I think it would depend on a few different things. I'd probably in general rather not do medications/drugs if it can be avoided, but of course there will be cases that it can't really be avoided.
Firstly, it would probably depend on the situation/what the problem is. If it were a condition, like I said above, that could potentially be treated some other way, then I'd totally go for the other way. And I'd be wary of giving any medications, so would probably want some sort of second opinion.
It would probably also depend on side effects of the drug, etc... as in if it would do more damage than help. Also would depend on teh breed, etc... like if the breed I owned was predisposed to get a certain illness or something, I probably wouldn't want to use a medication that made the dog/other animal at higher risk for that illness. If that makes any sense
Chrisanne brings up a good point too... that just using medication for EVERYTHING isn't really a good idea.
And what Mandie said kinda makes sense too. I'm nto sure it's totally wise to juts medicate an overly aggressive dog and totally trust the medicine... things can go wrong and something could happen.
Overall, I would if I needed to, and if there wasn't a "better" way, but I'd probably consider it a good bit before putting my dog on meds.