What's in a teaspoon? Underdosing with acetaminophen in family practice.

A study was made of 100 paediatric encounters in which an accompanying parent stated that the child had been given acetaminophen syrup during the preceding 24 hours. In 80% of cases a household teaspoon had been used to determine the amount of medication required. The volumes of these spoons were measured using a syringe. The range was from 1.5 to 5 cm3 with 79% containing 2 to 3 cm3. The mean volume was 2.95 cm3 (SD 0.79) and the median was 2.5 cm3. The mean dose administered was 62% of that recommended when the calculation was made according to age and 64% according to body weight. Much of the underdosing observed was due to parents' assumption that a household teaspoon contains 5 cm3 of acetaminophen syrup and also to a failure to correct for advancing age and increasing weight.