I am here for my friend. He is 25 years old and for the past few days, he has been suffering from a severe back pain. Earlier, he had an accident in which he received back injuries. He was taking ibufrofen and paracetamol combination tablet for himself but it didn’t help him much. Now, he has been prescribed a narcotic pain killer called vicodin. I would like to know from you as to what would be an appropriate vicodin dosage for him?