Changes

All the sub-groups behave in the same way pharacokinetically.  

All the sub-groups behave in the same way pharacokinetically.  

They are organic acids, hydrophilic and will ionise at physiological pH. They generally have '''poor oral bioavailability''' as they unstable in acid environments. They have a limited volume of distribution (0.2-0.3l/kg), this means the drug is mainly confined to plasma and interstitial space. As the are lipophilic they can't enter cells and won't cross the blood brain barrier, unless it is damaged. They are readily excreted by the kidneys, via tubular secretion in the proximal convoluted tubule. This results in high concentrations of the drug in urine.

They are organic acids, hydrophilic and will ionise at physiological pH. They generally have '''poor oral bioavailability''' as they unstable in acid environments. They have a limited volume of distribution (0.2-0.3l/kg), this means the drug is mainly confined to plasma and interstitial space. As the are lipophilic they can't enter cells and won't cross the blood brain barrier, unless it is damaged. They have short half-lives of about 0.5 - 1.2 hours. They are readily excreted by the kidneys, via tubular secretion in the proximal convoluted tubule. This results in high concentrations of the drug in urine.

* '''Carboxypenicillins''' - unstable in acid. Route of admin: IM or IV.

* '''Carboxypenicillins''' - unstable in acid. Route of admin: IM or IV.

==Side Effects and Contraindications==

==Side Effects and Contraindications==