The general topic of why we have prescription drug laws seems pretty easy to answer. One, a huge number of drugs on the market become habit-forming very fast. These medications often make a formerly rational person begin to act irrationally in order to serve the habit. Rush Limbaugh makes a bad example since he was never rational, but you get my point. In an uncontrolled environment practically everybody who has an addictive personality, which is a very large number of people, will have a habit by their eighteenth birthday.
Second, even professional pharmacists have a hard time keeping up with the huge number of dangerous drug interactions. Some interactions are automatically bad, some become risky with certain medical complications. The libertarian model hardly breaks down if consumers are willing to take risks that doctors are not, but it absolutely depends on consumers’ ability to gauge risks accurately. When it comes to prescription drugs the concept of a fully informed consumer becomes untenable.
So there you have it – what libertarianism really looks like and why, in my view, it doesn’t work.