I also had that book in school! way too much info.
I think to study read the chapter summaries and study your powerpoints if you’re lucky enough to have them.
One book that is helpful and is not a big heavy text book is Pharmacology from the Reviews and Rationales series by someone Hogan. You can find it on amazon. I found that Pharmacology Made Incredibly Easy dumbs it down too much.
To memorize it helps to know the categories of drugs and each categoires suffix.