BRUSSELS, Belgium -- Drug prescribing for elderly patients is missing even a semblance of evidence-based guidance, constituting a worldwide public-health problem, said international researchers.
BRUSSELS, Belgium, July 13 -- Drug prescribing for elderly patients is missing even a semblance of evidence-based guidance, constituting a worldwide public-health problem, said international researchers.
A pair of reports meta-analyses, conducted by the same team and reported in the July 14 issue of The Lancet noted the many holes in the logic used for drug prescribing for elderly patients and cited inadequate physician training in geriatric pharmacotherapy.
In an effort to sort out the complexities of prescribing for these often frail or disabled patients, Anne Spinewine, Ph.D., of Universit catholique de Louvain here, and U.S. and British colleagues, examined recent randomized intervention studies aiming to offer strategies for prescribing for elderly people. Separately, they evaluated ways to manage drug interactions.
Appropriate prescribing, they said, should aim to promote the use of evidence-based therapies and keep the use of drugs for which there is no clinical need or where there is dubious efficacy to a minimum.
In the first study, dealing with appropriate prescribing, the investigators searched Medline (1970-2006), International Pharmaceutical Abstracts (1970-2006), the Cochrane Database, and additional studies, to identify, for example, appropriate or inappropriate prescribing, patient outcomes, and adverse drug reactions among patients 65 and older.
They pointed out that several factors specific to frail elderly patients, such as the use of benzodiazepines, increase the complexity of prescribing. Furthermore, clinical evidence for the effect of drugs on elderly people is scarce, goals of treatment might change, and social and economic factors might be unique to older patients.
The investigators found that aside from faulty memory and confusion, the patients themselves can influence prescribing decisions on the basis of their expectations. Contributing to the problem is physicians' inadequate training in geriatric pharmacotherapy.
They found the evidence mixed and contradictory for a link between inappropriate prescribing and adverse patient outcomes. No clear conclusions can be made about the predictive validity of specific measures, they found, except for criteria for the underuse of drugs for cardiovascular disease. They called for studies that test the predictive validity of measures of inappropriate prescribing for elderly people.
Evidence suggests that a patient's decision to take or not to take drugs might be part of a negotiation process rather than a final stance, the researchers found,, and changing patients' behavior is more likely if patients are helped to make decisions for themselves rather than being told what to do.
In the second study, including Dr. Spinewine as a co-author with a similar meta-analysis, the researchers took on the challenge of managing drug interactions in these patients, suggesting strategies for assisting in their detection, management, and prevention.
Elderly patients are at high risk of drug interactions yet the prevalence of these interactions is not well documented, they wrote. Patients frequently take many drugs, have several co-morbidities, and might not maintain adequate nutritional status.
Several types of interactions exist, they pointed out, such as drug-drug, drug-disease, drug-food, drug-alcohol, drug-herbal products, and drug-nutritional status.
Factors such as age-related changes in pharmacokinetics and pharmacodynamics, frailty, interindividual variability, reduced homeostatic mechanisms, and psychosocial issues need to be considered when drug interactions are assessed, they said.
Software can help clinicians detect drug interactions, but many programs have not been updated with the evolving knowledge of these interactions, and do not take into consideration important factors needed to optimize drug treatment in elderly patients.
Any generated recommendations have to be tempered by a holistic, geriatric, multiprofessional approach that is team-based.
Discussing the frequency pf drug interactions, the researchers noted that in a European study of 1,601 outpatients, 46% had at least one potential clinically significant drug-drug interaction, with 10% of these interactions regarded as of high severity.
Offering a simple clinical approach to managing drug interactions, the researchers listed several categories. The first category includes drug-drug interactions for drugs with a narrow therapeutic index, such a digoxin, phenytoin, or warfarin. These interactions are generally well known, have laboratory monitoring tests, and are detected by all commercial software systems.
The second category involves complex interactions, which includes patients with nine or more drugs and five or more comorbidites. Although the choice of an individual drug is usually appropriate, when considered individually, the combination can yield unwanted results.
The third category, involves cascade interactions, in which an adverse drug interaction is misinterpreted as a new medical disorder and another drug is prescribed, adding to the risk generated by a potentially unnecessary treatment.
In advice to clinicians, the researchers suggested that astute clinicians can screen any specific situation to detect drug interactions, frequently by asking the right questions.
Results suggest that elderly patients usually do better when their care is managed by a multidisciplinary geriatric team, consisting of a physician (geriatrician), nurse, and pharmacist with communication between these professionals, the investigators said.