Kitchen spoons and liquid medicines don't mix

Researchers asked 195 university students to pour 1 teaspoon (5 ml) of liquid cold medicine, using either a teaspoon, a medicine-sized tablespoon, or a larger tablespoon. The students were then asked to indicate how confident they felt that they had poured the correct 1-teaspoon dosage into the spoon and, as a group they expressed above-average confidence. Researchers then measured for themselves how much each student had poured into the spoons and found that the dosages varied directly with the size of the spoon, and that students over-dosed (roughly 12 percent more medicine) when using the larger spoon and under-dosed (just over 8 percent less) when using the medium spoon. Actually, the participants dosed roughly 8 percent less when using the medium-sized spoon, and roughly 12 percent more when using the larger spoon.

Using kitchen spoons to pour medicine is a common practice. A previous study on medication dosing found that more than 70 percent of households used teaspoons for measuring liquid medication, but most (92 percent) of the participants measured the correct dose when using an oral dosing syringe, which can be used for dispensing medicine to both children and adults.

To be sure you're getting a safe and effective dose of liquid medicine, we advise against using teaspoons and tablespoons, or obviously drinking straight from the bottle (a practice confessed by two of our staffers). Instead use measuring spoons, an oral syringe (available at pharmacies), or dosing cups, especially when treating. And check the markings on the medicine cup to make sure that it measures the dose you need, and that you can see the markings clearly. Most liquid medicines are measured in teaspoons (tsp) and milliliters (ml): 5 ml equals 1 teaspoon (tsp); 15 ml equals 3 teaspoons or 1 tablespoon (TBSP); and 30 ml equals 1 fluid ounce (oz).

—Ginger Skinner

For more on using medicine safely, see the FDA's printable Medicines in My Home* tip sheet, and read our information on avoiding common medication errors and mixups.

*links to PDF