Spoon size influences misdosing of liquid OTCs

Executive Summary

A study that found participants misdose liquid cold medicine depending on the size of the spoon they use supports FDA's and industry's push to standardize measurements and dosing devices. A study by Brian Wansink and Koert van Ittersum at Cornell University in the Jan. 5 Annals of Internal Medicine found consumers who use a medium-sized spoon to measure liquid cold medicine poured an average 8.4 percent less than the prescribed amount, but 11.6 percent more with a larger spoon. They asked 195 university students to pour 1 teaspoon of cold medicine in a measuring spoon and then pour 1 teaspoon in a medium spoon and a large spoon and rate how confident they were that they poured the correct amount. Participants had an above-average confidence they accurately poured the amount. While the difference may seem minimal, "the dosing error is likely to accumulate among fatigued patients who are medicating themselves every four to eight hours for several days," the researchers say. The risk of misdosing liquid medicines with the wrong measuring device prompted FDA to recommend in recent guidance that firms "secure the dosage delivery device to the drug product" (1"The Tan Sheet" Nov. 9, 2009). The agency notes in its Safe Use Initiative that misdosing liquid OTC products is worrisome because children often use them. The Consumer Healthcare Products Association also recommends standardized labeling of OTC oral liquids to prevent misdosing (2"The Tan Sheet" Dec. 7, 2009)