Thirst

Thirst, a 1979 Australian horror film directed by Rod Hardy and starring Chantal Contouri as Kate Davis, follows a woman who is kidnapped by a cult of modern vampires who believe her to be a descendant of Elizabeth Báthory. The Brotherhood, a shadowy organization, has taken her to a hospital-like compound where they clinically "bleed" brainwashed and hypnotised humans, harvest and consume their blood. Kate is horrified by what she sees and refuses to join or take one of the Brotherhood as a mate, leading them to use hallucinogens to break down her resistance.