Changes

Over the years different sub-groups of Penicillins have been developed; this is because many bacteria have developed '''beta-lactamases''' which will therefore reduce the action of the antiobiotic

Over the years different sub-groups of Penicillins have been developed; this is because many bacteria have developed '''beta-lactamases''' which will therefore reduce the action of the antiobiotic

e.g. Penicillin sub-families (all have good activity vs. many obligate anaerobic bacteria)

'''Natural Penicillins''' - benzylpenicillin or Penicillin G

• The first to be discovered, the natural penicillins (benzylpenicillin or Penicillin G) has:

* Narrow spectrum of activity.

• a narrow spectrum of activity, being active against mainly gram positive organisms  

* Active against gram positive organisms, except beta-lactamase producing Staphylococci.  

• failing to kill Staphylococcal organisms (gram positives) if they produced beta-lactamase.

 

• Aminopenicillins (e.g. Amoxycillin) were also synthesised to widen the spectrum of action to include many more gram negative organisms than the natural penicillins.  The aminopenicillins are still susceptible to hydrolysis by beta-lactamase enzymes.

• Aminopenicillins (e.g. Amoxycillin) were also synthesised to widen the spectrum of action to include many more gram negative organisms than the natural penicillins.  The aminopenicillins are still susceptible to hydrolysis by beta-lactamase enzymes.

• Addition of a beta-lactamase inhibitor (Clavulanic acid) broadens the spectrum of most sub-gps.

• Addition of a beta-lactamase inhibitor (Clavulanic acid) broadens the spectrum of most sub-gps.

==Pharmacokinetic Considerations==

==Pharmacokinetic Considerations==