This post is a few days old, but I'm frequently in this situation. I'm expected to drink with customers and management. I have had to rely on excuses (I'm on medication for example) because reality is some people just don't understand abstainers. I had a boss who used to tell us "I don't trust people who don't drink." so while many many people here will tell you we are over sensitive and people don't care if you don't drink, I have seen otherwise in certain situations. That being said, "I don't drink" or "no thanks" have not been good enough in my business situations. I have used "I'm on medication" (true) or "I'm training" or "I'm cutting out calories ".