lack of awareness and knowledge. For awareness, there were statistically significant increased mean differences for PGY2 and PGY3 as compared to PGY1 for allergy, endocrine, gastrointestinal, and rheumatologic medication classes but not for analgesic, cardiovascular, and neuropsychotropic medication classes. For knowledge, there were statistically significant increased mean differences for PGY2 and PGY3 as compared to PGY1 for allergy, cardiovascular, endocrine, and gastrointestinal, medication classes but not for analgesic, neuropsychotropic, and rheumatologic medication classes.

Conclusions

Internal Medicine house-staff across all levels of training demonstrated poor awareness and knowledge for many medication classes in CKD patients. Internal Medicine house-staff should receive more nephrology exposure and formal didactic educational training during residency to better manage complex treatment regimens and prevent medication dosing errors.

The Elderly are Different: Initiating Dialysis in Frail Geriatric Patients

Decisions and discussions about the initiation of dialysis in the elderly are often challenging because of the high prevalence of comorbidities and frailty in this population. Mortality is high, functional decline is likely, and quality of life tends to be lower in the elderly on dialysis. It is thus important to counsel these patients on the risks, benefits, and burdens of dialysis to assist them in making an informed choice that is in line with their goals, preferences, and expectations. For some patients, dialysis may be a desirable choice. For others, the alternative of palliative care may provide a more favorable balance of benefits versus burdens. Elderly patients who choose to proceed with dialysis often benefit from an interdisciplinary team that helps to manage and monitor their health status, while maximizing the benefits of treatment and decreasing its potential harms. These goals can be promoted by effective communication and through individualized decisions about vascular access, medication choices, and dietary limitations. Finally, close monitoring of functional status will help to determine whether dialysis remains in a patient's best interest and when alternatives should be offered.

Glomerular filtration rate in the elderly and in the oldest old: correlation with frailty and mortality

The equations for estimating kidney function have become very popular in the last decade. However, the clinical and prognostic meaning of these measures may be very different in older populations. Two cohorts of people aged 65-89 years (older sample) and 90 or more (oldest old sample) were used to investigate the prognostic significance of estimated glomerular filtration rate (eGFR). Additionally, we also investigated whether combining frailty and eGFR may improve the accuracy of frailty in predicting mortality. We found that lower eGFR values were significantly more frequent among frail subjects in both groups. eGFR < 30 was associated with increased risk for all-cause mortality either in subjects aged 65-89 years (HR = 3.71, 95% CI = 1.23-11.2) or in those aged 90 or more (HR = 1.53, 95% CI = 1.05-2.23). In the latter group, a not significant trend for increasing mortality was also observed among people with eGFR > 60 (HR = 1.28, 95% CI = 0.72-2.26). In addition, the oldest old subjects with eGFR > 60 and eGFR < 30 had the lowest hand-grip strength and ADL values. Combining eGFR and frailty status significantly improved the accuracy of frailty in predicting mortality only in the older sample. In conclusion, a U-shaped relationship exists between eGFR and mortality in the oldest old, but not in older individuals. Our findings suggest that eGFR needs to be adjusted for muscle mass/physical performance when estimating kidney function in people aged 90 or more. Nevertheless, in subjects aged 65-89 years, eGFR may improve the accuracy of frailty status in predicting prognosis, thus suggesting that eGFR may represent an additional dimension of frailty syndrome.

Drug-drug interactions between sucroferric oxyhydroxide and losartan, furosemide, omeprazole, digoxin and warfarin in healthy subjects

Background

The novel iron-based phosphate binder sucroferric oxyhydroxide is being investigated for the treatment of hyperphosphatemia. Patients with chronic kidney disease often have multiple comorbidities that may necessitate the daily use of several types of medication. Therefore, the potential pharmacokinetic drug–drug interactions between sucroferric oxyhydroxide and selected drugs commonly taken by dialysis patients were investigated.

