No, that's not how it works. The drug makers incur alot of expense on R&D, and come up with ever-new drugs, based on public demand, and the public wants all the new drugs, because he/she doesn't have to pay for them. Oftentimes, these new drugs serve the same purpose as the old drugs, which are inexpensive, but people are suckers for a TV ad, and are always looking for the newest and most effective drug to cure what ails them.
If people had to pay for their own drugs, they would shop around and price compare, and get the best value for their money. They don't have to do that, and the insurance company has no personal vested interest in containing costs, as long as they keep getting their monthly premium. That is the primary problem. Those who use health care do not have to be conscious of how much health care costs. If they did, they would try to keep costs down by buying affordable drugs and taking care of their own health.