Clozapine counselling

• Clozapine is an atypical antipsychotic mediation used for treatment-resistant schizophrenia
• How to take:

  • Comes in tablet or liquid form, not available as injection
  • Started as a low dose and titrated up over a period of several weeks
• Common side effects:

  • Sedation - dose usually taken at night
  • Constipation - bowel monitoring, high fibre diet and stimulant laxatives
  • Tachycardia - persistent tachycardia could represent a cardiac problem, otherwise use beta-blockers
  • Weight gain - dietary advice, metformin
  • Hypersalivation - often improves, hyoscine can be used
  • Blood pressure - hypotension or hypertension
  • Hyperglycaemia - may require oral hypoglycaemics or insulin
• Rare but serious side effects:

  • Neutropenia - small drop in WCC
  • Agranulocytosis - significant drop in WCC - seek urgent medical advice if develop symptoms of infection
  • Lowers seizure threshold
  • Cardiac complications - myocarditis and cardiomyopathy
  • Constipation can lead to ileus and bowel obstruction
• Baseline investigations usually include:

  • ECG
  • Blood pressure and pulse
  • Calculation of body mass index (BMI)
  • Laboratory investigations: FBC, U&Es, LFTs, prolactin, HbA1c and lipids. For clozapine, a baseline troponin is also requested.
• Monitoring:

  • During first 18 weeks - weekly FBC
  • After 18 weeks - fortnightly FBC
  • After 1 year - monthly FBC
  • All patients taking clozapine will be registered with the service that manufactures their treatment and medication will only be dispensed if blood tests are within acceptable limits
  • Plasma levels of clozapine are monitored in some circumstances - poor compliance, high doses required and when smoking status changes
  • Levels can rise significantly with the reduction and cessation of cigarette smoking