Workshop 11 - Antipsychotics in Practice

Question 1

Describe the main differences between 1st and 2nd Generation Antipsychotics and explain why these occur?

Answer 1

1st generation block the D2 receptor, whereas 2nd generation block the receptor but have rapid dissociation from the receptor hence there is no EPS.

Diffirences in side effects

Question 2

Describe the main side effects associated with 2nd Generation Antipsychotics (SGAS) and explain why these occur?

Answer 2

Immediate side effects:
- Seratonin receptors cause nasuea
- Muscaranic receptors: slow down transit in the body so causes constipation, blurred vision, dry mouth

Long term side effects:
- Metabolic syndrome: weight gain which can cause diabetes

Question 3

What is ‘metabolic syndrome’- explain how it occurs and describe how is it managed / monitored?

Answer 3

Metabolic syndrome is the medical term for a combination of diabetes, high blood pressure (hypertension) and obesity.

Occurs due to insulin resistance,

Monitoring:
- BMI initially then every 3 months
- Waist circumferance
- Hba1c
- Blood pressure
- HDL / LDL proportion

Management:
- Lifestyle advice: lose weight, losing weight
exercising regularly, eating a healthy, balanced diet to keep your blood pressure, cholesterol and blood sugar levels under control
stopping smoking
cutting down on alcohol.

Question 4

Describe the clinical situation(s) where more than one antipsychotic may be used (prescribed) at the same time in the same individual. Are there any patient safety issues associated with this combination?

Answer 4

• Already on a regular antipsychotic but they get acutely disturbed so require an additional drug
• Augmentation for treatment resistanance - one drug isnt having much of an effect so requires an additional drug
• Switching/ tapering: if stopping one to try another
• Poor response to standard treatment

Question 5

What is High Dose Antipsychotic Therapy (HDAT) and how is it managed in routine clinical practice?

Answer 5

A total daily dose that exceeds the dose stated in the BNF. Risk of cardiotoxic side effects.

If dose excess 100% then it is a high dose, and requires monitoring

Question 6

Describe the dispensing arrangements for clozapine and explain why they exist.

Answer 6

• Careful monitoring is required since it is neutrophenic, so requires blood tests to measure neutrophil count
• Dispensed weekly due to weekly blood tests required
• Patient and pharmacist need to be registered in the clozapine blood service
• If patient gets a red blood result, treatment should be discontinued. Get another blood test.
• Start at 25mg daily, gradually titrate up to 900mg.
• If theres a break of >48 hours then dose must be re titrated from 25mg