what makes a drug a "last-resort" drug

[Silvia_84]

Hi all,

 

could you explain to me why the carbapenems (and other antibiotics) are considered last-resort drug?

I am aware that they are used when all the other drugs fail to treat infections but I don't understand why they are the strongest..Do they have more catalytic activity?Do they act with particular molecular mechanisms?Can you explain me please?

 

Any suggestion would be really appreciated.

 

Thanks

[StringJunky]

I'm no expert on this but have you considered that's it's not that they are stronger. The bacterial pathogens have had less opportunity, within the general population, to evolve resistance to these last-resort drugs because they've been prescribed much less. The main cause of antibiotic resistance is overuse in inappropriate circumstances and not completing treatment AFAIK e.g. many people take antibiotics for infleunza-type ailments, when they are not effective for viruses; providing latent, pathogenic, bacterial populations conditions for evolved resistance. Less use is better.

Edited May 11, 2016 by StringJunky

[CharonY]

That is essentially correct. Last resort ABs are usually withheld from common application, in some cases also because administration is not trivial. For example Amikacin, has been around for a long while, but it cannot be administered orally. Also many newer drugs are almost by default last resort ABs as the bacteria are expected not to be resistant against them (yet).

That being said, there are fewer and fewer drugs that are still effective.