I'd say I've filled about half the prescriptions I've been given by doctors over the years. Thankfully, I haven't needed to go that often - last time was about 5 years ago. But you'll rarely come out of a surgery without a prescription, whether you need it or not. Antibiotics, painkillers, statins, tranquilisers, anti-inflammatories, sleeping pills are all massively over-prescribed. And usually without any discussion of side-effects, long term effects, etc. The medical profession seems to be obsessed with chemical solutions to every problem. They're great when they're appropriate, but they're not always appropriate.
Typically, I've use the visit for a diagnosis and then decided for myself whether I'll need the stuff they prescribe to get over whatever the problem was or whether the cure might be worse than the disease.