Many overdoses have been linked to confusing labels and misleading measuring devices. As a result, the Food and Drug Administration (FDA) issued voluntary guidelines to drug makers late last year, recommending ways to simplify the dosing of liquid medicines. Key recommendations included providing measuring devices with all products, plus making sure the devices display only necessary markings and don’t hold more than the largest described dose.

It's not yet clear how widely these recommendations have been adopted. But a newly released study illustrates why such changes are vital—and also what pitfalls parents should watch out for when dispensing liquid medications to their children. 

The researchers did a yearlong review, ending in October 2009, of the 200 top-selling over-the-counter liquid medicines for children under age 12. Their review encompassed an extensive range of products, including allergy, cold, cough, gastrointestinal and pain-relieving medications.

Of these products, 148 (74 percent), included a measuring device. However, nearly all of these devices (146) had markings that were inconsistent with the medication's dosing instructions. For example, 36 had missing markings and 120 had markings not relevant to the instructions (for instance, they included units of measurement not mentioned in the instructions, such as drams).

The products used a wide range of dosing units, including milliliters, teaspoons, tablespoons, cubic centimeters, ounces and drams. And 65 percent of the medicines included two or more of these measurements. There was also variation in how the measurements were abbreviated (for example, mL, mls and ML for milliliters), and more than 80 percent of the products didn't define one or more of their abbreviations.

Undoubtedly some drug companies have made improvements since the researchers collected their data and the FDA issued its recommendations. Still, the study vividly illustrates why many parents feel perplexed when giving their children liquid medicines. Reading the study, I was reminded of my own recent confusion when peering at a measuring cup for acetaminophen, with barely legible embossed doses in both "tsp" and "ml." It was almost impossible to see which measuring line went with which type of dose, so much information was packed on the tiny cup.

What you need to know. This study provides a reminder that caution and close attention are necessary when giving a child liquid medication. Although the measuring devices included with these products can be confusing, it's important to use them, rather than resorting to kitchen spoons, which vary in size and are unreliable measuring tools. And if you have any dosing questions, be sure to ask your pharmacist or doctor.

—Sophie Ramsey, patient editor, BMJ Group

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