Children are not miniature adults, and drugs intended to be consumed by adults aren’t necessarily good medicine for kids. A blog post on the FDA Voice website explains why.

Lynne Yao, associate director, Pediatric and Maternal Health Staff in the FDA’s Center for Drug Evaluation and Research, reminds readers that some drugs work differently according to where in the human maturation the person taking them is. Efficacy is one issue for children taking drugs intended for adults, and safety is another. “That’s why products that are used in children,” Yao says, “must be studied in children."

Two recently reauthorized laws promote that effort. The carrot is the Best Pharmaceuticals for Children Act (BPCA), which offers drug companies six months more of marketing exclusivity if they conduct FDA-requested pediatric studies. The stick is the Pediatric Research Equity Act (PREA), which requires some drugs developed for adults to be studied in children. The studies must be conducted with the same drug and for the same use for which they were approved in adults.

As Yao notes, before BPCA and PREA became law, more than 8 in 10 drugs approved for adult use were being used in children, even though their safety and effectiveness had not been established in children. Today, it’s about 5 in 10. And now that both acts have been reauthorized with additional FDA powers, the hope is that the disparity will shrink farther.

Under PREA, FDA may waive studies in children if they aren’t necessary, such as a drug prescribed for a disease only adults contract, like prostate cancer.

When Congress reauthorized PREA last year as part of the Food and Drug Administration Safety and Innovation Act (FDASIA), it gave the FDA additional authority. The agency may grant extensions for deferred pediatric studies at a sponsor’s request if there is good cause; say, the manufacturer has tried but failed (so far) to recruit a sufficient number of pediatric patients to complete the study.

Sometimes the FDA allowed a deferral and still the deadline was missed, so now, if a sponsor fails to seek or obtain a deferral extension, fails to submit deferred pediatric studies by the final due date agreed to with FDA or fails to request approval for a required pediatric formulation, the FDA will send a noncompliance letter to the company and publish it on the web.

The first such “we warned you” noncompliance letters were published last month, along with the manufacturers’ responses. You can track this show-and-tell at the FDA’s public page here. Among the early letters and responses are those concerning an intravenous form of Protonix, a drug to reduce gastric acid made by Pfizer, and Renvela, taken by people with chronic kidney disease, made by Sanofi.

Other drugs on the tardy-testing list include allergy, anaphylaxis and blood pressure medications, all of which are prescribed for children.

As noted on AboutLawsuits.com, however, it’s unclear whether these laws and the transparency of noncompliance give the FDA enough muscle to compel compliance.

The letters state that the companies failed to satisfy their obligations to conduct pediatric studies on approved children’s medications, but as AboutLawsuits points out, the FDA may label a drug misbranded only if the studies are not conducted. It may not withdraw approval. It’s unclear if the agency can levy fines or take any other punitive actions beyond the public scolding.

Some of the drugs on the letter list were supposed to have been tested on children as long as seven years ago. In each case, AboutLawsuits says, the companies failed to apply for an extension. Although the letters give the companies 45 days to respond, they are silent about any consequences or what happens next.

The FDA’s renewed interest in the safety of pediatric drugs follows recent studies depicting how some medications used on adults have detrimental effects in children.

For example, a study published last month in JAMA Psychiatry found that children who use antipsychotic medications such as Risperdal and Zyprexa had three times the risk of developing type 2 diabetes during the first year of use. That study was the result of a government investigation into the increasing number of children who were prescribed antipsychotic medications intended for adults.

If your child is prescribed a medication, ask the doctor if it has been tested in that form and in that dose for children. If not, or if he or she doesn’t know, consult Medline Plus, the government’s drug information clearing house, and the manufacturer’s website.