Sleeping pill wakes up comatose patient

Hi! I have a friend who just recently had a high blood stroke [that was Oct 17]. The attending physician said his BP was 300 when he was rushed ct to the hospital. He is still breathing when his roommates found him in his room but he is already unconscious and he urinated on his bed and had a vomit when he was found in his room. Doctor needs to give operation coz there are many blood clots in his brain and they gave him 24hours to wake up and if he will not wake up, he might stay in the hospital for long bec he is in deep comatose stage. I have read about this Zolpidem phenomena and I'm just curious if this is really proven and will be effective to use for my friend also or is it only applicable to some situations? Pls answer my question whoever knows about this Zolpidem pill. Thanks a lot and more power to your website!