It’s one in the morning, and your teething baby is screaming her head off in pain and frustration. You need to give her a dose of infant acetaminophen, and you need to do it ASAP. The back of the label on the bottle of medication says that she should get a teaspoon: so do you grab a regular spoon from your silverware drawer, or do you dig up the actual measuring spoon from wherever it’s been buried underneath all the other kitchen supplies in the cupboard?
If you went with option A, you’re hardly alone. A recent study showed that nearly half of parents (forty percent) had made a significant error while measuring out a dose of medication for their children. And when were they most likely to make an error? When the dose instructions were written in terms of customary units – like teaspoons and tablespoons – rather than metric ones, like milliliters.
When we read “tablespoon” on a label, our first thought is often of the sort of spoon we literally use at the table. But should that mean a soup spoon, or a dessert spoon, or a coffee spoon, or a melon spoon? At one in the morning, the difference might not seem important, but actually, a soup spoon contains a lot more volume than a coffee spoon does, and a baby getting a dose of medication from one of those might really be getting an overdose.
While milliliters, teaspoons, and tablespoons are the most common units to appear on medication labels, in some cases, even more obscure measurements appear: just how much is a “dram”, and how is a parent supposed to know how to measure it out (at least without logging onto her computer to ask Google for a quick conversion)?
And although many Americans find metric measurements confusing, it’s hard to argue with the fact that there’s no wiggle room on instructions that read “5 milliliters” compared to those that say “1 teaspoon”: the study found that medication errors were twice as likely with customary units compared to metric ones.
Specifying a quantity in milliliters means parents are forced to seek out a dosing syringe or medication cup, rather than grabbing for the nearest utensil at hand – while it’s still possible to give an incorrect dose using one of these tools, by misreading the number scale, for example, the chances are greatly reduced.