Alcohol doesn't have quite the same effect as cough medicine. And yes, of course, anyone who is on medication should be careful of taking other things, even over-the-counter stuff.
I agree with those who are saying, take a class, join a club, or find some gathering of people who share one of your special interests or obsessions. If your first attempt doesn't work out, try a gathering related to a different interest. I recently forced myself to enroll in a class. I wept, wailed, and gnashed my teeth in between the enrolling and the start of class. My hair was falling out in handfulls from the stress. I nearly dissolved into panic the first few days at class. Later, all of a sudden, I realized that I had been greeting my classmates with a smile, and even engaging in breif conversations with them from time to time, without experiencing any of my usual social anguish. We're sharing an experience related to a shared interest, and that makes being with these people fairly easy, so this is turning out to be a more positive social experience than I have had in a very (very, very) long time.