Mechanisms of psychotropic drug action L7 Flashcards
4 mental illnesses
Schizophrenia
Depression
Bipolar disorder
Anxiety disorder
what is Schizophrenia
relapsing and remitting illness characterised by positive and negative symptoms
what is depression
a syndrome- a collection of several symptoms occurring together
depression symptoms
low mood reduced enjoyment fatigue sleep appetite loss
bipolar disorder=
episodes of depression
manic episodes
anxiety disorder=
excessive fear and associated physical response
4 neurotransmitters
Dopamine
Noradrenaline
Serotonin
GABA
4 dopamine pathways
mesolimbic
mesocortical
nigrostriatal
tubero-infundibular
mesolimbic=
reinforcement reward
mesocortical=
planning
nigrostriatal=
intiation and control of movement
tubero-infundibular=
hypothalamus to pituitary- dopamine inhibits prolactin release from pituitary gland (breast milk)
Noradrenaline released by
neurones in locus coeruleus in brainstem
what does noradrenaline influence
sleep, wakefulness, attention, feeding
serotonin is also called
5-HT
where is serotonin released from
Raphe nuclei
what does serotonin mediate
Sleep, mood, emotional behaviour
GABA released by
inhibitory neurones all around the CNS
3 antipsychotics
Olanzapine
Haloperidol
Risperidone
what do antipsychotics do
antagonise D2 receptors in the mesolimbic and mesocortical areas
what do Antipsychotics treat
Schizophrenia
side effects pathways of D2 antagonists (2)
nigrostriatal= extrapyramidal side effects Tubuloinfundibular= excess prolactin
first generation antipsychotics=
haloperidol
second generation antipsychotics
Risperidone
Olanzapine
positive of second generation antipsychotics
have less extrapyramidal side effects
disadvantage of second generation antipsychotics
more metabolic and cardiac side effects
what can make people taking antipsychotics for schizophrenia lose 20 years of life
Increased cardiovascular risk
3 type of antidepressant
Tricyclic
SSRIs
MAOIs
what do tricyclic antidepressant do
blocks Noradrenaline and serotonin reuptake transporters at synapse
e.g of tricyclic antidepressant (2)
Amitriptyline
Lofepramine
what are SSRIs
selective serotonin reuptake inhibitors
e.g of SSRI (2)
citalopram
Fluxoetine
SSRIs used for
depression and anxiety
side effects of SSRIs (3)
Nausea/ vomitting
Sexual dysfunction
increased suicidal ideation
what are MAOIs
Mono-amine oxidase inhibitors
what do MAOIs increased the availability of in the synapse
Serotonin
Dopamine
Noradrenaline
2 e.gs of MAOIs
Phenelzine
Meclobemide
what can produce a hypertensive crisis on MAOIs
foods rich in Tyramine (cheese)
what does tyramine do
precipitates Noradrenaline release from vesicles
what chemical can prevent further episodes of depression and mania in people with bipolar
Lithium
side effects with normal levels of lithium
weight gain
fine tremor
more urine
Benzodiazepines=
GABA agonists
e.g of Benzodiazepines (3)
Diazepam
Lorazepam
Themazepam
use of benzodiazepines
anxiety and sleeping
what is the dopamine hypothesis in schizophrenia
schizophrenia is the result of dopamine hyperactivity in the brain (mesolimbic tract)
evidence against dopamine hypothesis in schizophrenia
dopamine antagonists take 2 weeks to have effect but neurotransmission effects are immediate
other neurotransmitters involved
monoamine theory of depression=
depression as a result of a deficiency in brain monamine neurotransmission
monoamine=
serotonin
dopamine
Noradrenaline
