Pharmacology 101

Basically as a RN if you are giving a drug to anyone you should know how that drug works, why you are giving it and what can go wrong with it.  Would you want a nurse giving your family member a drug they don't know about or what could go wrong with it? Probably not. 

No nurse has any business giving a drug to their patient if they don't know a drug's mechanism of action, contraindications, indications, side effects, etc.  I don't expect a RN to know cellular level MOA but they should understand the basics.

Drugs are kind of a big deal and you need to know them.  Sometimes, my patients have home meds that I’m not super familiar with and I still look it up before I give it.  
 

People can die if you don’t understand your meds.

specific drug doses: No, we were never tested on the drug doses in either of my pharmacology classes. In peds we were asked to do all calculations to ensure that the drug matched the order since everything is dosed based on weight, but in adults you sort of see enough of the major drugs to understand what is a "normal" dosage and what looks suspicious

drug classes/drug names: really focus on your classes if this is your first pharm course. the classes usually have an ending or prefix that helps you identify the names to the class (beta blockers ending in -LOL for example). In general, most drugs have similar side effects or life-threatening/overdose symptoms within their class, so if you can understand the class, the ending/prefix, why you'd give it, why you wouldn't give it, and what side effects are expected vs. dangerous you should do fine. I wouldn't worry so much about the cellular mechanisms.