Purpose: Although moderate drinking has been associated with lower mortality among patients with coronary heart disease, its safety among patients taking common cardiac medications is unknown.
Subjects and methods: We studied 1244 men enrolled in the Post-Coronary Artery Bypass Graft (CABG) Trial who had undergone previous coronary bypass surgery. Participants were randomly assigned to lovastatin in low (mean 4 mg) or high (mean 76 mg) doses and to low-dose warfarin (mean international normalized ratio [INR] 1.4, goal INR <2.0) or placebo in a factorial design. Participants underwent routine measurement of alanine aminotransferase (ALT) and INR levels every 6 to 12 weeks for 4 to 5 years. We categorized weekly alcohol intake as abstention (<1 drink), light (1-6 drinks), moderate (7-13 drinks), and heavier (> or =14 drinks).
Results: During follow-up, 66% of men taking warfarin had an INR of 2.0 or higher, and 7% of men had an ALT of 80 IU/L or higher. Maximum INR (P = .72) and ALT (P = .51) levels did not differ across categories of alcohol intake. The risks of an INR of 2.0 or higher were 67%, 66%, 68%, and 61% among non-, light, moderate, and heavier drinkers (P = .86), respectively. The corresponding risks of an ALT of 80 IU/L or more were 8%, 10%, 9%, and 6% (P = .70), respectively.
Conclusion: Moderate drinking did not adversely influence the safety of low-dose warfarin or even high-dose lovastatin among men in this randomized trial, as measured by INR and ALT levels.