My Partner Was Prescribed Today Oxycodacetamin For Kidney Stone Pain.

My partner was prescribed today oxycodacetamin for kidney stone pain. He is going to have laser surgery tomorrow. He was told to take a pill every 4 hours.... but it is not helping the pain for long....he took a pill an hour ago...now has more pain and he just took another pill ...so 2 pills within one hour....is that safe? If he gets more pain soon, can he take another pill?