Thirst  (1979)

Theatrical Release Information:
Thirst

This cold-blooded, thinly wrought horror film has a warm-blooded theme -- the regular imbibing of said substance by a certifiably crazy cult. Kate Davis (Chantal Contouri) is slowly drawn into this cult against her (and everyone else's) better judgment. Once involved, she discovers that they have sanitized, hospital-like centers where red-blooded individuals are kept zoned out by tranquilizers. Otherwise they might have some objection or another to being essentially imprisoned and immobilized in order to supply blood on demand. In cases where the supply source is particularly popular with one of the cult members, then complete exsanguination is ordered. Even the slightest hint at humor, levity of any kind coming from any direction, might have balanced the weak plot and one-dimensional characters by covertly acknowledging their limitations. ~ Eleanor Mannikka, All Movie Guide