You can only offer a explanation of why they should take their medication but thats all you can do. You cannot force adults to do what they do not want to do (whether they have a disability or not) . Refusing to take their medication is their personal choice and they have the right to deny it just like any other adult. A person refusing to take their medication will have to learn the consequences of not taking it. *Bottom line, you have no control over adults they have the right to choose what they want/dont want to do.