Evaluation of drug information resources for drug-ethanol and drug-tobacco interactions

OBJECTIVE: The research evaluated point-of-care drug interaction resources for scope, completeness, and consistency in drug-ethanol and drug-tobacco content. METHODS: In a cross-sectional analysis, 2 independent reviewers extracted data for 108 clinically relevant interactions using 7 drug information resources (Clinical Pharmacology Drug Interaction Report, Facts & Comparisons eAnswers, Lexicomp Interactions, Micromedex Drug Interactions, Drug Interactions Analysis and Management, Drug Interaction Facts, and Stockley’s Drug Interactions). Scope (presence of an entry), completeness (content describing mechanism, clinical effects, severity, level of certainty, and course of action for each present interaction; up to 1 point per assessed item for a total possible score of 5 points), and consistency (similarity among resources) were evaluated. RESULTS: Fifty-three drug-ethanol and 55 drug-tobacco interactions were analyzed. Drug-ethanol interaction entries were most commonly present in Lexicomp (84.9%), Clinical Pharmacology (83.0%), and Stockley’s Drug Interactions (73.6%), compared to other resources (p<0.05). Drug-tobacco interactions were more often covered in Micromedex (56.4%), Stockley’s Drug Interactions (56.4%), Drug Interaction Facts (43.6%), and Clinical Pharmacology (41.8%) (p<0.001). Overall completeness scores were higher for Lexicomp, Micromedex, Drug Interaction Facts, and Facts & Comparisons (median 5/5 points, interquartile range [IQR] 5 to 5, p<0.001) for drug-ethanol and for Micromedex (median 5/5 points, IQR 5 to 5, p<0.05) for drug-tobacco, compared to other resources. Drug Interaction Facts and Micromedex were among the highest scoring resources for both drug-ethanol (73.7%, 68.6%) and drug-tobacco (75.0%, 32.3%) consistency. CONCLUSIONS: Scope and completeness were high for drug-ethanol interactions, but low for drug-tobacco interactions. Consistency was highly variable across both interaction types.