My Friend Was Involuntarily Committed

My friend, M27 was involuntarily committed 2 nights ago. He went into the hospital because he was having a bad reaction (chest pain, and feeling faint/ about to lose consciousness) to doctor prescribed medication, and they told him he couldn’t leave when he tried to get up to go to work. He continued to try to leave because he was confused on why he couldn’t and the next thing he knows they injected him with something and took him to the psych ward. They told him he could be there for at least 2 weeks.

I need help on how to go about getting him out. He doesn’t have any mental illnesses besides some anxiety and occasional depression. Other than that he is completely healthy and sane. (We’re located in NY)