A Very Good Friend Is Post-op. I Am 2 Hours

A very good friend is post-op. I am 2 hours away and helping his best friend via text. Scott, the patient, had fluid drained from his chest which was due to his all of his right ribs being broken in an auto accident on Sept 11 of this year. They gave him 2 shots just before leaving the V.A. my guess is Demerol and Morphine. When does the Demerol start wearing off? and when does the Morphine start wearing off? so that we/he can administer Motrin?