If I could have my way, I would prevent drug companies from doing true advertising. The reason for this is that the sorts of misleading ads that all firms make have more important consequences when they are advertising pharmaceuticals.
Of course, all ads are somewhat misleading. The whole point of an advertisement is to make you want something that you might not otherwise want. This seems harmless enough when you are being made to want a certain brand of soda or the newest toy. But it seems much more harmful when it is designed to make you feel that you need the latest drug.
Our health care system is becoming terribly expensive. It is getting to the point where we will be less and less able to afford to provide medical care to everyone who needs it. At least part of this is due to the kind of enticing advertisements now put on by drug companies. They try to get us to pressure our doctors to prescribe expensive medicines for us and the doctors often have more incentive to just give in than to push back against our wishes. This causes us to end up paying for drugs we might not have needed, thus pushing health care prices up further.
For these reasons, I would like it if we could see (though I know this will not happen) drug companies being limited to less attractive forms of advertising.