I am a student with a question on a recent prescription for my son. He weighs 36 lbs and was prescribed hydrocodone/acetaminophen (Lortab) oral solution 7 mL q4-6 hrs PRN. I looked up the medication in my drug book and it says that the concentration is "2.5 mg hydrocodone plus 167 mg acetaminophen/5 mL" for the oral solution. Based on my calculations, his correct dosage range is 3.27 - 4.91 mL q 4-6 hrs PRN with a maximum dosage of 5 mL. Am I misunderstanding the information in my drug book? Does someone mind looking it up in their own drug books (if you're not already familiar withe concentration) to verify that my calculations are correct? The doctor wrote the prescription and the pharmacist filled it. Since I'm a student, I keep thinking that surely I'm missing something since the pharmacist filled it?