Methods

Five Phase I, single-center, open-label, randomized, three-period crossover studies in healthy volunteers investigated the effect of a single dose of sucroferric oxyhydroxide 1 g (based on iron content) on the pharmacokinetics of losartan 100 mg, furosemide 40 mg, omeprazole 40 mg, digoxin 0.5 mg and warfarin 10 mg. Pharmacokinetic parameters [including area under the plasma concentration–time curve (AUC) from time 0 extrapolated to infinite time (AUC_0–∞) and from 0 to 24 h (AUC_0–24)] for these drugs were determined: alone in the presence of food; with sucroferric oxyhydroxide in the presence of food; 2 h after food and sucroferric oxyhydroxide administration.

Results

Systemic exposure based on AUC_0–∞ for all drugs, and AUC_0–24 for all drugs except omeprazole (for which AUC 0–8 h was measured), was unaffected to a clinically significant extent by the presence of sucroferric oxyhydroxide, irrespective of whether sucroferric oxyhydroxide was administered with the drug or 2 h earlier.

Conclusions

There is a low risk of drug–drug interactions between sucroferric oxyhydroxide and losartan, furosemide, digoxin and warfarin. There is also a low risk of drug–drug interaction with omeprazole (based on AUC_0–∞ values). Therefore, sucroferric oxyhydroxide may be administered concomitantly without the need to adjust the dosage regimens of these drugs.

Polypharmacy and food-drug interactions among older persons: a review

Polypharmacy is generally defined as the use of 5 or more prescription medications on a regular basis. The average number of prescribed and over-the-counter medications used by community-dwelling older adults per day in the United States is 6 medications, and the number used by institutionalized older persons is 9 medications. Almost all medications affect nutriture, either directly or indirectly, and nutriture affects drug disposition and effect. This review will highlight the issues surrounding polypharmacy, food-drug interactions, and the consequences of these interactions for the older adult.

Confounding and control of confounding in nonexperimental studies of medications in patients with CKD

Confounding is an important source of bias in nonexperimental studies, arising when the effect of an exposure on the occurrence of an outcome is distorted by the effect of some other factor. In nonexperimental studies of patients with CKD or who are on chronic dialysis, confounding is a significant concern owing to the high burden of comorbid disease, extent of required clinical management, and high frequency of adverse clinical events in this patient population. Confounding can be addressed in both the design stage (restriction, accurate measurement of confounders) and analysis stage (stratification, multivariable adjustment, propensity scores, marginal structural models, instrumental variable) of a study. Time-dependent confounding and confounding by indication are 2 special cases of confounding that can arise in studies of treatment effects and may require more sophisticated analytic techniques to adequately address. The availability and expanded use of large health care databases have ensured greater precision and have now placed the focus on validity. Addressing the major threats to validity, such as confounding, should be a first-order concern.

Factors associated with potentially preventable hospitalization among nursing home residents in New York State with chronic kidney disease

OBJECTIVE

Identify clinical and organizational factors associated with potentially preventable ambulatory care sensitive (ACS) hospitalization among nursing home residents with chronic kidney disease.

METHODS

New York State Nursing home residents (n = 5449) age 60+ with chronic kidney disease and were hospitalized in 2007. Data included residents' sociodemographic and clinical characteristics, nursing home organizational factors, and ACS hospitalizations. Multivariate logistic regression quantified the association between potential determinants and ACS hospitalizations (yes versus no).

RESULTS

Prevalence of chronic kidney disease among nursing home residents is 24%. Potentially avoidable ACS hospitalization among older nursing home residents with chronic kidney disease is 27%. Three potentially modifiable factors associated with significantly higher odds of ACS hospitalization include the following: presence of congestive heart failure (OR = 1.4; 95% CI 1.24-1.65), excessive medication use (OR = 1.3; 95% CI 1.11-1.48), and the lack of training provided to nursing staff on how to communicate effectively with physician about the resident's condition. (OR = 1.3; 95% CI 0.59-0.96).

CONCLUSION

To reduce potentially preventable ACS hospitalization among chronic kidney disease patients, congestive heart failure and excessive medication use can be kept stable using relatively simple interventions by periodic multidisciplinary review of medications and assessing appropriate response to therapy; and communication training be provided to nursing staff on how to articulate to the responsible physician important changes in the patients' condition.