Clozaril Reviews: Unsurpassed Benefits but Not Without Risks


  • Clozaril is the most effective antipsychotic for treatment-resistant schizophrenia. Up to 60% of patients show significant improvement.
  • Superior to other antipsychotics for both positive and negative symptoms, with benefits often maintained long-term.
  • Also effective for some patients with schizoaffective disorder and severe bipolar disorder unresponsive to lithium or valproate.
  • A last-line treatment due to risks, but indispensable for certain patient groups based on proven superiority over other options.

Safety and tolerability:

  • The main safety concern is agranulocytosis (1% incidence), requiring weekly blood monitoring. Other risks include seizures, myocarditis, and metabolic effects.
  • Sedation, dizziness, and sialorrhea are common but often temporary. Weight gain and nausea also frequently reported.
  • Extrapyramidal side effects and tardive dyskinesia are less likely than with typical antipsychotics due to weaker D2 and stronger 5-HT2A antagonism.
  • Safety risks can be mitigated through slow titration, dosage adjustments, and close monitoring. However, some effects may remain intolerable for certain patients despite optimal management.


  • Initiated at a low dose with gradual upward titration based on response and tolerability. The usual dosage range is 200 to 800 mg/day.
  • Requires a washout period of at least 2 weeks when switching from another antipsychotic. Hospitalization may be needed for initial titration and monitoring.
  • Daily dosage should be divided for sedation and may need to be adjusted with changes in smoking status due to effects on clozapine metabolism.
  • Rigorous tests and monitoring are mandatory to meet safety standards, but also help individualize treatment.
  • Lower doses may suit some elderly or medically compromised patients. Plasma level monitoring helps guide appropriate dosage adjustments in these groups.

Place in therapy:

  • Reserved only for treatment-resistant schizophrenia due to superior efficacy for this population alongside risks and monitoring demands. Not suitable or cost-effective for wider use.
  • An option for schizoaffective disorder or bipolar disorder only when severe symptoms persist after adequate trials of safer alternatives have failed.
  • A last-line treatment but life-changing for otherwise non-responsive groups. Benefits must outweigh risks for any patient to warrant continuation long-term.
  • Limited by safety risks, monitoring burden, and cost. Ongoing research aims to develop comparably effective antipsychotics with improved safety and tolerability to expand access.

In summary, while characterized by a myriad of risks and downsides, Clozaril offers unparalleled benefits for certain severely ill patients with limited alternative treatment options. When properly monitored and managed, efficacy and safety can be balanced to gain optimal outcomes relative to the severity of underlying illness. For some, the rewards of an otherwise elusive clinical response far outweigh the practical challenges of accessing and remaining on this complex but indispensable treatment.

There are various forms of drugs available, such as tablets or liquids, and each may have a separate patient information leaflet (PIL) for different doses. It is important to refer to the PIL for the specific form and dose of the drug that you have been prescribed.

You can search for further information and PILs on websites such as: