Copyright 1998 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.1998
In Reply.—A variety of clinical factors have been reported to cause excessive warfarin effect. The goal of our study was to quantify the impact of such factors in real-world clinical practice. Patients in our study were asked about use of over-the-counter medications, including vitamins, and recent changes in vitamin intake. None of the patients with an INR higher than 6 reported a change in their daily intake of vitamins during the week preceding the INR determination.
Hylek EM. Acetaminophen and Risk Factors for Excess Anticoagulation With Warfarin—Reply. JAMA. 1998;280(8):695-697. doi:10-1001/pubs.JAMA-ISSN-0098-7484-280-8-jbk0826