I had the same concerns and found Divers Alert Network/DAN to be the best resource. They have alot of info info on there web site and have Doctor’s that dive. I printed out info on aproved meds from there web site and gave the info and there phone number to my Dr so he could prescribe dive aproved blood pressure meds. Most Dr are not very knowledgeable in dive related medicine.DAN can allso refer you to Dr’s that are knowledgeable in diving issues.
I have found you have to research it youself and educate your Dr with specific concerns.