Which antibiotic has better effect on killing bacteria?

Question

primadex?

ampicillin?

Ampoxicillin?

give reasons why..

thx

Answer 1

Zeep gave a pretty good detailed answer.  One factor also involved is that many strains of bacteria have become resistant to normal penicillins because the bacteria produce penicillinases ( enzymes that degrade the beta lactam structute in penicillin which is essential for its activity). Some synthetic penicillins have added to them clavulinic acid which inhibits the penicillinase...thus enhancing activity against penicillinase producers . Augmentin TM   is amoxicillin containing clavulinic acid and there are of course generics.

Answer 2

There's no right answer as to which has the best therapeutic effect. It depends a lot on the infection.  I had to google Primadex to see that it was another name for Bactrim (trimethoprim-sulfamethoxazole).

Ampicillin and amoxicillin have virtually identical abilities to kill bacteria; amoxicillin is just absorbed better orally.  They're closely-related penicillins that are bactericidal - kill bacteria.

Primadex is usually bacteriostatic - it stops the growth of bacteria, and then the immune system has to clear those non-growing bacteria. The antibiotic itself doesn't usually kill them.

So, in terms of actually directly killing bacteria, amoxicillin and ampicillin would be the right answer.  In general therapeutic terms, there is no right answer.  For particular infections, amoxicillin might be better for one (strep throat, e.g.), and primadex might be better for another (Pneumocystic prophylaxis in AIDS, e.g.)