We have a megaphone at our disposal, the question is how to use it effectively. Warnings are pointless - we put all sorts of warnings on the medications we dispense, but I attend probably two to three lectures a year on how ineffective these warnings are. People don't read them - we're lucky if they read and understand the directions. Some states require spoken counseling on instructions and side effects because so few people read warnings and other information when they receive medication. Warnings on Wikipedia drug articles are unlikely to be all that effective, and if you start putting specific disclaimers on these you will need to start doing it on hundreds of other categories of articles as well.
We do have the {{drugbox}} infobox template, it contains all sorts of handy links. But it is very clearly directed at medical professionals - most people won't have a clue what the various bits of information mean, or what to look for when following the links. I think it would make sense to redesign the template to be more accessible to the regular reader (including such information as a link to a gallery of dosage form images, common side effects with percentages, class in lay terms [i.e. antidepressant instead of SSRI], maximum safe dosage for a child and an adult, pregnancy category [again, in lay terms instead of the letter], etc.).
I'm not sure that keeping the dosage information has much beneficial impact - on the one hand you discourage self-medicating, but on the other you don't tell people what the maximum dosage is, and that information might be crucial if they are in fact self-medicating.
Nathan