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?
Apr 9, '12
unfortunately there is no standard concentration of hydrocodone/acetaminophenelixir; the concentration is going to vary depending upon manufacturer. an internet search revealed sixconcentrations, and it is possible that there are more. this is why it is important to use thedose (mg) rather than the volume (ml) with pediatric medications.
[font="trebuchet ms"]yourdrug book should provide you with the appropriate pediatric dose in mg/kg, and theconcentration dispensed should be on the bottle. if you still have questions or concerns afteryou review both of these, you should contact either your pediatrician or thedispensing pharmacy for clarification.
Apr 9, '12
Thanks for the response. Yes, I had looked it up in Davis' Drug Guide and it recommended 0.14 mg/kg q 4-6 h (which would put him at 2.29 mg (this is roughly about 4.58 mL since the concentration is 2.5 mg/5 mL). Epocrates lists a range of 0.10-0.15 mg/kg q 4-6 h (which is where I got the range of 3.27-4.91 mL). Lexi-Comp recommends 0.1-0.2 mg/kg/dose which still makes the maximum dose less than 7 mL (it's 6.55 mL).
I see what you're saying about there not being an established standard concentration for this medication....hmmm. I gave him 5 mL q 6 hrs x 2 today and he seemed to do all right. It's difficult to assess whether I should be giving him the full 7 mL, however. He's not acting like he's in a lot of pain, only mild-moderate, but I don't want the pain to escalate either because I'm under-dosing him...( I understand it's better to stay on top of the pain so it doesn't get out of hand).
Before doing all of this research, I checked the bottle for a concentration, but could not locate one. I was surprised by that. So I was basing my calculations on the concentration listed in the drug book. I will call the pharmacy and verify. Thanks.
Apr 9, '12
Your question needs to be asked to your doctor or pharmacy. We are unable to offer medical advice under the terms of service.
Must Read Topics