Confessions of an Opium Eater
Starring Vincent Price, Linda Ho, Richard Loo, June Kyoto Lu, Philip Ahn, Yvonne Moray, Caroline Kido, Terence de Marney, John Fujioka, Angelo Rossitto
It's a horror and drama movie, and has a rating of 6.2 out of 10 from Imdb which is usually fine for this kind of movie.
Watch it here
Not found streaming from Italy.