I've been concerned I might have this problem before - though I've been told by a therapist that being concerned about a lack of empathy or ability to feel emotions other than anger/severe anxiety means that I don't have to worry as much, because I still want to make the right choices ergo not a sociopath. When I used to trip it was all fun and games until about a year or two ago when I really started having issues with empathy. Since then tripping and such has just made me really antsy and requires a lot of klonopin for me to enjoy at all. No fun. I enjoy dissociatives much more.
However I think I'm a poor example as I've just buried my emotions - working with doctors and practicing meditation to undo that damage.
The case of one of my former roommates is one you'd find more interesting (I actually went and changed my username before this post because I realized if he googled me he might find me saying this about him):
Dude was a complete psychopath (or APD if you wanna call it that). Lied about EVERYTHING. Where he went to college, why he was doing what he was doing, etc. Very violent at times. Beat the shit out of my other roommate multiple times (a girl) that was stupid enough to sleep with him. Abused his own mom, etc. Seemed to only have three states: pissed off/psychotic, crying/attention getting, and anxious. He was like me without any of my self knowledge or desire to change.
I've taken lsd with the guy as well as 2c-e and ketamine. No, I didn't notice the drugs giving him any empathy. If anything, they made him worse. With the 2c-e for example, I'd obtained 200mg and mixed it in with a certain quantity of water in a jar, and we were dosing it out using one of those medicine measuring cups you use for say cough syrup. My other roommate and I had left the room and when we came back, he was acting crazy and joking that he had just drank some of the rest and didn't know how much. My other roommate freaked out (she had never tripped before) and started screaming at him to go throw up or something. I on the other hand immediately went and measured the volume of liquid left and discovered there was MORE than there had been to start. I tested some of the remainder and found it was still potent. He had simply diluted the mixture but was absolutely hellbent on convincing us that he had taken an unknown amount of 2c-e, knowing he had been very unstable the past few weeks.
Moral of the story, the drug simply made him want to fuck with us even more. My other roommate (the girl) was terrified and worried, I was pissed off and angry, and he was obviously just laughing at the whole thing while tripping. So no, didn't give him any more empathy. The LSD and ketamine experiences exhibited similar things.
FYI this dude was arrested a few months ago for assault though nobody pressed charges (stupid girl wouldn't do it) and is now getting 'treatment' - though I can be pretty sure he's just becoming a better manipulator, so I think he's what you're looking for.