Drug therapy in haemodialysis patients. Special considerations in the elderly

Drug-Induced Nephrotoxicity and Dose Adjustment Recommendations: Agreement Among Four Drug Information Sources

Hospitalized patients require the use of a variety of drugs, many of which individually or in combination have the potential to cause kidney damage. The use of potentially nephrotoxic drugs is often unavoidable, and the need for dose adjustment should be evaluated. This study is aimed at assessing concordance in information on drug-induced nephrotoxicity and dose adjustment recommendations by comparing four drug information sources (DRUGDEX^®, UpToDate^®, Medscape^® and the Brazilian Therapeutic Formulary) using the formulary of a Brazilian public hospital. A total of 218 drugs were investigated. The global Fleiss’ kappa coefficient was 0.265 for nephrotoxicity (p < 0.001; CI 95%, 0.211–0.319) and 0.346 for recommendations (p < 0.001; CI 95%, 0.292–0.401), indicating fair concordance among the sources. Anti-infectives and anti-hypertensives were the main drugs cited as nephrotoxic by the different sources. There were no clear definitions for qualitative data or quantitative values for dose adjustments among the four information sources. There was no advice for dosing for a large number of the drugs in the international databases. The National Therapeutic Formulary offered imprecise dose adjustment recommendations for many nephrotoxic drugs. Discrepancies among information sources may have a clinical impact on patient care and contribute to drug-related morbidity and mortality.

Health-related quality of life in dialysis patients with constipation: a cross-sectional study

OBJECTIVES

To evaluate differences in the health-related quality of life (HRQoL) between patients with constipation receiving hemodialysis (HD) and those receiving peritoneal dialysis (PD).

METHODS

In this cross-sectional study, 605 dialysis patients (478 HD cases and 127 PD cases; all patients were older than 18 years) from our hospital were included. A questionnaire was used to evaluate their constipation statuses. The effect of constipation on HRQoL was assessed, using the Chinese version of the 12-item short-form (SF-12) general health survey. Karnofsky score, sociodemographic, and clinical data were also collected. We performed multiple logistic regression analysis to define independent risk factors for constipation and impaired HRQoL.

RESULTS

A total of 605 participants (326 men [53.9%] and 279 women [46.1%]) were surveyed. The incidence of constipation was 71.7% in HD patients and 14.2% in PD patients. Dialysis patients with constipation had significantly lower mean SF-12 Physical Component Summary scale and Mental Component Summary scale scores than the nonconstipation group (P < 0.05), whereas HD patients had better SF-12 Physical Component Summary and Mental Component Summary scores than PD patients (P < 0.05). When we performed multivariate logistic regression analysis, dialysis modality, diabetes, and the number of constipation-related medications were three independent risk factors associated with constipation. As for impaired HRQoL in the constipated dialysis population, dialysis modality was found to be another independent risk factor in addition to age and diabetes.

CONCLUSION

PD patients with constipation had worse HRQoL than HD control participants. We should pay more attention to the patients with constipation receiving PD, as peritonitis caused by constipation was associated with a higher mortality.

Quality of health care for older women: What do we know?

As the proportion of the population age 65 and over continues to grow--to a projected 20.5% or 77.2 million by the year 2040--tracking the quality, access, and receipt of care for older women becomes more important, since the majority of older citizens are women. This article establishes a rough baseline for the quality of care, primarily preventive care, received by older women compared to older men, using selected measures and data of the 2004 National Healthcare Quality Report and National Healthcare Disparities Report. It highlights significant differences between women and men, as well as differences for racial, ethnic, and educational subgroups. Generally, older non-Hispanic white women frequently score higher than their Hispanic and non-Hispanic black counterparts, and more educated women often score significantly higher than their less-educated peers on several measures of quality of care. Compared to their male counterparts, older women are significantly less likely to have any colorectal screening test, to keep high blood pressure under control, and to receive aspirin or beta-blockers upon hospital admission or discharge for acute myocardial infarction. Results are mixed for the process measures related to diabetes, but improvements are clearly needed toward increased rates of eye and foot examinations. Rates of influenza and pneumococcal vaccinations are low but can be improved through Medicare-covered services. We also found that older women are screened less often for breast cancer than those ages 40 to 64. There is still a pervasive lack of knowledge in the research and clinical communities about the unique health care needs of and appropriate processes of care for older adults. More research needs to focus on the quality of care for this growing population in order to allow the development of geriatric-based quality measures and models of care that will set the standards of healthcare for older adults in general, and older women in particular.

