Clinical Weighting of Drug–Drug Interactions in Hospitalized Elderly

Abstract

Adverse drug reactions impact on patient health, effectiveness of pharmacological therapy and increased health care costs. This investigation intended to detect the most critical drug-drug interactions in hospitalized elderly patients, weighting clinical risk. We conducted a cross-sectional study between January and April 2014; all patients 70 years or older, hospitalized for >24 hr and prescribed at least one medication were included in the study. Drug-drug interactions were estimated by combining Stockley's, Hansten and Tatro drug interactions. Drug-drug interactions were weighted using a risk-analysis method based on failure modes, effects and criticality analysis. We calculated a criticality index for each drug involved in the drug-drug interactions based on the severity of the interaction mechanism, the frequency the drug was involved in drug-drug interactions and the risk of drug-drug interactions in patients with impaired renal function. The average number of drugs consumed in the hospital was 6 AE 2.69, involving 160 active ingredients. The most frequent were as follows: Furosemide, followed by Enalapril. Of drug-drug interactions, 2% were classified as contraindicated, 14% advised against and 83% advised caution during the hospital stay. Thirty-four drug-drug interactions were assessed, of which 23 were pharmacodynamic drug-drug interactions and 12 were pharmacokinetic drug-drug interactions (1 was both). The clinical risk calculated for each drug-drug interaction included heparins + non-steroidal anti-inflammatory drugs (NSAIDs) or Digoxin + Calcium Gluconate, cases which are pharmacodynamic drug-drug interactions with agonist effect and clinical risk of bleeding, one of the most common clinical risks in the hospital. An index of clinical risk for drug-drug interactions can be calculated based on severity by the interaction mechanism, the frequency that the drug is involved in drug-drug interactions and the risk of drug-drug interactions in an elderly patient with impaired renal function.Drug-related problems (DRP) are a very important public health concern that cause adverse drug reactions (ADR), which impact on patient health, effectiveness of pharmacological therapy and increased healthcare costs [1]. Drug-drug interactions have been reported to account for 5.6% to 63% of medication-related problems (MRPs), particularly in elderly patients, where the prevalence of at least one drug-drug interaction is about 46% [2]. The conditions of elderly patients, such as a decline in the functional capacity of most organs and systems, comorbidity and, in turn, polypharmacy (more than five drugs), make this population more susceptible to drug-drug interactions, resulting in a long hospital stay or death [3,4].There are many studies that report the prevalence of drugdrug interactions, while focusing on identifying the implicated drugs and the type of clinical effect on the patient [5,6]. Currently, research has focused on knowing the DDI action mechanisms, which allows assessment of their relevance and ...

Evaluation of Potential Drug-Drug Interactions (DDIs) Incidence in Critically ill Patients

“…[1,3,5,23,24] In this study, most of the interactions were significant in nature, followed by minor interactions and serious interactions. Contraindicated interaction was found in only 0.1% of the case; this proportion was lower compared with a proportion of as reported in a study conducted by Juárez-Cedillo et al [25] The significant type of interactions was found prominently in patients with cardiovascular co-morbidities; whereas, minor type of interactions was observed more in diabetic patients. No significant difference was found in pharmacokinetic (21.4%) and pharmacodynamic (20.1%) interactions.…”

Potential drug–drug interactions and polypharmacy in institutionalized elderly patients in a public hospital in Brazil

“…Regarding the severity of the DDIs, the frequency of serious and contraindicated interactions was higher than that reported in previous studies on hospitalized elderly patients (Gotardelo et al, 2014;Juárez-Cedillo et al, 2016;Pasina et al, 2013). Considering that numerous patients are often frail due to multiple diseases and complex treatment regimens, the clinical effect of these interactions should be analysed.…”

Prevalence of drug interactions in hospitalised elderly patients: a systematic review

“…Fifteen studies analysed DDIs through the Drug-Reax System (also known as Micromedex),27–30 32–36 38 39 43 47 50 58 five studies analysed DDIs using Beers criteria,37 40 41 44 45 four studies analysed DDIs using the Medscape Drug Interaction Checker38 46–48 and two studies used the Epocrates Interaction Check 47 54. Ten studies evaluated DDIs with more than one type of software 15 29 35 36 38 39 42 45 47 51. Textbooks were employed in nine studies 15 29 35 38 39 42 49 51 59.…”

“…Sample size varied from 44 to 1510, totalling 9577 patients. The majority of papers were cross sectional and from developing countries: 9 studies were from Brazil,27–35 6 studies were from India,36–41 2 from Mexico,42 43 2 from Croatia,44 45 1 from Venezuela,46 1 from Serbia,47 1 from Nepal,48 1 from Iran49 and one from Ethiopia 50. The remaining 10 studies were from Spain,51 52 Norway,53 Portugal,54 Germany,55 Italy,56 Austria,57 Israel,58 Canada15 and Australia 59.…”

“…Ten studies evaluated DDIs with more than one type of software 15 29 35 36 38 39 42 45 47 51. Textbooks were employed in nine studies 15 29 35 38 39 42 49 51 59. In one case, the source for DDI evaluation was locally adopted lists53 and in another, databases that were not explicit 55 Online supplementary table 2.…”