Final answer:
The first step in drawing medication from a vial is to clean the rubber cap with an alcohol swab to ensure a sterile environment.
Step-by-step explanation:
When a nurse is preparing to draw up medication from a vial, the first action that should be implemented is b. rub vigorously back and forth over the rubber cap with an alcohol swab. This is a critical step to ensure aseptic technique and prevent contamination of the medication. After cleaning the top of the vial, it is often recommended to let the alcohol dry for a few seconds before inserting the needle. This step precedes drawing air into the syringe or connecting the needle firmly to the syringe.