Injuries in Adults 65 Years of Age and Older Prescribed Muscle Relaxants.

OBJECTIVE: The Beers criteria list skeletal muscle relaxants (SMR) as inappropriate for individuals 65 years of age and older because of anticholinergic effects, sedation, and risk of falls/fractures. Patients 65 years of age and older presenting to U.S. primary care clinics for injury, prescribed an SMR, are at risk for these events. SMR prescribing patterns in older adults with injury have not been well studied at the population level. Using nationally representative data, the prevalence of older adults prescribed an SMR presenting to U.S. primary care clinics with injury was examined. DESIGN: A cross-sectional study analyzing 2012 National Ambulatory Medical Care Survey (NAMCS) data using bivariate and multivariate techniques. NAMCS, a nationally representative database of the U.S. population, collects data from primary care office visits and uses a multi-stage sampling strategy. SETTING: Primary care offices throughout the United States. PATIENTS, PARTICIPANTS: Adults 65 years of age and older, presenting to rural primary care clinics with injury. MAIN OUTCOME MEASURE(S): Prescription for SMR. RESULTS: Multivariate analysis yielded that the study population presenting to rural clinics for injury had 28% greater odds, non-Caucasian adults had 11% greater odds, and those who had been seen at least twice in the past 12 months had 34% greater odds of being prescribed an SMR. Logistic regression analysis also yielded that females 65 to 74 years of age had greater odds of having a prescription for an SMR. CONCLUSION: The results of this study identified disparities among adults 65 years of age and older presenting to U.S. rural primary care clinics with injury and prescribed an SMR. Adults 65 years of age and older, Collaborative.

Polymyxin combinations: pharmacokinetics and pharmacodynamics for rationale use.

Since their reintroduction into the clinic in the 1980s, the polymyxin antibiotics colistin-administered intravenously as an inactive prodrug, colistin methanesulfonate (CMS)-and polymyxin B have assumed an important role as salvage therapy for otherwise untreatable gram-negative infections. However, the emerging pharmacodynamic and pharmacokinetic data on CMS/colistin and polymyxin B indicate that polymyxin monotherapy is unlikely to generate plasma concentrations that are reliably efficacious. Additionally, regrowth and the emergence of resistance with monotherapy are commonly reported even when concentrations exceed those achieved clinically. Given this situation, polymyxin combination therapy, which is increasingly being used clinically, has been suggested as a possible means of increasing antimicrobial activity and reducing the development of resistance. Although considerable in vitro data support this view, investigations of polymyxin combination therapy in patients have only recently commenced. The currently available clinical data for polymyxin combinations are generally limited to retrospective analyses and small, low-powered, prospective studies using traditional dosage regimens that achieve low plasma concentrations. Considering the potential for rapid development of resistance to polymyxins, well-designed clinical trials that include higher-dose polymyxin regimens are urgently required to provide a more definitive answer regarding the role of polymyxin combination therapy compared with monotherapy. In this article, we provide an overview of key in vitro and clinical investigations examining CMS/colistin and polymyxin B combination therapy.