Garlic (Allium sativum) has been shown to help prevent atherosclerosis (hardening of the arteries), perhaps by reducing the ability of platelets to stick together. Interfering with the action of platelets results in an increase in the tendency toward bleeding and in theory could dangerously enhance the effect of ticlopidine. Standardized extracts of garlic have been associated with bleeding in people only on rare occasions. People taking ticlopidine should consult with a doctor before taking products containing standardized extracts of garlic or eating more than one clove of garlic daily.

Garlic (Allium sativum) has been shown to help prevent atherosclerosis (hardening of the arteries), perhaps by reducing the ability of platelets to stick together. This can result in an increase in the tendency toward bleeding. Standardized extracts have, on rare occasions, been associated with bleeding in people. Garlic extracts have also been associated with two human cases of increased warfarin activity. The extracts were not definitively shown to be the cause of the problem. People taking warfarin should consult with a doctor before taking products containing standardized extracts of garlic or eating more than one clove of garlic daily.

Test tube studies show that watercress, garlic, tea, and cruciferous vegetables, such as Brussels sprouts, broccoli, and Chinese cabbage, block the breakdown of chlorzoxazone into inactive compounds. Controlled human research is needed to determine whether these interactions are important in people taking chlorzoxazone.