Sedatives (year 2) Flashcards
what is the effects of a low dose of a sedative?
calm and drowsy (not very responsive but can be roused)
what is the effect of a high dose of a sedative?
sleep (can be roused)
what is the effect of a low dose of a tranquilliser?
calm but alert/responsive (can respond to stimuli but not bothered by them)
what is the effect of a high dose of a tranquilliser?
catalepsy (altered state of consciousness)
what is the effect an anxiolytic?
calm with altered stimuli response (normally stressful situations aren’t stressful)
what effects does a neuroleptic specifically relate to?
specific effects of phenothiazine or butyrophenones in the CNS
what is meant by a neuroleptanalgesia?
effects of combining opioids with a neuroleptic
what are the main classes of sedative? (4)
alpha2 agonist
phenothiazine
butyrophenones
benzodiazepines
what is the effect of pre-synaptic alpha2 receptors stimulation?
sympatholysis
what is the effect of post-synaptic alpha2 receptors stimulation?
sympathomimemesis
what is the endogenous neurotransmitter that binds to alpha2 receptors?
noradrenaline
where are most of the alpha2 receptors in the periphery?
post-synaptic (sympathomimetic)
where are most of the alpha2 receptors in the CNS?
pre-synaptic (sympatholytic)
how can alpha2 agonists be administered?
inject
oral
what are the names of the alpha2 agonists, in order of shortest to longest lasting? (5)
xylazine detomidine romifidine medetomidine dexmedetomidine
what are the main effects of alpha2 agonists? (3)
sedation
analgesia
muscle relaxation
how do alpha2 agonists cause analgesia?
inhibit substance P release in dorsal horns of spinal cord
what are some side effects of alpha2 agonists?
vasoconstriction diuresis hyperglycaemia muscle relaxation sweating
is there an antagonist available for the alpha2 agonists?
yes (atipamezole)
what is the licensed phenothiazine?
acepromazine (ACP)
what effects do phenothiazines have on receptors?
antagonism them
what receptors does acepromazine have high efficacy at? (2)
alpha1 adrenoreceptors
dopamine2 receptors
what is the main effect of phenothiazine when acting on alpha1 adrenoreceptors?
vasodilation
what are the main effects of phenothiazine when acting on dopamine2 receptors? (2)
sedation
muscle relaxation
what receptor does acepromazine have medium efficacy at?
histamine receptors
what are the main effects of phenothiazine when acting on histamine receptors? (2)
anti-emetic
reduce hypersensitivity
what receptors does acepromazine have low efficacy at? (2)
serotonin receptors
muscarinic receptors
what are the main effects of phenothiazine when acting on serotonin receptors?
decreased alertness
what are the main effects of phenothiazine when acting on muscarinic receptors?
reduce parasympathetic tone
how can acepromazine be administered?
inject
oral
what are the main effects of acepromazine? (4)
sedation
muscle relaxation
anti-emetic
anti-histamine
does acepromazine provide analgesia?
no (hence used with opioids)
what are some side effects of phenothiazine?
vasodilation
syncope
long lasting side effects
what receptors does butyrophenones effect?
dopamine2 receptors
histamine receptors
what effect do butyrophenones have on dopamine2 and histamine receptors?
antagonise them
what are the main effects of butyrophenones?
sedation
muscle relaxation
anti-emetic
anti-histamine
do butyrophenones give analgesia?
no
what are some side effects of butyrophenones?
vasodilation
long last side effects
are benzodiazepines agonists or antagonists/
agonists
what receptors do benzodiazepines effect?
GABA receptors
what are some examples of benzodiazepines? (2)
diazepam
midazolam
what are the main effects of benzodiazepines?
sedation (less predictable effect)
muscle relaxation
minimal CV/respiratory side effects
do benzodiazepines give analgesia?
no
is an antagonist available for the benzodiazepines?
yes (flumazenil)
