It's not an "anti-drug" commercial... but it is a commercial against drugs. It is also the most awesomely funny commercial I've ever seen. Put out by the National Youth Anti-Drug Media Campaign, it's called "Cleaner Girl." It goes as follows:

Sound: Female voice singing, complete with backup chorus. Resembles the old folger's coffee commercials.
Action: Female 20-something, cleaning the house with a toothbrush, pawing at her skin, having hallucinations and generally falling apart on screen. But.. you know.. in a funny way.

Lyrics:
Look at me, busy as a bee! Where'd I get all this energy?!
Whoah-oh-oh meth, mmmmm meth!
I don't sleep, and I don't eat. But I've got the cleanest house on the street!
Whoah-oh-oh meth, mmmmm meth!
Get these hairs all out of my face! Get these bugs all out of my place!
One more hit, no time to waste!
Whoah-oh-oh meth! MMMmmMmm Meth!

*note: I don't know any of the credits from the commercial, but the lyrics I have transcribed myself. You can find a copy of the commercial at http://www.mediacampaign.org/mg/television.html