Smoke & Gunfire Don’t Always Go Hand in Hand
Is legalized cannabis use causing medicinal users of the substance have to make a hard choice between concealed carry and their medicine? It appears so. Although handling a firearm while under the influence of any drug or alcoholic beverage is a big mistake, there is nothing that would keep a concealed carry permitted gun owner from carrying a concealed weapon and taking RX medication or drinking alcohol as long as the two aren't done simultaneously.
With the conflict between federal law and many new state laws surrounding Marijuana (regardless of its purpose for use) it leaves US residents in conflict. Federal law makes it illegal to possess a firearm when in the possession and use of a controlled substance. There is no exemption for Cannabis. So, as you can see the conflict is real. Own a gun, no medicinal marijuana, plain and simple. And this isn't just about simultaneous use, if you have a concealed carry license and subsequently use a controlled substance you could get in some real trouble with the feds. From the other angle, the rules are no different. If you use Cannabis, the Federal Government will not allow you to own a firearm.
Hopefully, someday all of this will be sorted out but while the conflict rages on keep yourself clear of the crossfire.