First reported 25 Jun 2014•Latest report 14 Jan 2026
Definition
What this concern includes
Includes failures of controls specifically dedicated to monitoring blood levels associated with a prescribed medicine, including guidance on testing thresholds or timing, arrangements for obtaining tests, interpretation of results and review of prescribing or monitoring practice. Includes the anchor's tinzaparin prescribing and blood-level monitoring concern and comparable failures concerning fluoxetine or clozapine levels.
Not included
Excludes routine blood tests or biochemical monitoring where the assertion is not specifically about a medication-associated blood level.
Excludes generic medication prescribing, administration, reconciliation, long-term review or medication-risk recognition failures when medication-specific blood-level monitoring is not the unsafe condition.
Excludes failures concerning a clinical test performed for diagnosis or general disease monitoring rather than to monitor a medicine's level or medication-related toxicity.
Excludes deficiencies limited to treatment response or clinical action after a medication level was reliably obtained, unless the monitoring process itself was also deficient.
Reports
16
Distinct published reports
Individual concerns
22
A report can raise multiple concerns
Date range
2014–2026
First to latest report issue date
Stated actions
39
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 Care5
NHS England3
Birmingham and Solihull Mental Health NHS Foundation Trust2
BNF Publications2
Midlands Partnership University NHS Foundation Trust2
Barnsley Hospital NHS Foundation Trust1
British Association Of Dermatologists1
BTCM Limited1
Cardiff & Vale University LHB1
CareFlow Medicines Management Limited1
Cwm Taf Morgannwg University Local Health Board1
Egton Medical Information Systems Limited1
Essex Partnership University NHS Foundation Trust1
Glangwili General Hospital1
Medicines and Healthcare products Regulatory Agency1
NHS trust9
Ministerial department5
Executive non-departmental public body4
Healthcare site2
Local health board2
Sub-organisation2
Company1
Company limited by guarantee1
Devolved government1
Integrated care board1
Medicines and medical devices regulator1
Multi-service care provider1
Private limited company1
Professional body1
Registered charity1
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.
Essex
Concerns raised1
Failure to escalate and act on markedly subtherapeutic clozapine levels
This report raised 7 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.1
Action
Take forward MDT learning on documenting and escalating inconsistencies between clozapine assays, adherence reports and clinical stability.
Stated by Essex Partnership University NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 14 August 2025.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.2
Position
The clozapine assay showed low plasma levels, not sub-therapeutic prescribing, because the prescribed dose remained unchanged.
Stated by Essex Partnership University NHS Foundation TrustDisputes the concernThe respondent disagreed with part of the concern or the basis for it.
Position
Clinical assessment and the already scheduled psychiatric review were considered sufficient; no earlier appointment was indicated without evidence of deterioration.
Stated by Essex Partnership University NHS Foundation TrustExisting arrangements considered sufficientThe respondent said that existing arrangements were sufficient, so no further action was needed.
Cornwall and Isles of Scilly
Concerns raised1
Lack of guidance specifying when to test fluoxetine blood levels after palpitations
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.1
Action
Review evidence and expert advice on monitoring fluoxetine blood levels and relevant toxicity risks.
Stated by Medicines and Healthcare products Regulatory AgencyStated completedThe respondent said that this action was complete when they made their response on 8 September 2023.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.3
Position
The MHRA is best placed to address fluoxetine monitoring requirements because these are covered by the MHRA-agreed product characteristics.
Stated by National Institute for Health and Care ExcellenceRedirects responsibilityThe respondent said that another organisation was responsible for deciding or taking action.
Position
Routine fluoxetine blood-level monitoring is not recommended because evidence is insufficiently robust and therapeutic plasma levels lack supporting data.
Stated by Medicines and Healthcare products Regulatory AgencyNo action considered necessaryThe respondent said that no further action was needed.
Position
Specific recommendations for fluoxetine blood testing are a matter for clinical guidelines because testing depends on individual patient circumstances and clinical judgment.
Stated by Medicines and Healthcare products Regulatory AgencyRedirects responsibilityThe respondent said that another organisation was responsible for deciding or taking action.
Birmingham and Solihull
Concerns raised3
Lack of understanding of clozapine level monitoring, interpretation and response
Failure to highlight high clozapine results in routinely used clinical notes
Failure to monitor clozapine and norclozapine levels
This report raised 5 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.11
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.
Action
Continue reviewing clozapine toxicity monitoring, including Yellow Card cases.
Stated by Medicines and Healthcare products Regulatory AgencyStated in progressThe respondent said that this action was in progress when they made their response on 18 July 2023.
Action
Review governance processes for clozapine management using a safety summit approach.
Stated by Birmingham and Solihull Mental Health NHS Foundation TrustStatus unclearThe respondent did not make the status of this action clear when they made their response on 18 July 2023.
Action
Prioritise pharmacy review of clozapine assay levels and communication of results to consultants as an interim mitigation.
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.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.2
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.
Position
Clozapine plasma-level monitoring is optional, individualised, and lacks defined safe upper limits; the product information does not mandate it.
Stated by Medicines and Healthcare products Regulatory AgencyDisputes the concernThe respondent disagreed with part of the concern or the basis for it.
Stoke-on-Trent and North Staffordshire
Concerns raised1
Failure to routinely and regularly test transplant patients’ magnesium levels
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
Issue a reminder alert on magnesium monitoring for patients taking proton pump inhibitors who are at risk of hypomagnesemia.
Stated by NHS EnglandStated plannedThe respondent said that this action was planned when they made their response on 24 March 2021.
