Antipsychotics Flashcards
Antipsychotics
Typical antipsychotics
-Haloperidol & Chlorpromazine
-MOA: Dopamine D2 receptor antagonists, blocking dopaminergic transmission in the mesolimbic pathways
-AEs: Extrapyramidal side-effects & hyperprolactinaemia common
Extrapyramidal side-effects (EPSEs)
Parkinsonism
acute dystonia
sustained muscle contraction (e.g. torticollis, oculogyric crisis)
may be managed with procyclidine
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)
The Medicines and Healthcare products Regulatory Agency has issued specific warnings when antipsychotics are used in elderly patients:
increased risk of stroke
increased risk of venous thromboembolism
Other side-effects
antimuscarinic: dry mouth, blurred vision, urinary retention, constipation
sedation, weight gain
raised prolactin
may result in galactorrhoea
due to inhibition of the dopaminergic tuberoinfundibular pathway
impaired glucose tolerance
neuroleptic malignant syndrome: pyrexia, muscle stiffness
reduced seizure threshold (greater with atypicals)
prolonged QT interval (particularly haloperidol)
Atypical antipsychotics
-Act on a variety of receptors (D2, D3, D4, 5-HT)
-Metabolic effects
