You would have to first make the case that there IS a connection between people giving money or goods to those in need and overdoses and/or booze-fueled violent acts, as it is far from clear that there is any actual connection. 
I could give a hungry guy a sandwich and he could choke on it. Is this a rationalization for never making a sandwich for someone? I'm not any more responsible for what someone does with money or legal goods given than an employer is responsible for what an employee does with her earnings, or than the state is when it provides food assistance. People who receive SNAP can buy food and then use disposable income to purchase alcohol. That doesn't make the state responsible for anyone's actions.