Psychiatry

What are typical antipsychotics?

Dopamine D2 receptor antagonists - block mesolimbic pathways (and so positive symptoms)

Extrapyramidal side-effects and hyperprolactinaemia (via tuberoinfundibular blockade) common

Haloperidol, chlorpromazine

What are atypical antipsychotics?

Act on variety of receptors (D2, D3, D4, 5-HT) - blockage of 5-HT may improve negative symptoms

Extrapyramidal side-effects and hyperprolactinaemia less common; are metabolic effects

Clozapine, risperidone, olanzapine

What are extrapyramidal side-effects?

Parkinsonism, acute dystonia, akathisia, tardive dyskinesia

What is Parkinsonism?

Bradykinesia, resting tremor, rigidity

What is acute dystonia?

Sudden onset involuntary muscle contractions that cause abnormal movements and postures; incl. oculogyric crisis (involuntary upward eye movement), torticollis (twisting of neck muscles), trismus (lockjaw)

What is akathisia?

Subjective feeling of restlessness, often with inability to sit still

Typical within first few weeks of typical antipsychotics

What is neuroleptic malignant syndrome (NMS)?

Severe reaction to antipsychotics

Hyperthermia, altered mental status, autonomic dysfunction, generalised muscle rigidity (‘lead pipe’ rigidity)

Can also present with agitation due to the altered mental status

What happens if a patient misses 2 consecutive days of clozapine dose?

Will need to re-titrate the clozapine doses slowly again

If you just continue at same dose then side effects will be worse - blood pressure, drowsiness, dizziness

What monitoring does a patient on antipsyhcotics need?

FBC, U&Es, LFTs

Lipids, weight

Fasting blood glucose, prolactin

Blood pressure

Electrocardiogram

CVD risk assessment