I have an idea: why don't we first extensively test these substances on cells in culture, then on all sorts of different animals. Then we can test them for safety in small numbers of human volunteers (perhaps we can call this phase I). Then test for safety, ideal dose, and efficacy on a larger group of humans in a controlled scientific study (call it phase II perhaps). Then, only if these studies show safety and promise should we test a larger group of volunteers (call it phase III perhaps?) Finally, and only if we know all three prior phases of tests indicate the drug is safe and effective would we allow it to be used clinically. Oh, let's keep monitoring the drug even after it is in use so we can detect and fix any unexpected problems.
Oh, in addition why don't we create an entire field of medical science that focuses on what happens to drugs when they are introduced into the human body? We can call it... pharmacokinetics
Would this type of rigorous testing program adequately address your concerns, Clayton?
By the way- the reason tetanus is so dangerous in a deep puncture wound is because the bacterium is so easily killed by oxygen. Although you've ignored the relevant posts, many organisms are more dangerous when eaten or breathed in than when injected. And many substances are much more quickly absorbed if inhaled than if injected im or sc.
