This is coming really late in the thread, but Fentanyl is lipophilic. The Duragesic patch works by having it seep into your skin, getting past the lipid bilayers of the skin cells, all seven or so layers of them, and into your bloodstream.

You know there's a drug called alfentanil? It's like opiate crack! The high is instant, 800 times stronger than morphine and 8 times as strong as Fentanyl. You can't separate pain relief from the euphoria, so I'm not breaking any laws by mentioning the high, I think. It's broken up by esterases within 10 minutes, and it's effectively inactive then. Crazy! Its trade name is Alfenta.

There's a related one, called Ultiva, that is metabolized so fast it comes in mg doses, but it's actually stronger than alfentanil, it's just cut up so quickly you have to use a ton of it. These two are part of a class of new opioids that are in and out tremendously fast, and for use in clinical settings, I guess. But who needs hardcore pain relief for only 5 minutes? Oh well, science moves ahead and society follows.

Also, I can't help but mention, but DXM, dextromethorphan, is the stereoisomer of levorphanol? For those of you who don't know these terms, stereoisomer means the mirror image, so the molecule is the same with bonds, ions, etc., but the bonds stick out in different directions in 3D space. The cool thing is that levorphanol is EXTREMELY strong, while DXM has very little binding to opiate receptors. Cool, huh? Just a little bar talk...

Noah