Dark Changeling

A successful, middle-aged psychiatrist tormented by an unquenchable lust for blood...
A vampire serial killer on the rampage...
At the age of forty, Dr. Roger Darvell discovers that he is no ordinary man. He also discovers that vampires exist, and that a few of them kill as wantonly and cruelly as any monster in a horror film.
When a renegade vampire follows Roger from Boston to his new home in Maryland and attacks one of his patients, Roger must come to terms with the newly discovered truth about his heritage. And he must find a way to destroy the killer before his newfound lover becomes the renegade's next victim.