Simply put, the drug inhibits an enzyme that HIV must have to multiply. From preliminary adult results, it's more potent by about a factor of 10. The drugs, touted for virtually eliminating the virus from adults taking them, reached the trial stage in children some nine months after initial results from the adult studies were reported, about two years after protease inhibitors first became available for study in adults. The lag time frustrates pediatric specialists, but they say a cascade of issues accounts for the slow development of pediatric therapy. It's a conglomeration of factors.
Pharmaceutical companies have trouble making the drugs into liquids that are palatable.
While McKinney thinks some drug companies drag when it comes to work on pediatric formulations, he said low economic incentive isn't the only barrier to development. There's a market factor, of course, but there are some companies that have legitimately tried. Merck has probably spent millions trying to develop a pediatric version of their drug. Burroughs Wellcome also moved AZT to the pediatric arena relatively early, Katz added. Sheer numbers play another part in the slow move of medications from adult to pediatric trials.