Changes in drug action in growing animals

Some results are given from a long-term study of possible changes in drug action in growing animals. It was found that the changes were of different character according to the drug studied, amongst other factors. A non-parallelity in changes of toxic effects and therapeutic effects of some drugs during aging appears to be important. The influence of age on effects in drug interactions is of great interest. All the findings show that it will be very difficult to correct for dose with respect to developmental changes in animals without further pharmacodynamic and pharmacokinetic studies in this field of pharmacology.