the use of oxycodone at work

I was wanting to know if you could help me. My arm was crushed in a machine at work its not broke but I have muscle and tissue damage. My main concern is that when I went back to work last Tuesday the operator I was working with told me he had been taking his script of oxycodone every day. I wanted him pulled off the machine but my lead said he knew that Larry was on the scripts and he was okay to work on the machine. When my supervisor can back from his weekend I went to him with the same concern he said that he knew larry was on them just not that he was taking them on the clock, yet he had done fine on them so far but now that I was hurt he has determined that Larry is not making good choices while on the meds and he will consider not letting him run machinery and forklifts.