hey there,
I was just having this discussion with another boozer, sorry, person who likes a relaxing drink, earlier today.
A pint of fizzy lager is about 8g of carbs, about the same as a couple of fresh apricots. A pint of proper beer is about 17g of carbs, about the equivalent of a medium large apple. Cider's similar to ale unless it's sweet, when it's about 25g of carbs, about the equivalent of a large banana.
Wine (unless it's sweet) has hardly any carbs - 2g for a large glass of dry white - do not inject to cover wine. Whisky, gin etc has no carbs.
How to balance this with the hypo risk is the problem, and there's no general rule of thumb because everyone is slightly different - you have to experiment and see what happens. If it helps, though, what I do is this:
1 pint of beer - I usually don't inject. But you might want to - depends on your insulin/carb ratio really.
2 pints of beer - I would inject to cover the second pint.
3 pints of beer - I might inject to cover it. I might not. I would probably have scoffed at least some of someone else's crisps by now, too, so I would probably inject partly for that
4 pints of beer - at this point I would definitely stop injecting. There's enough booze in me now to be affecting my liver into the next day.
any more than that - no. no injection.
Also, if at any point I'm following any of this beer with whisky chasers, NO INJECTION.
As I say, this is what works for me. It may not work for you. I tend to think, if I'm on the beer but starting to feel nicely drunk, I should probably stop injecting.
Don't forget that if you are hungover, your liver will probably still be out of action, so take that into account when calculating next morning's insulin dose. (ie maybe take a bit less, or eat a bit more).
hope that helps. Cheers!