First reported 29 Sep 2014•Latest report 14 Jan 2026
Definition
What this concern includes
Includes failures or unresolved safety deficiencies in controls specifically dedicated to clozapine treatment, including evidence and guidance on serious adverse effects, blood and physical-health monitoring, cardiac monitoring, detection of blood cancers or cardiomyopathies, missed-test tracking, care plans, audit, toxicity warnings and communication to patients, families or staff.
Not included
Excludes medication-safety concerns involving medicines other than clozapine unless the report explicitly ties them to the clozapine safety system.
Excludes generic clinical training, communication, record-keeping or monitoring deficiencies that are not specifically dedicated to clozapine treatment.
Excludes prescribing, administration, supply or adherence failures where clozapine-specific safety monitoring or guidance is not the unsafe condition.
Excludes treatment of an established blood cancer, cardiomyopathy or other adverse effect after the clozapine safety-monitoring process has operated adequately.
Excludes general oncology, cardiac-screening or antipsychotic-treatment concerns without a material clozapine connection.
Reports
17
Distinct published reports
Individual concerns
25
A report can raise multiple concerns
Date range
2014–2026
First to latest report issue date
Stated actions
52
Described in published responses
Reports over time
Reports over time
Reports about this concern issued each year.
* 2026 is projected from reports observed to 7 Sep 2026.
Most frequent recipients
Most frequent recipients
Reports about this concern sent to each recipient.
Department of Health and Social Care7
Medicines and Healthcare products Regulatory Agency4
NHS England3
Birmingham and Solihull Mental Health NHS Foundation Trust2
Midlands Partnership University NHS Foundation Trust2
Royal College of Psychiatrists2
Betsi Cadwaladr University LHB1
BNF Publications1
Britannia Pharmaceuticals Limited1
Cardiff & Vale University LHB1
Care Quality Commission1
Croydon University Hospital1
Devon Partnership NHS Trust1
Edgware Community Hospital1
Hampshire and Isle of Wight Healthcare NHS Foundation Trust1
NHS trust8
Ministerial department7
Executive non-departmental public body4
Medicines and medical devices regulator4
Healthcare site2
Local health board2
Professional body2
Health and social care service regulator1
Health professional body1
Independent healthcare provider1
Integrated care board1
Private limited company1
Sub-organisation1
Type not available1
Concerns and responses across reports
Only concerns grouped under this recurring concern are included. Select any concern, action or position to view the source wording.
Staffordshire and Stoke-on-Trent
Concerns raised1
Lack of guidance on steps to take when high serum clozapine levels are returned
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
Actions described in response An action is something a respondent says it has done, is doing, or plans to do in response to the concern raised.3
Action
Write to all Mental Health Chief Pharmacists requesting local clozapine clinics review and update plasma-level monitoring information and support materials.
Stated by NHS EnglandStated completedThe respondent said that this action was complete when they made their response on 10 February 2026.
Action
Maintain a clozapine standard operating procedure covering prescribing, monitoring, administration, supply and assessment of serum levels.
Stated by Midlands Partnership University NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 10 February 2026.
Action
Recirculate the clozapine standard operating procedure to all Integrated Mental Health Team prescribers in Burntwood and Lichfield.
Stated by Midlands Partnership University NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 10 February 2026.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.4
Position
Existing national and local guidance is considered sufficient to support decisions on high clozapine plasma levels.
Stated by NHS EnglandExisting arrangements considered sufficientThe respondent said that existing arrangements were sufficient, so no further action was needed.
Position
Interpretation of clozapine plasma levels is assigned to individual trusts, based on general guidance and local clinical circumstances.
Stated by NHS EnglandRedirects responsibilityThe respondent said that another organisation was responsible for deciding or taking action.
Position
A Trust SOP already provides local guidance on assessing high clozapine serum levels.
Stated by Midlands Partnership University NHS Foundation TrustDisputes the concernThe respondent disagreed with part of the concern or the basis for it.
Position
Guidance cannot be more prescriptive because individual toxicity, clinical response and mental-health risks require clinician-specific decisions.
Stated by Midlands Partnership University NHS Foundation TrustUnable to actThe respondent said that a constraint prevented them from taking the relevant action.
