Umm, good question. Actually, I think my doctor told me that pills that are taken sublingually tend to work more quickly but it probably depends on the medication. I know Levsin (which is a smooth muscle relaxer) works better that way, as does Ativan. I don't know about opioids (or other types of pain medications) as I have never tried it that way, the taste is always nasty. I would just swallow those or crush them up if you're having a difficult time.

As far as your second question, I have not tried a lot of drugs so I couldn't answer that but everyone reacts differently to drugs.