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.
- SourceAvailable from: Tora Hammar[Show abstract] [Hide abstract]
ABSTRACT: Background Drug related problems (DRPs) are frequent and cause suffering for patients and substantial costs for society. Multi-dose drug dispensing (MDDD) is a service by which patients receive their medication packed in bags with one unit for each dose occasion. The clinical decision support system (CDSS) electronic expert support (EES) analyses patients' prescriptions in the Swedish national e-prescription repository and provides alerts if potential DRPs are detected, i.e. drug-drug interactions, duplicate therapy, drug-disease contraindications, high dose, gender warnings, geriatric, and paediatric alerts. Objective To analyse potential DRPs in patients with MDDD, detected by means of EES. Setting A register study of all electronically stored prescriptions for patients with MDDD in Sweden (n = 180,059) March 5-June 5, 2013. Method Drug use and potential DRPs detected in the study population during the 3 month study period by EES were analysed. The potential DRPs were analysed in relation to patients' age, gender, number of drugs, and type of medication. Main outcome measure Prevalence of potential DRPs measured as EES alerts. Results The study population was on average 75.8 years of age (±17.5, range 1-110) and had 10.0 different medications (±4.7, range 1-53). EES alerted for potential DRPs in 76 % of the population with a mean of 2.2 alerts per patient (±2.4, range 0-27). The older patients received a lower number of alerts compared to younger patients despite having a higher number of drugs. The most frequent alert categories were drug-drug interactions (37 % of all alerts), duplicate therapy (30 %), and geriatric warnings for high dose or inappropriate drugs (23 %). Psycholeptics, psychoanaleptics, antithrombotic agents, anti-epileptics, renin-angiotensin system agents, and analgesics represented 71 % of all drugs involved in alerts. Conclusions EES detected potential DRPs in the majority of patients with MDDD. The number of potential DRPs was associated with the number of drugs, age, gender, and type of medication. A CDSS such as EES might be a useful tool for physicians and pharmacists to assist in the important task of monitoring patients with MDDD for potential DRPs.International Journal of Clinical Pharmacy 06/2014; · 1.25 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Drug-drug interactions (DDIs) are an important type of adverse drug events. Yet overall incidence and pattern of DDIs in Iran has not been well documented and little information is available about the strategies that have been used for their prevention. The purpose of this study was to systematically review the literature on the incidence and pattern of DDIs in Iran as well as the used strategies for their prevention. PubMed, Scopus, electronic Persian databases, and Google Scholar were searched to identify published studies on DDIs in Iran. Additionally, the reference lists of all retrieved articles were reviewed to identify additional relevant articles. Eligible studies were those that analyzed original data on the incidence of DDIs in inpatient or outpatient settings in Iran. Articles about one specific DDI and drug interactions with herbs, diseases, and nutrients were excluded. The quality of included studies was assessed using quality assessment criteria. Database searches yielded 1053 potentially eligible citations. After removing duplicates, screening titles and abstracts, and reading full texts, 34 articles were found to be relevant. The quality assessment of the included studies showed a relatively poor quality. In terms of study setting, 18 and 16 studies have been conducted in inpatient and outpatient settings, respectively. All studies focused on potential DDIs while no study assessed actual DDIs. The median incidence of potential DDIs in outpatient settings was 8.5% per prescription while it was 19.2% in inpatient settings. The most indicated factor influencing DDIs incidence was patient age. The most involved drug classes in DDIs were beta blockers, angiotensin-converting-enzyme inhibitors (ACEIs), diuretic agents, and non-steroidal anti-inflammatory drugs (NSAIDs). Thirty-one studies were observational and three were experimental in which the strategies to reduce DDIs were applied. Although almost all studies concluded that the incidence of potential DDIs in Iran in both inpatient and outpatient settings was relatively high, there is still no evidence of the incidence of actual DDIs. More extensive research is needed to identify and minimize factors associated with incidence of DDIs, and to evaluate the effects of preventive interventions especially those that utilize information technology.DARU Journal of Pharmaceutical Sciences 06/2014; 22(1):52. · 1.11 Impact Factor
- [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. · 4.78 Impact Factor