South London
Concerns raised1
Failure to identify the risks of deterioration and death from suspected acute obstruction in patients chronically on Clozapine
This report raised 3 other concerns. They are not shown here because they do not form part of this recurring concern.
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
No linked response statements
No respondent-stated action or position is linked to these concerns in the published data.
London South
Concerns raised1
Lack of clinical staff awareness of Clozapine's potential fatal side effects
This report raised 1 other concern. They are not shown here because they do not form part of this recurring concern.
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
Actions described in response An action is something a respondent says it has done, is doing, or plans to do in response to the concern raised.3
Action
Raised clinician awareness of clozapine side effects by communicating associated risks to mental health chief pharmacists and health communities.
Stated by NHS EnglandStated completedThe respondent said that this action was complete when they made their response on 7 March 2025.
Action
Review clozapine product information and consider whether warnings for healthcare professionals, patients and carers can be clarified.
Stated by Medicines and Healthcare products Regulatory AgencyStated in progressThe respondent said that this action was in progress when they made their response on 7 March 2025.
Action
Engage relevant stakeholders during the clozapine product-information review to ensure regulatory documents meet patients’ and prescribers’ needs.
Stated by Medicines and Healthcare products Regulatory AgencyStated plannedThe respondent said that this action was planned when they made their response on 7 March 2025.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.1
Position
Commenting on clinical decisions in specific cases, including those concerning clozapine, is outside the respondent’s remit.
Stated by Medicines and Healthcare products Regulatory AgencyOutside remitThe respondent said that this matter was outside its role or authority.
Devon, Plymouth and Torbay
Concerns raised2
Failure to routinely detect Clozapine-associated cardiomyopathies
Limited provision of Clozapine side-effect and red-flag information to patients attending GP practices
This report raised 2 other concerns. They are not shown here because they do not form part of this recurring concern.
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
Actions described in response An action is something a respondent says it has done, is doing, or plans to do in response to the concern raised.12
Action
Add questions about recent physical illness, palpitations, chest pain, breathlessness and dizziness to monthly Clozapine clinic appointments.
Stated by Devon Partnership NHS TrustStated plannedThe respondent said that this action was planned when they made their response on 7 February 2025.
Action
Continue seeking expert opinions on screening unsuspected patients for Clozapine-associated cardiomyopathy.
Stated by Devon Partnership NHS TrustStated in progressThe respondent said that this action was in progress when they made their response on 7 February 2025.
Action
Ensure clinicians conducting clozapine monitoring appointments are aware of relevant physical effects and side effects.
Stated by Pembroke Medical GroupStated completedThe respondent said that this action was complete when they made their response on 7 February 2025.
Action
Share discussion outcomes and relevant national policy changes concerning Clozapine cardiac monitoring within local systems.
Stated by NHS Devon Integrated Care BoardStated plannedThe respondent said that this action was planned when they made their response on 7 February 2025.
Action
Implement relevant changes arising from national policy developments within local systems.
Stated by NHS Devon Integrated Care BoardStated plannedThe respondent said that this action was planned when they made their response on 7 February 2025.
Action
Establish specialist Clozapine clinics providing monthly side-effect screening and patient discussions during phlebotomy appointments.
Stated by Devon Partnership NHS TrustStated completedThe respondent said that this action was complete when they made their response on 7 February 2025.
Action
Develop a business case to increase resources for dedicated specialist Clozapine clinics across Devon.
Stated by Devon Partnership NHS TrustStated completedThe respondent said that this action was complete when they made their response on 7 February 2025.
Action
Bring patients receiving Clozapine under Trust care onto dedicated specialist clinics across Devon, excluding Plymouth.
Stated by Devon Partnership NHS TrustStated plannedThe respondent said that this action was planned when they made their response on 7 February 2025.
Action
Review clozapine product information and consider improving its clarity for healthcare professionals, patients, families and carers.
Stated by Medicines and Healthcare products Regulatory AgencyStated in progressThe respondent said that this action was in progress when they made their response on 7 February 2025.
Action
Engage relevant stakeholders during the clozapine product-information review to ensure regulatory documents meet patients’ and prescribers’ needs.