Drug Therapy in Transplant Recipients

Elderly patients with end-stage organ failure are now more frequently undergoing transplantation. Medication management in this population is challenging because of the combination of multiple comorbidities, polypharmacy, and immunological, pharmacokinetic and pharmacodynamic changes attributable to the aging process. Immunosuppressive medications can exacerbate pre-existing medical conditions and promote the development of disease processes. Cardiovascular disorders, such as hypertension, coronary artery disease, congestive heart failure and arrhythmias are common in elderly transplant recipients, and account for most of the deaths in this population. Blood pressure, blood glucose and cholesterol control is of particular concern because elderly transplant recipients frequently have or develop these complications. Elderly transplant recipients are commonly receiving anticoagulation therapy with warfarin and are at a higher risk of bleeding, especially if they have renal dysfunction. Infectious complications occur frequently in the transplanted population, with pneumonia being the most common infection seen in hospitalised patients. Attention to vaccination for the prevention of influenza and pneumococcal infections is important because of the increased risk of these diseases in this population. Depression itself has been associated with decreased survival in older individuals, and depression in elderly transplant recipients may be reversible with the administration of pharmacological agents. Effective long-term care of transplant recipients demands an understanding of how particular medications affect clinical evaluation and treatment. This article addresses some of the practical issues surrounding medication management and prevention of these particular problems in elderly transplant recipients.

The comparison of antibody response to influenza vaccination in continuous ambulatory peritoneal dialysis, hemodialysis and renal transplantation patients

BACKGROUND

The immune system in renal transplant (Tx), Continuous Ambulatory Peritoneal Dialysis (CAPD) and hemodialysis (HD) patients have been suppressed and antibody response to vaccination is weaker than that of the normal population. Additionally immune response to vaccination also differs from each other in aforementioned three groups resulting from different levels immunosuppression. In the present study, detection of antibody response to influenza vaccine as an indicator of the level of immunity in Tx, CAPD and HD patients was aimed

PATIENTS AND METHODS

Forty-eight patients (17 Tx, 16 CAPD and 15 HD) and 10 healthy adults, as a control group were enrolled into the study. Purified, split-virus, commercial trivalent influenza vaccine (VAXIGRIP--Pasteur Merieux Connaught, single dose of 0.5 ml into the deltoid muscle) containing 15 microg of each hemagglutinin of A/Johannesburg/82/96 (H1N1), A/Nachang/933/95 (H3N2) and B/Harbin/07/94 (B) strains were administered to all subjects. Serum samples were collected before and 1 month after vaccination to determine antibody titers. Hemagglutination-inhibition test (HI) was applied for determination of antibody response. The antibody response against each strain was measured separately. In addition to measurement of antibody response, increments in antibody titer (n-fold increase in titer), proportion of patients with protective antibody levels and seroconversion levels were taken into account. Wilcoxon paired 2 test and Mann-Whitney U test were applied for statistical analysis. p < 0.05 was accepted as significance level.

RESULTS

Significant increases in antibody titers for all three antigens were observed in the study groups after vaccination (p = 0.001). However, the increase in titer of H3N2 was lower in Tx, CAPD and HD patients than that of the control group (1.0-2.0 vs 5.00) (p = 0.01). The proportion of protective antibody titers and seroconvertions were increased after vaccination in all subjects. Proportions of patients with protective antibody titers after vaccination were lower in Tx, CAPD and HD groups in comparison to control group.

CONCLUSION

Although antibody titers in Tx, CAPD and HD patients presented significant increases after vaccination, the proportions of patients with protective antibody titers were lower in comparison to control group. Tx, CAPD and HD patients should be vaccinated every year to be able avoid potential morbidity and mortality of the influenza infection. Trial of high dose vaccination protocols may be useful to increase the proportion of patients with protective antibody levels.

