Toxicological barriers to providing better drugs.

The unmet needs of the sick demand that toxicologic requirements do not stifle the rational search for new and better remedies. A number of conceptual problems hamper the rational use of toxicological testing. These include: a misplaced confidence in the value of animal testing, a failure to make sophisticated risk-benefit analyses, the proliferation of new tests of uncertain validity, and improperly executed retrospective case control studies. Rugulatory barriers include the ever increasing bureaucratic demand for toxicological testing, the unseemly willingness of regulatory agencies to yield to hysterical or cynical consumer group pressures, the unreasonable demand for "superiority" of new products before the granting of registration, and the temptation to institute expensive but untested post-marketing surveillance schemes. Economic obstacles to new drug development have become formidable, and new demands for toxicologic studies in animals and humans are adding to these problems. Finally, some examples of unwise regulatory decisions involving saccharin, spray adhesives, Depo-Provera, and a new anti-metabolite are given.