A Taste of Blood (1967)

Mild-mannered Miami businessman John Stone receives a parcel from England containing two old bottles of Slivovitz brandy; upon drinking them both, he becomes a vampire. He uses his newfound vampire powers to keep his wife Helena in a trance as he travels to England to kill the descendants of Van Helsing, who murdered Count Dracula, while Helsing's distant relative Howard Helsing pursues him, intent on putting the reborn vampire to rest for good.