Anti psychotics Flashcards
How to anti psychotics work?
Antipsychotics act as dopamine D2 receptor antagonists, blocking dopaminergic transmission in the mesolimbic pathways.
Name 3 x extra pyramidal side effects of anti psychotics
- Parkinsonism
- Acute dystonia
- Akathisia
- Tardive dyskinesia
acute dystonia
Involuntary sustained muscular contractions or spasms, often of the neck (spasmodic torticollis)
Clenched jaw (trismus)
Protruding tongue
Eyes roll upwards (oculogyric crisis)
These features happen more in young men and will usually occur within 72 hours of the beginning of treatment
akathisia
severe restlessness
tardive dyskinesia
- late onset of choreoathetoid movements, abnormal, involuntary, may occur in 40% of patients, may be irreversible,
- most common is chewing and pouting of jaw
- No treatment to stop it
Name some antimuscarinic side effects
dry mouth blurred vision urinary retention constipation sedation weight gain
Endocrine side effects on antipsychotics?
raised prolactin: galactorrhoea, impaired glucose tolerance
Anti psychotic induced emergecy
neuroleptic malignant syndrome: pyrexia, muscle stiffness
Name two other side effects of anti psychotics
reduced seizure threshold (greater with atypicals)
sprolonged QT interval (particularly haloperidol)
What is the main advantage of atypical antipsychotics?
No extra pyramidal side effect
What are atypical antipsychotics used first line in?
Schizophrenia
Name 3 anti psychotics
clozapine
olanzapine
risperidone
Name two major side effects of olanzopine
higher risk of dyslipidemia and obesity
What is the indication for clozapine use?
only be used in patients resistant to other antipsychotic medication.
Why is full blood count monitoring required in clozapine?
agranulocytosis (1%), neutropaenia (3%)
Which patients is clozapine contra indicated in?
Epileptic patients because it reduced the seizure threshold
What are the commonly used first generation (typical) antipsychotic agents?
Chlorpromazine
Haloperidol
What are the commonly used second generation (atypical) antipsychotic agents?
Clozapine
Olanzapine
Quetiapine
Risperidone
What is the primary mechanism of action of clozapine when used as an antipsychotic?
Serotonin (5HT-2) antagonist and D4 receptor antagonist
It is also a weak agonist of D2 receptors.
What are the main side effects of the antipsychotic medications as a result of D2 receptor blocking?
Extrapyramidal side effects
Hyperprolactinaemia
What are the features of Parkinsonian syndrome, an extrapyramidal side effect of antipsychotic agents?
Muscular rigidity
Bradykinesia
Resting tremor
Why is it particularly important to warn smokers about clozapine?
moking induces P450 enzymes which means that doses for smokers will often be higher than for non-smokers. This is relevant if the smoker decides to stop smoking without warning their doctor.
