Avoid dosing errors: Lose the spoon, go metric

Parents often make dosing errors when giving their children liquid medication, but switching to metric measurements, rather than teaspoons or tablespoons, can help prevent mistakes, according to a recent study. The results support recommendations by professional groups to adopt a milliliter-only standard for dosing liquid medication.

Researchers interviewed 287 English- or Spanish-speaking parents of children aged younger than 9 years after they had given the children liquid medication, most often antibiotics, prescribed at 2 hospital emergency departments. Parents also brought the measuring instruments they’d used to the researchers and showed them the doses they’d given. The study defined a dosing error as not knowing the correct prescribed dose or measuring the dose incorrectly.

About 41% of parents made a mistake in the prescribed dose and more than 39% measured the intended dose incorrectly; 16.7% used a nonstandard measuring device such as a kitchen spoon. Parents who used teaspoon or tablespoon measurements were twice as likely to make a mistake as parents who used milliliter-only measurements. Non–English-speaking parents and parents with low health literacy also were more prone to error.

Fewer than half the prescribed doses were written in milliliters, and the dose on the medicine bottle label often appeared in teaspoons even when the prescription specified milliliters. Although parents who received prescriptions in milliliters usually used a syringe or dosing cup with milliliter markings, about 25% didn’t get such a device with the medication.

Professional organizations, including the American Academy of Pediatrics, and the Food and Drug Administration have advocated for making metric dosing standard. Most recently, the National Council for Prescription Drug Programs recommended listing dosages in milliliters on the labels of prescription liquid medications and providing graduated measuring devices marked in units corresponding to the container label with medicines.

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