Yes, it could. If you are already taking a course of pharmaceutical drugs, then the more natural alternative of cannabidiol may have unintended consequences. Again, this is an area in which research is ongoing. Indeed, how one drug interacts with another in the human body is something medical science only has a burgeoning grasp of. However, some anecdotal evidence suggests that CBD can cause the effects of other drugs to lessen or even not work at all. Some people get unwanted or more pronounced side effects from the prescribed drug treatment after taking cannabidiol supplements. In short, the picture is mixed so proceeding with caution is wise. If you have any doubts, then consult a medical professional about the likeliest outcomes in your case.