Meds and Measuring Spoons: A Recipe for Error

Kitchen measuring spoons, while ideal for churning out batches of cookies and cupcakes, aren’t appropriate for measuring medicine, and new research confirms the practice can yield wildly inconsistent doses.

Although pharmacists are no doubt aware of the dangers associated with the use of inaccurate measuring devices, many patients continue to use them for pouring liquid medicines.

“This is something taught to pharmacists, but it still happens in practice a lot,” said Jeff Prescott, PharmD, RPh, Pharmacy Times Director of Scientific Content.

The new findings, published in the August issue of the International Journal of Clinical Practice, may provide ammunition for pharmacists in counseling their patients on proper administration techniques.

Researchers tracked down calibrated teaspoons and tablespoons from 25 household kitchens—120 spoons in total—and studied variations between them. Teaspoon volume ranged from as little as 2.4 mL to as much as 7.3 mL. Tablespoon volume was equally inconsistent, ranging from 6.7 mL to 13.4 mL.

These variations could have severe implications for medication dosing, explained lead investigator Matthew Falagas, MD, director of the Alfa Institute of Biomedical Sciences in Athens, Greece. "A parent using one of the biggest domestic teaspoons would be giving their child 192% more medicine than a parent using the smallest teaspoon, and the difference was 100% for the tablespoons," he said.

The problem is exacerbated by medication instructions for many liquid medicines, according to Prescott. "Directions for liquids are almost always given in teaspoons or tablespoons,” he said. “While the intent and rationale is good, there's a lot of room for error.”