There are some drug references in the film where the female protagonist, Karen, is implied to be abusing marijuana.
In one instance, she purchases a pack of marijuana from an elderly man and licks a piece of paper in preparation of a joint. There are, however, no further details as she is later seen smoking from a distance.
Other instances where Karen is implied to be consuming marijuana depict her holding a joint between her fingers and a glowing ember seen inside her vehicle which is parked at a distance.