Here in the U.S. academic libraries have directories of health care professionals that will provide you with the latest address of any licensed physician, just as Martin-Hubbell for lawyers. Also the American Medical Association Doctor Finder web page
is an excellent source of U.S. physicians. Since you live in Miami, I would recommend that you call the University of Miami's Medical School Library, Louis Clder Memorial Library (305-243-6441) and ask the reference department for the name of a title of a medical directory in Spain. They would more than likely have it in their stacks because it is the type of information medical school officials like to have handy to verify academic credentials, etc. If they don't have it try the University of Florida Medical School library (352-392-0342.
if they can't help,contact a university librarian in Spain and ask if such directories exist and if so what is the title. You may be able to find
more information in medical schools as well: Colegios Médicos en Madrid:
CONSEJO GENERAL DE COLEGIOS DE MÉDICOS
VILLANUEVA, 11 914317780
COLEGIO DE MADRID
SANTA ISABEL, 51 915385100
I found an interesting site called El Medico web page
that lists the web sites of many physicians and has an e-mail click that you might be able to ask your question.