L36 Drugs used in mental health disorders II Anti-psych→↑↓”otics

Question 1

Mechanism, Contraindication, S/E of Typical antipsychotics (First generation)

Answer 1

Chlorpromazine Fluphenazine

MoA
block brain dopamine receptors (especially D2 receptors).

Side effects
Extrapyramidal symptoms
→Acute dystonia
→Parkinsonism

Hyperprolactinemia symptoms
→Galactorrhea

→ Drowsiness

Neuroleptic malignant syndrome (NMS)

→Effective against positive signs and
NOT negative signs of psychosis.

Question 2

Mechanism, Contraindication, S/E of Atypical antipsychotics Second generation drugs

Answer 2

iloperidone Paliperidone

→5HT2 receptor binding exceed their
affinity for dopamine D2 receptor
→→Quickly dissociate from D2 receptor
thus reduces side effect

Treat both the negative and positive
signs of psychosis.

Side effects
Metabolic side effects
• Increase risk of high blood sugar
• Elevated lipids and cholesterol
• Increased risk of diabetes
• Severe weight gain (obesity)

Extrapyridmal effects
e.g. Movement disorders
• Hyperprolactinemia
• Neuroleptic malignant syndrome
• Sudden death

Antagonisms of α1 adrenergic receptors
→ reflex tachycardia and postural hypotension.

Antagonism of the muscarinic receptors can produce anticholinergic symptoms, → hyperthermia, tachycardia, mydriasis, dry mouth, constipation, urinary retention.

Antagonism of the histaminergic receptors →primarily sedation and slowness.