Antipsychotics

1st vs 2nd Generation Antipsychotics

1st Gen (Typical)

• Chlorpromazine (Largactil):

  • Low potency → more sedation and anticholinergic effects, fewer EPSE

• Haloperidol:

  • High potency → less sedation, more EPSE

2nd Gen (Atypical)

• Aripiprazole: Fewer metabolic side effects, minimal weight gain/diabetes risk

• Olanzapine: Highest metabolic risk (weight gain, diabetes, hyperlipidaemia); minimal hyperprolactinaemia

• Risperidone/Paliperidone: Most likely to cause hyperprolactinaemia (galactorrhoea, menstrual irregularities)

• Clozapine: Superior in treatment-resistant schizophrenia; agranulocytosis risk → regular blood monitoring

• Quetiapine: Low EPSE risk; often used for sedation

Monitoring of Side Effects

1. Metabolic

• At Every Visit: Weight, BMI, waist circumference

• Annually: Blood pressure, fasting glucose, lipids, LFTs

2. Cardiovascular

• ECG annually (monitor QTc, especially for haloperidol/ziprasidone)

3. Other Side Effects

• Anticholinergic: Dry mouth, constipation (review every visit)

• EPSE: Tremor, rigidity, akathisia (check every 6 months)

• Hyperprolactinaemia: Annual history of galactorrhoea, menstrual irregularities, sexual dysfunction

Management of Side Effects

1. Metabolic

• Lifestyle: SNAP (Smoking, Nutrition, Alcohol, Physical activity)

• Pharmacological:

  • Metformin for impaired glucose tolerance or rapid weight gain

  • Statins or ACE inhibitors for dyslipidaemia or hypertension

2. EPSE

• Lower dose or switch to lower-risk agents (e.g., quetiapine, clozapine)

• Acute dystonia/parkinsonism: Benztropine

• Akathisia: Propranolol or lorazepam

3. Hyperprolactinaemia

• Switch to a low-prolactin agent (e.g., aripiprazole) if symptomatic

Key History Questions

• Recent weight gain, dietary/exercise changes

• Sedation, fatigue, or functional difficulties

• Menstrual irregularities, galactorrhoea, sexual dysfunction

• Stiffness, restlessness, tremor (EPSE symptoms)

• History of fainting or palpitations (QTc prolongation)

• Smoking, alcohol use, and medication compliance

Additional Notes

• Regular monitoring reduces cardiovascular risks from long-term antipsychotic use

• Clozapine: Blood monitoring mandatory (weekly for 18 weeks, then less frequent)