Stated by Medicines and Healthcare products Regulatory AgencyStated plannedThe respondent said that this action was planned when they made their response on 7 February 2025.
Action
Withdraw from the agreement to provide clozapine phlebotomy services.
Stated by Pembroke Medical GroupStated completedThe respondent said that this action was complete when they made their response on 7 February 2025.
Action
Cascade additional funding to support more Clozapine clinics and increase access to specially trained professionals.
Stated by NHS Devon Integrated Care BoardStated plannedThe respondent said that this action was planned when they made their response on 7 February 2025.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.4
Position
Routine echocardiography is not adopted for Clozapine cardiomyopathy screening because evidence does not support it and its cost is excessive.
Stated by Devon Partnership NHS TrustUnable to actThe respondent said that a constraint prevented them from taking the relevant action.
Position
Clinical discussions with prescribers and care delivered by the Trust fall outside the regulator’s remit, so it cannot directly address them.
Stated by Medicines and Healthcare products Regulatory AgencyOutside remitThe respondent said that this matter was outside its role or authority.
Position
Primary care cannot undertake echocardiography for clozapine monitoring because it does not have echocardiography facilities.
Stated by Pembroke Medical GroupUnable to actThe respondent said that a constraint prevented them from taking the relevant action.
Position
Cardiac monitoring changes depend on updates to national clinical guidance, with local implementation following any such changes.
Stated by NHS Devon Integrated Care BoardRedirects responsibilityThe respondent said that another organisation was responsible for deciding or taking action.
Manchester South
Concerns raised1
Potential increased risk of certain blood cancers among patients taking Clozapine
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
Actions described in response An action is something a respondent says it has done, is doing, or plans to do in response to the concern raised.4
Action
Conduct routine pharmacovigilance, including case-report monitoring, literature review, signal assessment, regulatory reporting and periodic safety updates, with continued safety-profile assessment.
Stated by Viatris UK Healthcare LimitedStated completedThe respondent said that this action was complete when they made their response on 31 July 2024.
Action
Complete a signal-validation and assessment exercise on potential associations between clozapine and haematological malignancies, including literature and safety-data analysis.
Stated by Viatris UK Healthcare LimitedStated completedThe respondent said that this action was complete when they made their response on 31 July 2024.
Action
Continue pharmacovigilance activities, including collecting and evaluating safety information and monitoring Zaponex’s safety profile.
Stated by Leyden DeltaStated completedThe respondent said that this action was complete when they made their response on 31 July 2024.
Action
Encourage and carefully review further research into clozapine and acute myeloid leukaemia.
Stated by Leyden DeltaStated plannedThe respondent said that this action was planned when they made their response on 31 July 2024.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.7
Position
MHRA, rather than NICE, should lead surveillance and investigation of clozapine’s safety and haematological malignancy risks.
Stated by National Institute for Health and Care ExcellenceRedirects responsibilityThe respondent said that another organisation was responsible for deciding or taking action.
Position
NIHR, rather than NICE, is responsible for clinical research into clozapine and related safety risks.
Stated by National Institute for Health and Care ExcellenceRedirects responsibilityThe respondent said that another organisation was responsible for deciding or taking action.
Position
Available evidence does not establish that clozapine increases the incidence of haematological malignancies.
Stated by Viatris UK Healthcare LimitedDisputes the concernThe respondent disagreed with part of the concern or the basis for it.
Position
Ongoing pharmacovigilance and routine safety monitoring are considered sufficient, so no additional action is required.
Stated by Viatris UK Healthcare LimitedExisting arrangements considered sufficientThe respondent said that existing arrangements were sufficient, so no further action was needed.
Position
A causal relationship between clozapine and blood cancer has not been established or confirmed by current evidence.
Stated by Britannia Pharmaceuticals Limited and STADA Arzneimittel AGDisputes the concernThe respondent disagreed with part of the concern or the basis for it.
Position
The slightly increased blood-cancer risk associated with clozapine is outweighed by its overall reduction in mortality.
Stated by Britannia Pharmaceuticals Limited and STADA Arzneimittel AGDisputes the concernThe respondent disagreed with part of the concern or the basis for it.
Position
There is no convincing evidence that clozapine causes acute myeloid leukaemia, and pharmacovigilance has identified no causal link.
