Changes

This group of antibiotics function by binding to the cell membrane and then making it permeable. This will lead to swelling of the cell and then apoptosis, resulting in the antibiotic being very bactericidal and a concentration dependent killer. As they are cationic basic proteins they also act like detergents.  

This group of antibiotics function by binding to the cell membrane and then making it permeable. This will lead to swelling of the cell and then apoptosis, resulting in the antibiotic being very bactericidal and a concentration dependent killer. As they are cationic basic proteins they also act like detergents.  

This group of antiobiotics also have another interesting function; they are capable of binding to bacterial endotoxin (LPS) and therefore neutralise. It is this secondary function, which is often why vets use these antibiotic as they are very useful in treating animals with '''endotoxic shock'''.

This group of antibiotics also have another interesting function; they are capable of binding to bacterial endotoxin (LPS) and therefore neutralising it. It is this secondary function, which is often why vets use these antibiotic as they are very useful in treating animals with '''endotoxic shock'''.

==Spectrum of Activity==

==Spectrum of Activity==

* Systemic use can lead to nephrotoxicity, especially in dogs.

* Systemic use can lead to nephrotoxicity, especially in dogs.

* '''Must not use in renal failure patients''' - as will accumulate in the kidney.

* '''Must not use in renal failure patients''' - as will accumulate in the kidney.

* In man it has been known to be neurotoxix and have neuromuscular blocking effects.

* In man it has been known to be neurotoxic and have neuromuscular blocking effects.

* If sulphate salts are used in the drug preperation, pain and necrosis can occur at the injection site.

* If sulphate salts are used in the drug preperation, pain and necrosis can occur at the injection site.