If you play again, you'll know to bring lots of drugs to
the boss every fight. Remember you can use them before combat starts. When you got 20 AP and go first every turn, nothing can stop you. My Explorer/Big Game Hunter was able to empty the bulldog pistol every turn (with snapshot for 3 AP shots) when he was on Coca Vin Marie, Powdered Cocaine, Ferocity, and Ampheta-Man. The game is so short that being addicted to analgesics, tobacco, alcohol, AND cocaine isn't even a big deal.
For some reason, I did feel bad turning my dog into a junkie though.