Cardiac Patients taking Alcohol and Viagra

Hello, I am working on my BSN and I need to do a teaching assignment for my Public Health Nurse certification. I have researched a bit and found that many cardiac patients want to know if they can still have sex, can they use Viagra, and if they can drink alcohol still? I know that their physicians should advise however I would like to know what you Cardiac nurses tell your patients and what you have heard the Docs telling their patients about them?
Thanks,
Catfish