If my girlfriend is currently abusing drugs and I want to remove our son from the situation ASAP, what are my legal rights to take him out of state?

Unless you have a written court order allowing you full physical custody of your son you cannot simply take your son with you out of state regardless of issues that your girlfriend has with drug abuse. I suggest that you consult with a family law attorney about the situation you are writing about where a possible filing of a petition to the court seeking the relief you want be made. However, if your girlfriend signs a written agreement prepared by a family law attorney allowing you to take your son out of state before a notary public, such would preclude the need of the suggested petition that I wrote about.