If you are the pharmacist,
"Hey Walgreens (or Rite Aid if you work at Wal) offered me X dollars more per hour and they matched my vacation time, I don't want to leave but I need you to match or get close to their offer"
Thats all it takes, plus it helps if you have a good relationship with your district manager. Just the hint of a vacancy makes most managers lose sleep at night so they'll probably pony up.