Are people with MS hypersensitive to medications due to increased blood brain permeability? Are they at increased risk to develop side effects to meds that don’t typically cross the BBB? What are the implications for medication administration?

I have not been able to find any research studies on this topic. Personally, I feel like I am hypersensitive to medications and this has led to fear when starting new medications. I always ask my doctors to start at the lowest dose possible. I wonder how this affects medication‘s like anesthesia, chronic illness medications for diabetes, cardiac conditions, and thyroid, and pain medications. What type of drugs can leak into the CNS either through lesions or micro changes in the CNS?