Stated by Leyden DeltaDisputes the concernThe respondent disagreed with part of the concern or the basis for it.
County Durham and Darlington
Concerns raised2
Failure of clozapine packaging and leaflets to warn that combined use with alcohol may cause death
Lack of guidance on the risk of death from combined clozapine and alcohol use
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
Actions described in response An action is something a respondent says it has done, is doing, or plans to do in response to the concern raised.5
Action
Conduct a further assessment of clozapine product information on drug-drug interactions and consider improvements for healthcare professionals, patients, families and carers.
Stated by Medicines and Healthcare products Regulatory AgencyStated plannedThe respondent said that this action was planned when they made their response on 22 February 2024.
Action
Work with the British National Formulary as the clozapine assessment progresses.
Stated by Medicines and Healthcare products Regulatory AgencyStated plannedThe respondent said that this action was planned when they made their response on 22 February 2024.
Action
Review and revise pharmacodynamic interaction wording on sedative and CNS-depressant risks in BNF messages and tables.
Stated by BNF PublicationsStated plannedThe respondent said that this action was planned when they made their response on 22 February 2024.
Action
Add pharmacodynamic interaction tables to online BNF and BNFC versions.
Stated by BNF PublicationsStated completedThe respondent said that this action was complete when they made their response on 22 February 2024.
Action
Share the coroner’s report with NICE for consideration of its findings in published guidance.
Stated by Department of Health and Social CareStated completedThe respondent said that this action was complete when they made their response on 22 February 2024.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.2
Position
MHRA is responsible for assessing and potentially improving clozapine product information about drug interactions and associated safety risks.
Stated by Department of Health and Social CareRedirects responsibilityThe respondent said that another organisation was responsible for deciding or taking action.
Position
NICE is responsible for considering whether the report’s findings should affect published guidance on clozapine and alcohol risks.
Stated by Department of Health and Social CareRedirects responsibilityThe respondent said that another organisation was responsible for deciding or taking action.
Hampshire, Portsmouth and Southampton
Concerns raised1
Failure of clozapine services to provide annual physical-health blood testing
This report raised 2 other concerns. They are not shown here because they do not form part of this recurring concern.
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
Actions described in response An action is something a respondent says it has done, is doing, or plans to do in response to the concern raised.4
Action
Operationalise blood sampling in Mid and North Hampshire Clozapine clinics using equipment, blood transport arrangements and a staff rota.
Stated by Hampshire and Isle of Wight Healthcare NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 26 September 2023.
Action
Develop systems to identify required blood tests, record completed samples, optimise patient records and track results for Mid and North Hampshire Clozapine clinics.
Stated by Hampshire and Isle of Wight Healthcare NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 26 September 2023.
Action
Review variation in service provision across Clozapine clinics and use the findings to inform improvement.
Stated by Hampshire and Isle of Wight Healthcare NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 26 September 2023.
Action
Establish consistent principles across Clozapine clinics for annual health-check capacity, preferred onsite blood sampling and robust results-review systems.
Stated by Hampshire and Isle of Wight Healthcare NHS Foundation TrustStated plannedThe respondent said that this action was planned when they made their response on 26 September 2023.
Birmingham and Solihull
Concerns raised2
Lack of understanding of clozapine level monitoring, interpretation and response
Failure to highlight high clozapine results in routinely used clinical notes
This report raised 6 other concerns. They are not shown here because they do not form part of this recurring concern.
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
Actions described in response An action is something a respondent says it has done, is doing, or plans to do in response to the concern raised.8
Stated by Medicines and Healthcare products Regulatory AgencyStated completedThe respondent said that this action was complete when they made their response on 18 July 2023.
Action
Write to marketing authorisation holders to investigate further thresholds for clozapine toxicity.
Stated by Medicines and Healthcare products Regulatory AgencyStated plannedThe respondent said that this action was planned when they made their response on 18 July 2023.
Action
Deliver and record a clozapine training webinar for clinical staff, with intranet access for those unable to attend.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated plannedThe respondent said that this action was planned when they made their response on 18 July 2023.
Action
Develop clozapine e-learning modules and take them to the Learning and Development team for approval.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 18 July 2023.
