Drug Interaction Report

MONITOR: Concomitant use of flaxseed oil with ezetimibe may lead to lower plasma alpha-linolenic acid (ALA) levels. The mechanism may be related to ezetimibe-mediated inhibition of intestinal absorption of ALA contained in flaxseed oil. However, data for this interaction are conflicting. In one study, 34 cardiac disease patients were randomized into 4 groups for a 6-week trial of a daily dose of either: placebo, 10 mg ezetimibe, 2 g flaxseed oil (equivalent to 1 g ALA), or 10 mg ezetimibe with 2 g flaxseed oil. The flaxseed oil group presented a significant increase in ALA plasma levels of 6 mcg/dL, and the other groups showed a decrease in ALA plasma levels of 2 to 4 mcg/dL as compared to baseline. However, according to ezetimibe product labeling, preclinical studies showed no effects of ezetimibe on fatty acid absorption.

MANAGEMENT: Until further information is available, clinical or laboratory monitoring of the expected therapeutic benefits of flaxseed oil is recommended when ezetimibe is co-administered with flaxseed oil.