A Pharmacoepidemiologic Study of Drug Interactions in a Brazilian Teaching Hospital

Abstract

Cruciol-Souza JM, Thomson JC. A pharmacoepidemiologic study of drug interactions in a brazilian teaching hospital. Clinics. 2006;61(6):515-20. PURPOSE:Although drug-drug interactions constitute only a small proportion of adverse drug reactions, they are often predictable and therefore avoidable or manageable. There are few studies on drug-drug interactions from Brazil. This study aimed to assess the frequency of drug-drug interactions in prescriptions and their potential clinical significance in patients of a Brazilian teaching hospital. METHODS: From January to April 2004, a sample of 1785 drug prescriptions was drawn from a total of 11,250. Drug-drug interactions were identified by using Micromedex ® DrugReax ® System. Patients´ records with major drug-drug interactions were reviewed by a pharmacist and a medical doctor looking for signs, symptoms, and lab tests that could indicate adverse drug reactions due to such interactions. RESULTS: From the 1785 prescriptions examined, 1089 (61%) were from the male adult ward. Patients' average age was 52.7 years (SD = 18.9; range, 12-98). The median number of drugs in each prescription was 7 (range, 2-26). At least 1 drug-drug interactions was present in 887 (49.7%) prescriptions. Regarding the severity of the clinical result, the interactions were classified as minor (20; 2.3%), moderate (184; 20.7%), major (30; 3.4%), and undetermined because of an incidence of more than 1 interaction in a single patient (653; 73.6%). From the 30 patients with major interactions, 17 (56.7%) presented adverse drug reactions induced by exposure to a major drug-drug interaction. CONCLUSIONS: Patients did suffer adverse drug reactions from major drug-drug interactions. Many physicians may be unaware of drug-drug interactions. Education, computerized prescribing systems and drug information, collaborative drug selection, and pharmaceutical care are strongly encouraged for physicians and pharmacists.

Prevalence and Pattern of Potential Drug-Drug Interactions in the Critical Care Units of a Tertiary Hospital in Alexandria, Egypt

“…These findings were in accordance with other studies which showed that both variables were indeed two of the major, if not the most important, risk factors for DDIs [6,14,[27][28][29]. Other risk factors for the occurrence of DDIs identified by other studies included sex [27] and length of hospital stay [4,6]. Although the current findings showed that DDIs were not preventable, awareness of the medical team on the prevalence, risk factors and mechanisms involved in the occurrence of potential DDIs can help in the reduction of the real occurrence of DDIs among hospitalized patients in general and the critically ill patients in specific.…”

“…Logistic regression analysis for the possible risk factors of DDIs among patients admitted to the CCUs in the present work showed that the age of patient and the number of prescribed drugs were the only significant factors. These findings were in accordance with other studies which showed that both variables were indeed two of the major, if not the most important, risk factors for DDIs [6,14,[27][28][29]. Other risk factors for the occurrence of DDIs identified by other studies included sex [27] and length of hospital stay [4,6].…”

“…The study highlighted a 53.07% prevalence of potential DDIs that would have resulted from the combinations of the prescribed drugs. This finding was comparable with those reported in other studies [5,27]. Higher rates were reported from Brazil in 2008 [14] and 2011 [4] and from Switzerland in 2010 [28], while lower rates were reported from Canada in 2007 [29] and Egypt in 2009 [18].…”

“…Lower percentages of delayed onset potential DDIs, ranging from 48.7% to 61%, were reported by many other studies [5,14,15,27,30]. On the other hand, higher percentages of delayed onset potential DDIs were reported by Iranmanesh et al, in 2012 (89.2%) [31].…”

“…Other studies reported that nearly half of the interactions of moderate severity [14,30]. Higher percentages were found in several studies [5,15,27,29,31].…”