∞ generated and posted on 2016.02.20 ∞
Potential to harm target organisms, such as pathogenic bacteria, but somewhat less potential to harm other organisms found in their association, such as ourselves.
The utility of antibiotics stems particularly from their selective toxicity and indeed antibiotics which are not selectively toxic are much less useful. Indeed, the idea of selective toxicity really is a specific instance of what is true with anything that we bring into association with our bodies, or indeed anything that we use in any capacity: Benefits must outweigh costs, often substantially.
Costs in the case of drugs – in addition to actual economy or convenience – are seen as side effects. Selective toxicity thus can be described as effective at inhibiting the growth of target organisms while at the same time producing minimal side effects to ourselves.
Antiseptics and especially disinfectants tend to be much less selectively toxic, which is why we do not use these agents internally or, in the case of most disinfectants, in contact with our bodies at all.
As is true for antibiotics is also true for anti-cancer treatments where substantial utility is gleaned from a potential to harm cancer cells without simultaneously harming non-cancer cells.