Potential drug interactions during a three-decade study period: a cross-sectional study of a prescription register
ABSTRACT The increased risk of adverse events in patients receiving potentially interacting drugs has long been recognized. The purpose of the present study was to evaluate the change in the risk of receiving potentially interacting drugs during a period covering three decades and to examine the relative risk of actual drug combinations.
The prescriptions from all individuals (about 8,000) with two or more prescriptions during three periods of 15 months, October to December 1983-1984, 1993-1994 and 2003-2004, were collected from an ongoing cohort study in the county of Jämtland, Sweden. The potential interactions were detected by a computerized system.
The relative risk (RR) of receiving potentially interacting drugs increased for type C interactions [RR: 1.177, 95% confidence interval (CI): 1.104-1.256] and decreased for type D interactions (RR: 0.714, 95% CI: 0.587-0.868) from the period 1983-1984 to 2003-2004. Polypharmacy for the participants increased by 61%, from 9.05 filled prescriptions per subject in 1983-1984 to 10.6 in 1993-1994 and 14.6 in 2003-2004. The RR was positively correlated to the pronounced increase in polypharmacy; in addition, an exponential relationship was found for the more severe type D interactions. Few interacting drug combinations were responsible for a large proportion of the risk.
We conclude that the risk of receiving potentially interacting drugs was strongly correlated to the concomitant use of multiple drugs. The pronounced increase in polypharmacy over time implies a growing reason for prescribers and pharmacists to be aware of drug interactions. Recently established national prescription registers should be evaluated for drug interaction vigilance, both clinically and epidemiologically.
[Show abstract] [Hide abstract]
ABSTRACT: To examine associations between polypharmacy and delirium diagnosed in elderly patients hospitalized in geriatric acute care unit after emergency hospital admission. Study design was an observational cohort study in the acute geriatric care unit of a university hospital. We included 410 consecutive patients admitted to the acute geriatric ward during 9 months. Within 72 hours of each patient's hospitalization, a clinically trained geriatrician collected the following data: sociodemographic details (age, sex, type of residence), predisposing factors for delirium, main cause of hospitalization, and current medications. Polypharmacy was defined as 6 or more drugs a day. Delirium was assessed by a geriatrician using the Confusion Assessment Method and was diagnosed on the basis of clinical history with an acute change in usual functional status, behavioral observation, and clinical and cognitive assessment. Nearly 25% of hospitalized patients had delirium. The Confusion Assessment Method was positive in 69% of patients receiving polypharmacy and in 30% of those not receiving polypharmacy, a relative risk of 2.33. The proportion of elderly patients receiving polypharmacy was 58.53%. In our study, polypharmacy is an independent risk factor for delirium in a population of elderly patients after emergency admission. In the geriatric population, delirium is an underestimated scourge and because of its medicosocial and economic consequences and its impact on morbidity and mortality, we need to give increased attention to the prevention and control of polypharmacy, which is a predisposing factor for delirium.Journal of the American Medical Directors Association 11/2014; 15(11):850.e11-5. DOI:10.1016/j.jamda.2014.08.012 · 4.78 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Medication is an essential part of health care and enables the prevention and treatment of many conditions. However, medication errors and drug-related problems (DRP) are frequent and cause suffering for patients and substantial costs for society. eMedication, defined as information technology (IT) in the medication management process, has the potential to increase quality, efficiency and safety but can also cause new problems and risks. In this thesis, we have studied the employment of IT in different steps of the medication management process with a focus on the user's perspective. Sweden is one of the leading countries when it comes to ePrescribing, i.e. prescriptions transferred and stored electronically. We found that ePrescribing is well accepted and appreciated by pharmacists (Study I) and patients (Study II), but that there was a need for improvement in several aspects. When the pharmacy market in Sweden was re-regulated, four new dispensing systems were developed and implemented. Soon after the implementation, we found weaknesses related to reliability, functionality, and usability, which could affect patient safety (Study III). In the last decade, several county councils in Sweden have implemented shared medication lists within the respective region. We found that physicians perceived that a regionally shared medication list generally was more complete but often not accurate (Study IV). Electronic expert support (EES) is a decision support system which analyses patients´ electronically-stored prescriptions in order to detect potential DRP, i.e. drug-drug interactions, therapy duplication, high dose, and inappropriate drugs for geriatric or pediatric patients. We found that EES detected potential DRP in most patients with multi-dose drug dispensing in Sweden (Study V), and that the majority of alerts were regarded as clinically relevant (Study VI). For an improved eMedication, we need a holistic approach that combines technology, users, and organization in implementation and evaluation. The thesis suggests a need for improved sharing of information and support for decision making, coordination, and education, as well as clarification of responsibilities among involved actors in order to employ appropriate IT. We suggest collaborative strategic work and that the relevant authorities establish guidelines and requirements for IT in the medication management process.10/2014, Degree: Doctoral dissertation, Supervisor: Göran Petersson