Is it permissible for a Muslim to eat with a Muslim who takes pills and drugs, or is it not permissible to eat with him, especially if he is one's neighbour? Is it permissible to speak to him or not? What should we do in this situation?
Praise be to Allaah.
If you are able to denounce their evil action and you hope that they will respond, then sit with them in order to advise them and tell them not to do that evil action, and enjoin what is good, in the hope that Allaah will bring about good through you. If they respond, then praise be to Allaah, otherwise withdraw from them.