Relationship between FDA, companies, physicians, and patients:
a)    Company has to follow the FDA rules.  Company has a relationship to physician and can market the product only how the FDA says it can–for particular use, and label must say so.
b)    Physician has a responsibility (ethical, though not mandated) to notify the FDA if a patient has a problem with the drug.
c)    Patient has a relationship with the physician.  Essentially every device that is implanted in the body, has a number in the registry.  The doctor can then notify the company when that device is defective, etc.
d)    FDA is not mandated to do this, but occasionally, it will notify doctors itself, through journals, mail-outs, etc. about the effects of the drug.
e)    Company may through hard advertising get information to the patient.
f)    Legally, the problem is what duty does the company have to patient, and not physician?
(1)    In general, the company is shielded from the company – Learned Intermediary Doctrine.  See In re Norplant Contraceptive