When I began nursing school, I thought that I would study individual drugs for NCLEX. Even the drug cards available in drug guides focus on individual medications. However, what is more important is being familiar with the general class of drugs, because that is what NCLEX wants you to know. When I discovered this, I started making these drug cards that focus on certain types of medication and can give me a snapshot of the drug classes that fit within it.
The link above will give you access to the following anti-diarrhea drug classes: adsorbents, anticholinergics, intestinal flora modifiers, and opiates.