Children's Medications are Dosed in Milliliters, not Milligrams

Originally posted on Reddit by u/Aurra

I've seen a few inpatient pharmacy stories, but so far I haven't come across any from retail pharmacy.

I'm your standard retail pharmacist. I work at a big chain. I spend my days giving shots, telling patients where the bathroom is, and answering questions from randoms who walked off the street ("Yes, you need to go to the hospital" or "Start with hydrocortisone and take that with you to the doctor in a few days if you don't see any improvement" or "The BOGO on vitamins only applies to bottles from the same brand, you can't mix and match."). Despite this, I really do love my job. I have a personality that is perfect for retail, and it's not an insult if I say it about myself.

This story takes place in 2016. I had been practicing for about a year in a suburban location that was rapidly growing and whose population skewed young. A doctor's office near us, "Town Name Family Medicine," was doing their best to keep up with the increased demand and had hired a few midlevels to keep up with the influx of new patients. I walked into a closing shift and my partner let me know about an issue with a prescription that he had called about and left a message.

The prescription was a pediatric antibiotic. Azithromycin 200 mg/5 mL. Take 22 ml by mouth on day 1, then take 11 ml by mouth on days 2-5. This is almost twice what a grown human would take.

Eventually the NP calls me back. She's confused - no one has ever questioned her dosage before (scary!). I tell her that this is 880 mg of azithromycin on the first day and 440 mg on the next days, and that the usual dose is 500mg followed by 250mg on subsequent days.

She tells me, "Pediatric medicine is dosed on weight in milliliters, not milligrams. This is an appropriate dose."

I stumble a little because she clearly hasn't understood what I meant. "Right...but the milligrams in it are really high. Higher than for an adult."

"It's dosed in milliliters, not milligrams."

"But...there are milligrams in the milliliters. There are 200 mg per 5 ml. That's how the medication is dosed."

"In milliliters. Not milligrams."

This circle continues for a few more rounds. I was not prepared to give a high school chemistry lecture when I arrived at work that day. I raise my voice at a prescriber for the first time in my career, preparing me for months of hydroxychloroquine and ivermectin interactions that I did not know were in my future.

Eventually, the doctor who owned the practice heard the commotion and took the phone from the NP. I explained the situation to her and before I could even finish the sentence, she said "Oh! That's way too high!" I could hear the NP say that this is how she's always done it, and the doctor responded "that's not how we do it here." She gave me a reasonable dose (10 ml day 1, 5 ml days 2-5).

The NP didn't last long at that practice. This wouldn't have been life threatening, but I wonder how many kids' weeks this lady has ruined with her strep throat + diarrhea combo.