I don't know what you mean by "medications," that's usually a drug taken deliberately for a specific illness, to help soothe or heal. Taking something for its side effects rather than its actual purpose is not too good because there are usually better medications for whatever side effect one wants. That being said, I occasionally take a children's Benadryl or other antihistamines (allergy meds) at night to help me get to sleep. But taking anything to "get away" from a situation or if one acts contrary to one's usual nature (having sex while drugged or drunk, for example) is not a good idea for obvious reasons.

Medications are not "just" what they say or their side effects; many (most?) of them are really sloppy at what they do and can cause very serious problems, even if taken properly. I wouldn't take anything for "fun" or the feeling it gives me (what I think you're calling the side effect) as the consequences are usually similar to eating or drinking too much or the wrong things, only faster. One can eat too much junk food and suffer a heart attack or one can take a few of the "wrong" meds and suffer a heart attack; the foods usually slower though and more "predictable".

But I wouldn't call what you are describing "abuse," just not very effective and potentially dangerous.