If you are already paying for health insurance that covers medications, yeah you'd save money. I hear about individuals requesting for a ibuprofen script because they save money getting the extra strength pills @ a large quantity. The doc is more than happy to script it because for one they are in pain, and two it saves them a lot of money as the insurance wont pay for the 10 dollar bottle of however many pills if it isn't scripted.
Also doctors aren't stupid and realize that if the medication is going to be cheaper to be bought OTC (instead of paying for a doc appt to get refills, etc) they will tell you to buy them OTC. Or if it will be cheaper to buy it via script, they'll write you a script. I've been scripted senna-s, and I saved money getting a script of it instead of buying it OTC. I buy fish oils and baby asprin OTC because it is really cheap, and I don't need to see the hematologist every now and then for a check up (I have a history of blood clots so I need to take them).