Action
Undertake an expert clinical review recommending magnesium monitoring for immunosuppressed patients and reviewing proton pump inhibitor and H2 antagonist prescribing with calcineurin inhibitors.
Stated by NHS EnglandStated plannedThe respondent said that this action was planned when they made their response on 24 March 2021.
Action
Disseminate updated guidance to clinical teams caring for kidney transplant recipients through the Renal Networks.
Stated by NHS EnglandStated plannedThe respondent said that this action was planned when they made their response on 24 March 2021.
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
Insufficient education of Mental Health practitioners on clozapine monitoring and level adjustment
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.7
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.
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 West
Concerns raised2
Conflicting guidance on timing of Vitamin D and Calcium blood level monitoring
Failure to provide community GPs with instructions on blood level monitoring during high-dose Vitamin D treatment
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.
No linked response statements
No respondent-stated action or position is linked to these concerns in the published data.
Cumbria
Concerns raised1
Failure to consider and recommend blood-level monitoring for powerful antipsychotics in older, frail patients receiving long-term high-dose treatment
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.1
Action
Review measures for monitoring patients receiving prolonged high-dose antipsychotic treatment.
Stated by Cumbria, Northumberland, Tyne and Wear NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 21 September 2020.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.1
Position
Routine plasma-level monitoring is not recommended for quetiapine or amisulpride because antipsychotic toxicity is assessed clinically.
Stated by Cumbria, Northumberland, Tyne and Wear NHS Foundation TrustDisputes the concernThe respondent disagreed with part of the concern or the basis for it.
South Wales Central
Concerns raised1
Failure to account for smoking cessation when managing clozapine levels
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.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.2
Position
Existing medicines reconciliation, pharmacist support, NICE monitoring and promoted polypharmacy reviews address medication interaction and prescribing risks.
Stated by Cardiff & Vale University LHBExisting arrangements considered sufficientThe respondent said that existing arrangements were sufficient, so no further action was needed.
Position
Mandated Clozapine monitoring, ZTAS reporting and primary-care record checks are considered sufficient for shared prescribing and information exchange.
Stated by Cardiff & Vale University LHBExisting arrangements considered sufficientThe respondent said that existing arrangements were sufficient, so no further action was needed.
Manchester North
Concerns raised1
Failure to establish shared care arrangements or identify an organisation for blood sampling for drug monitoring
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.10
Action
Modify patient letters to explain blood-test arrangements clearly and provide an SRFT contact for monitoring difficulties.
Stated by Northern Care Alliance NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 2 June 2019.
Action
Ask GPs before ESA treatment whether they can monitor bloods, record responses electronically, agree monitoring plans, and follow up non-responses.
Stated by Northern Care Alliance NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 2 June 2019.
Action
Assume responsibility for taking bloods until the GP responds, ensuring clinically necessary ESA treatment can begin.
Stated by Northern Care Alliance NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 2 June 2019.
Action
Develop and implement a standard operating policy covering ESA blood-monitoring arrangements, outstanding responses, and negative responses.
Stated by Northern Care Alliance NHS Foundation TrustStated completedThe respondent said that this action was complete when they made their response on 2 June 2019.
Action
Write to existing ESA patients to identify difficulties accessing monitoring and manage identified difficulties under the agreed policy.
Stated by Northern Care Alliance NHS Foundation TrustStated plannedThe respondent said that this action was planned when they made their response on 2 June 2019.
Action
Explore a Greater Manchester commissioned shared-care protocol for ESA monitoring through CCGs and the Medicines Management Group.
Stated by Northern Care Alliance NHS Foundation TrustStated in progressThe respondent said that this action was in progress when they made their response on 2 June 2019.
Action
Establish an operating procedure requiring direct GP communication and a provider response before confirming monitoring-dependent treatment plans.
Stated by NHS Oldham CCGStated plannedThe respondent said that this action was planned when they made their response on 2 June 2019.
Action
Describe the shared-care model in a business case for consideration by the Greater Manchester Medicines Management Group and local commissioners.
Stated by NHS Oldham CCGStated plannedThe respondent said that this action was planned when they made their response on 2 June 2019.
Action
Identify patients receiving or potentially requiring shared-care ESA pathways and write to GP practices to promote robust monitoring.
Stated by NHS Oldham CCGStated completedThe respondent said that this action was complete when they made their response on 2 June 2019.
Action
Notify the CCG that the Practice was asked to monitor a red-status medication and report the associated significant event.
Stated by St Chads Medical PracticeStated completedThe respondent said that this action was complete when they made their response on 2 June 2019.
Respondent positions A position is what a respondent says about the concern when they do not describe a specific action.2
Position
The community nursing service was commissioned to provide phlebotomy only for housebound patients, and this patient was not housebound.
Stated by Pennine Care NHS Foundation TrustOutside remitThe respondent said that this matter was outside its role or authority.
Position
The Practice should not accept responsibility for monitoring EPO; the CCG will liaise directly with the Trust and medicines management.
Stated by St Chads Medical PracticeRedirects responsibilityThe respondent said that another organisation was responsible for deciding or taking action.
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Includes failures of controls specifically dedicated to monitoring blood levels associated with a prescribed medicine, including guidance on testing thresholds or timing, arrangements for obtaining tests, interpretation of results and review of prescribing or monitoring practice. Includes the anchor's tinzaparin prescribing and blood-level monitoring concern and comparable failures concerning fluoxetine or clozapine levels.
