Drug Interaction Decreases Clopidogrel's EffectivenessAschenbrenner, Diane S. MS, APRN, BCAJN The American Journal of Nursing: March 2010 - Volume 110 - Issue 3 - p 55-56 doi: 10.1097/01.NAJ.0000368957.03506.0f Drug Watch Abstract Author Information The labeling for clopidogrel (Plavix) has been revised to indicate that when the drug is taken together with the proton pump inhibitor omeprazole, a drug interaction may occur that can decrease clopidogrel's therapeutic effectiveness. Patients requiring drug therapy to decrease gastric acidity while taking clopidogrel should take either an H2-antagonist (excepting cimetidine) or an antacid. Diane S. Aschenbrenner is the course coordinator for undergraduate pharmacology at Johns Hopkins University School of Nursing in Baltimore, MD. She also coordinates Drug Watch: email@example.com. © 2010 Lippincott Williams & Wilkins. All rights reserved.