Explain the concept of selective toxicity.

Question

What will be an ideal response?

Answer 1

Selective toxicity is the underlying principle supporting Ehrlich's idea of the "magic bullet." This simply means that the most effective antimicrobial drugs are those that target some difference in a cellular structure or metabolic process between the host/patient cell and the target microbe. Conversely, the more similar the host cell and the microbe are, the harder it is to selectively attack just the microbe. Drugs that do not differentiate very well between types of cells are generally more toxic to the host than those that are more selective. This is most striking in the case of antiviral drugs, which are generally poor magic bullets because the virus is dependent on the host cell for all aspects of its growth. Those drugs that successfully inactivate the virus sometimes also end up damaging or even killing the cell.