Action
Establish a specialist Pharmacy Clozapine Team to support assay follow-up, staff training and clozapine prescribing practice.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 18 July 2023.
Action
Put support processes in place to guide clinicians who are new to the Trust when clozapine prescribing advice is needed.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated plannedThe respondent said that this action was planned when they made their response on 18 July 2023.
Action
Email prescribers about documenting care decisions and clinical review following out-of-range clozapine results.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 18 July 2023.
Action
Implement an urgent clozapine learning session and provide future training and development to refresh staff knowledge.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 18 July 2023.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.1
Position
Existing ICE access, abnormal-result indicators and pharmacy reporting provide the strongest safeguards for recording and responding to high clozapine levels.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustExisting arrangements considered sufficientThe respondent said that existing arrangements were sufficient, so no further action was needed.
Birmingham and Solihull
Concerns raised4
Lack of clear national guidance on clozapine monitoring frequency and blood test type
Lack of understanding of the importance and frequency of clozapine level monitoring
Failure to act on high clozapine blood test results through repeat testing and dose adjustment
Lack of understanding of clozapine monitoring, blood test selection and drug effects
This report raised 2 other concerns. They are not shown here because they do not form part of this recurring concern.
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
Actions described in response An action is something a respondent says it has done, is doing, or plans to do in response to the concern raised.9
Action
Deliver clozapine education for junior doctors through the postgraduate medical education programme, using learning from the regulation 28 report.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 26 October 2020.
Action
Provide additional clozapine training to pharmacists to promote consistent advice and rapid responses.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 26 October 2020.
Action
Draft and send a clozapine safety alert to clinicians to support immediate action where necessary.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 26 October 2020.
Action
Audit all patients prescribed clozapine on the identified doctor’s caseload for unconsidered anomalous results.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 26 October 2020.
Action
Issue a practice alert to doctors reminding them to review anomalous clozapine results.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 26 October 2020.
Action
Strengthen multidisciplinary meeting focus on physical health and include clozapine in quality-improvement checks of testing and abnormal-result actions.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 26 October 2020.
Action
Send pharmacy reports of clozapine results above 600 to the Clozapine Lead for direct escalation to the Consultant and Divisional Pharmacist.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 26 October 2020.
Action
Review and update the Trust clozapine guidelines following the investigation into Mr Allen’s death.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 26 October 2020.
Action
Disseminate the approved updated clozapine guidance across the Trust as a staff reminder.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStated plannedThe respondent said that this action was planned when they made their response on 26 October 2020.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.2
Position
Routine therapeutic drug monitoring of clozapine blood levels is not required; authorised product information specifies monitoring requirements and toxicity-related exceptions.
Stated by Department of Health and Social CareExisting arrangements considered sufficientThe respondent said that existing arrangements were sufficient, so no further action was needed.
Position
NICE guideline 178 does not require updating because clozapine toxicity risks are detailed in the BNF and authorised product information.
Stated by Department of Health and Social CareExisting arrangements considered sufficientThe respondent said that existing arrangements were sufficient, so no further action was needed.
Manchester South
Concerns raised2
Lack of clear care plans for monitoring Clozapine side-effects and directing staff response to suspected serious complications
Failure to formally review care plans for patients prescribed Clozapine
This report raised 4 other concerns. They are not shown here because they do not form part of this recurring concern.
Responses linked to these concerns
Each statement is shown once, even when linked to more than one concern.
Actions described in response An action is something a respondent says it has done, is doing, or plans to do in response to the concern raised.2
Action
Issue Clozapine guidelines and a care-plan template covering medication side effects and their management.
Stated by Priory GroupStated completedThe respondent said that this action was complete when they made their response on 26 February 2020.
Action
Complete the 2020 formal audit of patient care plans and analyse its results.
Stated by Priory GroupStated completedThe respondent said that this action was complete when they made their response on 26 February 2020.
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Includes failures or unresolved safety deficiencies in controls specifically dedicated to clozapine treatment, including evidence and guidance on serious adverse effects, blood and physical-health monitoring, cardiac monitoring, detection of blood cancers or cardiomyopathies, missed-test tracking, care plans, audit, toxicity warnings and communication to patients, families or staff.
