Detecting Drug Interactions: A Review of the Literature

Abstract

This article provides a historic overview of drug interaction screening and reviews 19 studies that have sought to measure the frequency of drug interactions. Differences in study designs, methodologies, and definitions contribute to considerable variation in the reported incidence rates, which ranged from 2.2 to 70.3 percent for all potential drug interactions. The percentage of patients actually experiencing symptoms that could be attributed to a drug interaction, however, ranged from 0 to 11.1 percent. The relative importance of drug interactions as a clinical problem remains unclear. Screening programs that do more than simply identify large numbers of patients who receive potentially interacting drug combinations without indicating which subpopulations of these individuals are likely to be harmed by the drugs have not yet been developed.

Incidence and Severity of Potential Drug–Dietary Supplement Interactions in Primary Care Patients

“…28,[30][31][32][33][34] However, because safety problems may be underrecognized and underreported, we encourage all health care providers to question patients about dietary supplement use, especially because there are increasing reports of significant morbidity and mortality, with or without concomitant pharmaceutical use. 9 In addition, health care providers should consider potential drug-dietary supplement interactions, regardless of the severity of the potential interaction, because even minor interactions can affect drug therapy and patient quality of life.…”

“…Although our incidence rates may seem low at first glance, these results correspond reasonably well with the 2% to 3% estimate of severe drug-drug interactions noted by Peterson and Bates, 30 and approximate the range of incidence rates seen for potentially serious drug-drug interactions found in various ambulatory populations. 28,[30][31][32][33][34] Since our study was initially completed in 1999, we considered that newer information on interactions might alter the incidence rate of potentially serious interactions. To address this, we completed a second MEDLINE search in late 2001 and also reassessed our findings using a more contemporary, comprehensive reference on drug-dietary supplement interactions.…”

Management of potential drug interactions in community pharmacies: a questionnaire-based survey in Switzerland

“…Reported incidences in outpatients range from 9.2% to 70.3% for drug interactions of any severity, and from 1.2% to 23.3% for those considered of major relevance [5][6][7][8][9][10][11]. A German primarycare study showed that of all observed major or moderate potential drug interactions only 11.7 % offered no management options, and such drug combinations should thus be avoided [12].…”

Pharmacy Students' Ability to Identify Potential Drug-Drug Interactions

“…The prevalence of potential DDIs is far from trivial. 1,5,7,19,20 A study of pharmacy records from VA ambulatory care clinics found that the rate of exposure to 25 potential DDIs was 2.2%. 20 Another study on the frequency of potential DDIs in a pharmacy benefits manager's drug database revealed that the potential DDI pair with the highest prevalence rate (warfarin/non-steroidal anti-inflammatory drug) occurred at a rate of 279 per 100,000 persons.…”

“…DDIs occur in 9% to 70% of patients in the outpatient setting. 5 Computer programs and drug compendia are commonly used to assist pharmacists in recognizing drug interactions, but the usefulness of these tools is limited. For example, DDI software programs identify both clinically significant and nonsignificant drug interactions, making it challenging for pharmacists to interpret DDI warnings.…”