I have always wondered why most drugs are bitter. Come to think of it, bitter drugs most often induce vomiting. So, why are drugs bitter? Is there a common ingredient that makes all of them bitter?

Can we not add sweeteners to drugs and still have them curing sickness?

I've always wondered about this too. Why can't drugs just be sweet so that people can take them with ease. I guess it re-enforces the saying that "Nothing comes easy".