Probiotics and prebiotics: A brief overview

Probiotics and prebiotics are 2 food ingredients that confer physiologic effects through the gastrointestinal tract. Probiotics have been defined as viable microorganisms that (when ingested) have a beneficial effect in the prevention and treatment of specific pathologic conditions. These microorganisms are believed to exert biological effects through a phenomenon known as colonization resistance, whereby the indigenous anaerobic flora limits the concentration of potentially pathogenic (mostly aerobic) flora in the digestive tract. Other modes of action, such as supplying enzymes or influencing enzyme activity in the gastrointestinal tract, may also account for some of the other physiologic effects that have been attributed to probiotics. Conversely, prebiotics are nondigestible food ingredients that beneficially affect host health by selectively stimulating the growth and/or activity of 1 or a limited number of bacteria in the colon. The prebiotic, fructooligosaccharide (FOS), is found naturally in many foods, such as wheat, onions, bananas, honey, garlic, or leeks. They can also be isolated from chicory root or synthesized enzymatically from sucrose. Fermentation of FOS in the colon results in a large number of physiologic effects including increasing the numbers of bifidobacteria in the colon, increasing calcium absorption, increasing fecal weight, shortening of gastrointestinal transit time, and possibly lowering blood lipid levels. Other effects that have been observed in animal models include an increase in cecal weight and an increase in fecal nitrogen excretion. The increase in bifidobacteria has been assumed to benefit human health by producing compounds to inhibit potential pathogens, by reducing blood ammonia levels, and by producing vitamins and digestive enzymes.

Special clinical problems in geriatric patients

The elderly dialysis patient presents several challenges to the nephrologist. Concurrent illnesses may complicate management, disabilities may interfere with mobility, hearing, and vision, and depression and mental incompetence may be present. For these reasons the physician and health care team should adopt a broad treatment plan, using expert help if needed in managing the patient and involving family members, clergy, and friends. While lifestyle changes are inevitable for the elderly with initiation of dialysis, satisfactory outcomes are possible. In the event of overwhelming illness and the patient's perception of the futility of continuation of dialysis, cessation of dialysis must be approached in a humane, considerate, and compassionate manner.

Implications for the role of endogenous nitric oxide inhibitors in hemodialysis hypotension

Hypotensive episodes during hemodialysis in patients with end-stage renal disease in the absence of inadequate maintenance of the plasma volume, pre-existence of cardiovascular disease, or autonomic nervous system dysfunction is accompanied by increase in the plasma concentrations of the end-products of nitric oxide metabolism, above the levels expected based on the reduction of urea. Factors that can influence the synthesis of nitric oxide or the regulation of the effects of this free radical in patients with chronic renal failure are reviewed. Convergence of these factors and their interactions during the hemodialysis procedure are discussed as the basis for the generation of excessive amounts of nitric oxide that serves as an important contributing factor in the development of symptomatic hypotension.

Use of isomalto-oligosaccharide in the treatment of lipid profiles and constipation in hemodialysis patients

Chronic constipation and hyperlipidemia, one of the many atherogenic risk factors, were common complications in hemodialysis (HD) patients. The present trial evaluates the therapeutic efficacy of isomaltose-oligosaccharide (IMO) in the treatment of chronic severe constipation and its effect on lipid profiles in 20 HD patients. After a 2-week basal period, these patients were allocated to receive 30 g of IMO for a 4-week period. After the study period, these patients were observed for another 4 weeks. Bowel frequency, gastrointestinal symptomatology, biochemical parameters, and lipid profiles were assessed. All patients completed this study. IMO induced a significant increase in number of bowel movements and hence improvement of constipation in 76.3% + 30.9% of patients during the 4-week treatment. Some, but well-tolerated gastrointestinal side effects were noted. Statistically significant decreases in total cholesterol and triglycerides (TG) and increases in high density lipoprotein-cholesterol (HDL-C) were noted after IMO treatment (P <.05 compared with baseline and controls). After the study period, those patients receiving IMO had reductions in levels of total cholesterol -17.6%, TG -18.4%, and elevations of levels of HDL-C by +39.1%. In conclusion, IMO once a day is well tolerated and effective in increasing bowel frequency and improving constipation in HD patients. In addition, IMO treatment was effective in lowering total cholesterol and triglycerides and in raising HDL-C in HD patients.