My Dad Has Forgotten To Re New His Naproxen Prescription

My dad has forgotten to re new his naproxen prescription for arthritis. He is 76 ,he ran out Wednesday. Today he started with painful ankle joint , then one painful knee joint then the other. I have given him Ibrufen until he can get naproxen tomorrow and rest his joints. He cannot mobilise too painful, now later today he has chill shivers? No other symptoms .