Antipsychotics

Question 1

Lithium

• MoA
• Side effects
• Monitoring

Answer 1

MoA: Inhibition of dopamine and promotion of GABA (not well understood)

Side effects:
GI disturbance, nephrotoxicity, T wave flattening/inversion, hyperparathyroidism, leucocytosis
diabetes insipidus,** idiopathic intracranial hypertension, tremor (fine)**, hypothyroidism, increased weight, metallic taste

Monitoring:
Narrow therapeutic range -blood levels checked weekly upon dose change and every three months thereafter. Should be measured 12 hours after last dose. Thyroid and renal function measured every six months. Alert card should be issued.

Question 2

Typical antipsychotics

• Examples
• MoA
• Side effects
• Monitoring

Answer 2

Examples:
Haloperidol, chlorpromazine
MoA:
Dopamine recptor (D2) antagonists
Side effects:
Hyperprolactinemia, extra-pyramidal side effects (e.g. parkinsonism, acute dystonia, akathisia, tardive dyskinesia), increased risk of stroke/DVT (elderly patients, antimuscarinic effects, imparied glucose tolerance, neuroleptic malignant syndrome, reduced seizure threshold, prolonged QT interval

Monitoring:
FBCs/U&Es/LFTs (annual), lipids/weight/fasting blood glucose/prolactin (annual), cardiovascular risk assessment (annual), ECG and blood pressure (baseline)

Question 3

Atypical antipsychotics

• Examples
• MoA
• Side effects
• Monitoring
• Extra info

Answer 3

Examples:
Clozapine, risperidone, olanzapine, apriprazole

MoA:
Act on a variety of receptors (D2, D3, D4, 5-HT)

Side effects

Extra-pyramidal side effects (but less likely than with typical antipsychotics), weight gain, agranulocytosis (clozapine), increased risk of stroke/DVT (elderly patients), dyslipidemia (olanzapine)

Monitoring:
FBCs/U&Es/LFTs (annual), lipids/weight/fasting blood glucose/prolactin (annual), cardiovascular risk assessment (annual), ECG and blood pressure (baseline)

Extra info:
Clozapine and olanzapine have worst side effect profiles, apriprazole has best side effect profile