Potentially, yes.

All competitors must submit a medical evaluation form; on that form is a requirement to list all medications. It also requires that the doctor sign the form stating that either they recommend approval, or recommend the application be reviewed by SCCA's Medical Review Board (MR. I suggest any doctor worth their salt would refer the issue to the MRB.

From the GCR:
Many medical conditions affect a competitor’s fitness. Certain conditions will be automatically reviewed by the Club Racing Medical Director and the Medical Review Board to determine whether a competitor should be issued a license. Specific medical conditions that preclude issuing a license are varied and change with improving medical treatments. The medical reasons for denying a license will be explained to the applicant. Actions of the Medical Review Board are final and are not subject to protest.
I am not a doctor, nor do I have direct experience with this process. But I recommend you contact the SCCA directly prior to going through all the trouble of application/medical. You'll want to submit a query to the MRB and ask them if the specific drug you're taking is automatically disqualifying. If it is, you've saved wasting your time. However, if it is not automatically disqualifying then I recommend going through the process, see what happens...

GA