Patients often do not tell their physicians about over-the-counter (OTC) medications they or their children are taking, and in many cases patients are not aware of the potential side effects of these drugs. One study suggested that at least 50 percent of three-year-olds in the United States have received some type of OTC medication. Simon and Weinkle evaluated the ability of caregivers to accurately measure and administer acetaminophen to children.

A questionnaire was administered to 100 caregivers of children under 12 years of age seen in an emergency department for nonemergent concerns. Mothers represented almost 90 percent of the caregivers. The mean age of the caregivers was 29.0 years, and the mean age of the children was 2.8 years. Eighty-seven percent of the caregivers had graduated from high school.

The caregivers were asked for information about OTC use in the previous two months. They were then given a mock scenario in which they had to determine the correct dose of acetaminophen for their child with a febrile illness. Package labeling was available to the caregivers, as was the child's weight. A dose of 9.0 to 16.5 mg per kg was considered correct. The caregivers were asked to measure the correct dose in a device of their choice, such as a dropper, syringe, teaspoon or measuring cup. The amount was considered to be accurate if it was within 20 percent of the dose that the caregivers stated they intended to give.

Seventy-seven percent of the caregivers stated that they had given OTC medications to their children, most commonly acetaminophen, cough and cold preparations, vitamins and ibuprofen, during the two-month period before the emergency visit. Only 28 percent of the caregivers were aware that OTCs could have adverse effects. Only two caregivers said they would consult their physicians before giving an OTC medication to their children.

During the mock scenario, only 40 percent of the caregivers calculated the correct dose of acetaminophen for their child, although 67 percent accurately measured the dose they stated they intended to give. The actual measured doses ranged from 8 to 210 percent of the stated intended dose. Forty-three percent of the caregivers measured a correct amount of acetaminophen for their child, but one third of these did so strictly by accident because they had calculated an incorrect dose. An underdosage was measured by 48 percent of the caregivers and an overdosage by 9 percent. When the data for calculating and measuring the dose were combined, only 30 percent of the caregivers both determined and measured the correct amount of acetaminophen for their child.

The authors conclude that a significant number of caregivers inaccurately administer OTC products to children. Since 50 percent of emergency room visits are for fever-related concerns, improper use of acetaminophen may contribute to a lack of clinical response and an overuse of emergency room services. The authors also state that primary care physicians need to teach their patients about proper dosing and administration of OTCs and the potential for adverse side effects.