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Line 22: − + + + − ==Uses==+ − As previously mentioned, propofol can be used as '''both''' induction and maintenance agents. It is useful in patients undergoing caesarean section as it has mininal foetal depression. It also has anticonvulsant properties and so can be used to anaesthetise a seizuring animal when other treatments, such as [[phenothiazines|diazepam]] , have been ineffective. Similarly to [[#barbitutates|thiopental]], propofol reduces intracranial pressure (ICP), so it can also be used in patients with increase ICP. It may be beneficial to use propofol in patients with upper airway obstructive disease due to rapid recovery meaning that airway reflexes are more rapidly recovered.+
→Mechanism of Action
'''Propofol''' is one of the most commonly used injectable anaesthetic agents in small animal practice. It is a ''very short acting'' alkylphenol. It is generally used as a induction agent but can be used for maintenance of anaesthesia via a total intravenous anaesthesia (TIVA) protocol.
'''Propofol''' is one of the most commonly used injectable anaesthetic agents in small animal practice. It is a ''very short acting'' alkylphenol. It is generally used as a induction agent but can be used for maintenance of anaesthesia via a total intravenous anaesthesia (TIVA) protocol.
==Mechanism of Action==
==Mechanism of Action==
Propofol acts upon the GABAa receptors, causing it's activation, similarly to [[#barbituates|thiopental]], although it binds at a different site. This causes increased chloride conductance leading to hyperpolarisation.
Propofol binds to and activates GABA-A receptors, similarly to [[#barbituates|thiopental]], benzodiazepines and alcohol, although it binds at a different site on this complex multi-subunit receptor. GABA is a major inhibitory neurotransmitter in the CNS. Activation of the GABA-A receptor causes increased chloride conductance leading to hyperpolarisation of the postsynaptic neuronal cell membrane, thus inhibiting conductance producing depression of the CNS.
==Pharmacological Considerations==
==Pharmacological Considerations==
===Propofol in Cats===
===Propofol in Cats===
In cats, glucuronide conjugation is reduced, which is require for phenolic compound metabolism. This means that recovery from propofol TIVAs is prolonged in cats and has been known to reduce the packed cell volume (PCV) in some patients. Repeated dosing in cats is also not advisable as it causes significant Heniz body formation as well as anorexia, diarrhoea, facial oedema, and depression.
In cats, glucuronide conjugation is reduced, which is require for phenolic compound metabolism. This means that recovery from propofol TIVAs is prolonged in cats and has been known to reduce the packed cell volume (PCV) in some patients. Repeated dosing in cats is also not advisable as it causes significant Heinz body formation as well as anorexia, diarrhoea, facial oedema, and depression.
==Uses==
As previously mentioned, propofol can be used as '''both''' induction and maintenance agents. It is useful in patients undergoing caesarean section as it has mininal foetal depression. It also has anticonvulsant properties and so can be used to anaesthetise a seizuring animal when other treatments, such as [[phenothiazines|diazepam]] , have been ineffective. Similarly to [[#barbitutates|thiopental]], propofol reduces intracranial pressure (ICP), so it can also be used in patients with increased ICP. It may be beneficial to use propofol in patients with upper airway obstructive disease due to rapid recovery meaning that airway reflexes are more rapidly recovered.
[[Category:Injectable Anaesthetic Agents]]