It's not like you can (or should) convince a doctor that a certain kind of drug would be better for you, after all they are the professionals.

One thing I learned when studying pharmacology was that you should research your own medication (if you have a reasonably good understanding of science and cause/effect) because your doctor - especially GPs - probably doesn't know that much about every medication. Do enough digging that you have questions to ask them. Check the LD50 of every drug. Check "side effect" rates. You have incredibly complex pathways with every single drug, and even drugs with really similar compositions can have about twelve different effects from the others. With as many drugs as there are in the market, it's pretty impossible for doctors who aren't specialists of any particular field to keep up with them.

The reality of the situation is that pharmaceutical representatives are the real source of information on the drugs they are selling for practitioners, unless the doctor wants to read up on every different kind of medication passing through the office. They should, but with busy schedules and hundreds of medications, lots of things get overlooked.

On top of all this, lobbyists keep drugs that have been proven to cause life threatening problems on the market. The example springing to my head would be Celebrex, which is a very specific kind of NSAID used to treat chronic migraine, is linked to cardiac arrest and other cardiovascular problems in alarming rates. The company has decided it's more profitable to pay the lawsuits for these deaths versus take it off the market, while sticking a little sidenote in tiny lettering that it can cause cardiac arrest and death.

Overall, if the potential for monetary gain off of pharmaceuticals wasn't so high in the US, i.e., if they could not be advertised and marketed so readily, the occurrence of this would go down. However, I strongly urge anyone to really drill their prescribing doctors with specific questions about any prescription you'll need to take on a long term basis. It's also important to note that the word "side effect" is completely fabricated by companies to try to draw your attention away from whatever particular effect they are marketing the drug's intentional use for. Every effect stems directly from taking the drug, and should be considered and weighed as heavily as the intended purpose of the drug.