Neuroleptics Flashcards
Antipsychotics for
Decreased thought disorders
Decreased perceptual disordes
Variable effect on emotional disturbance and motor behaviour
Underlying cause not stopped
Dopamine
Inc. dopaminergic transmission= psychosis
Inc Dopamine Causes
Levodopa for Parkinsons
Amphetamines displace dopamine
MAOI
Cocaine inhibits reuptake
Other Dopaminergic Agents
Alpha-methyl tyrosine reduces synthesis
Reserpine depletes vesicles
Dopamine blockers- haloperidol (may potentiate effects by blocking autoreceptors)
Blockade of D2
Antipsychotics have D2 affinity
Acute antagonism: Inc DA turnover, inc neuron firing
Delayed alteration of receptor responsiveness
Downregulation results in long term firing decrease
Motor Effects
Parkinsonism- rigidity, slowing of vol movement, tremor
Akathisia- restlessness
Acute dystonia/ dyskinesia
Tardive dyskinesia- even after discontinuation
Malignant Neuroleptic Syndrome
Excessive dopamine blockade Altered BP and HR Muscle rigidity Hyperthermia Treat with Bromocriptine or muscle relaxants
Endocrine Effects
Inc Prolactin Hyperprolactinaemia Galactorrhoea, amenorrhoea, loss of libido Weight gain Withdrawal symptoms
Other effects
Muscarinic, adrenergic, serotonergic, histamine receptors affect BP etc
Clozapine
Positive and negative symptoms reduced
Alpha1>5-HT2A>D1,D2
Strong risk of seizure
Agranulocytosis
Risperidone
5-HT2A>D2
Aripiprazole
Partial agonist at D2, 5-HT2C/1A
Typical Neuroleptics
Chlorpromazine
Fluphenazine
Haloperidol
Mesolimbic pathway
Action on positive symptoms
Mesocortical
Negative and cognitive symptoms
