You wouldn’t ask a toddler to wear an adult’s shoes or to chow down its dad’s caloric intake. That’s why clothes, menu portions, even video lengths are adapted to the diminutive sizes appropriate to young children. Yet all too often, medicines are tested in adults and then dispensed in what amounts to an almost one-size-fits-all approach.

Sure, cough-syrup labels recommend that the number of teaspoons administered should be loosely based a patient’s weight. Yet the efficacy of medicine doesn’t necessarily scale with weight alone. It may relate to breathing rate or blood volume, which in children may not scale up or down proportionately with height or weight. Similarly, a therapy’s benefit may scale with the size of an organ — one that may fail to grow much prior to puberty, or with the production of some breakdown enzyme that doesn’t get revved up until a child is at least 6 years old.

One timely example came to light last week involving Vicks VapoRub. It turns out that the mucus buildup fostered by inhaling Vicks vapors may disproportionately risk closing off a young child’s airways, not only because those airways are far narrower than in adults to start with, but also because the walls of major airways in babies are flimsier — less rigid.

For such reasons, pediatricians have reiterated until they’re blue in the face that children are not just small adults.

The pharmaceutical industry, however, has tended to treat children as if they were merely light-weight grown-ups. Or ignored youngsters entirely. According to the World Health Organization, “More than 50 percent of medicines prescribed for children have either not been developed specifically for children or have not been proven to be effective and safe for their use.”

“Children are suffering and dying from diseases we can treat, and yet we lack the critical evidence needed to deliver appropriate effective, affordable medicines that might save them,” argues Carissa Etienne, Assistant Director-General for WHO in Geneva, Switzerland. As such, she contends, “We must take the guess work out of medicines for children.”

In has stepped wealthy benefactors: Bill and Melinda Gates (of Microsoft fame). WHO announced today that their foundation has just donated $9.7 million to work with the United Nations Children’s Fund — better known as UNICEF — to conduct research on establishing child-size dispensing rates for critical medicines. They’re especially needed for treating diarrheal diseases. About 160 children around the world every hour die from such diseases. Currently few medicines outside the developed world have been formulated to successfully treat them.

Although it’s great that the Gates Foundation has stepped forward, the travesty is that the world’s pharmaceutical firms and health agencies didn’t beat them to the punch.

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.

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