What are the name of group of drug users?

That is hard to say. Drug users come from every race and nationality, every culture, every gender, and every socioeconomic group. What does change among groups is the choice of drug. Poorer people tend to use drugs that are particularly dangerous or which give the quickest highs. They tend to live for the moment and don't look ahead, as they feel they have nothing to lose, so risks don't matter. Crack is more potent than regular cocaine and tends to cost less. Krocodil is cheaper than heroin, though much more dangerous in terms of risks and side-effects. Middle-class people tend to be more compliant and fearful than members of either extreme in society and may shun illegal drugs, but they may misuse alcohol and legal drugs. The upper class may use illegal drugs, but can afford somewhat safer and purer versions, and they often can afford lawyers and other means to protect their habit.

It also seems the drug of choice and level of desire to use varies with a person's occupation. A trucker may be more likely to abuse amphetamines while on the road, since they see the drugs as a way to help them be more productive, though at home, they may prefer to unwind with alcohol, marijuana, or downers.

Actors and other performers may be more likely to abuse drugs than a number of other groups for a couple of reasons. Many who become performers grew up in abusive homes, and turned to acting or music as a form of escape. As they perform, they force themselves to live in the moment and forget all the trauma they've suffered. But they cannot live in their role forever, and when not performing or between jobs, they may turn to some drug of choice. Now, if they are having current life issues when performing, or they are forced to play a part they don't really want, they may turn to something they think will relax them. Many in the adult entertainment industry use drugs because of the guilt and fear over their roles. Many are trapped in that profession, though in their heart of hearts they hate it. So drugs help them calm down and tune out.