My Husband Has A Cdl License Issued From Indiana. He

My husband has a cdl license issued from Indiana. He has severe pain in his hip which may be due to car accident injuries 35 plus years ago in which arthritis has set in. His Dr. gave him a prescription for TramadolP HCL 50mg. She told him that he can still legally take this and still drive truck. The pharmacist said he could only take it once a day at bed time. My question is.....Since most pain killers are NOT ok to take if you drive with a cdl is Tramadol ok with DOT