When I was a Newbie, I worried about this too. After some research, I discovered that you are safe in the ports. The areas of concern is if you are staying weeks at a time in a jungle area. If that was the case, you have missed your ship, and have bigger worries.
I think you will do just fine without the meds, unless you have a problem medically, and in that case, your Dr. would be the best one to advise.