Is 20 shots of alcohol with mixer in one night really bad?

When I have a drink at home with vodka, I usually have a ‘quadruple vodka’. Basically 4 shots (100ml) topped up with coke. I might have 4 of these over the course of the night (6 hours), so 16-20 shots in total. Is this ridiculously bad? I don’t get really drunk. I usually get more drunk in nightclubs, drinking less!