No absolutely not. Being a doctor is mostly hands on and in today's technology driven world, there are preloaded programs that would allow you to give your patients a visual of the things that you are trying to show them so there is no need to be able to draw unless it is just something that you want to do or enjoy doing in your spare time. As for professionally, not at all will you need this.
Whether you have the ability or not to draw is not an issue when it comes to excelling either in medical school or as a physician.
If you wish to pursue an interest in drawing, painting, etc. it can add much to your own personal enjoyment and expansion as a person.