National Patient Safety Alert: Class 1 Medicines Recall Notification: Mexiletine hydrochloride 50mg, 100mg & 200 mg Hard Capsules (Clinigen Healthcare Ltd)

National Patient Safety Alert: Class 1 Medicines Recall Notification: Recall of Mexiletine hydrochloride 50mg, 100mg and 200 mg Hard Capsules, Clinigen Healthcare Ltd, due to a potential for underdosing and/or overdosing

National Patient Safety Alert Reference Number: NatPSA/2022/007/MHRA

Date issued: 4th August 2022

Clinigen Healthcare Ltd is initiating a recall of three batches of Mexiletine hydrochloride hard capsules due to a potential risk of underdose or overdose, which could have consequences for the safety of patients.

Mexiletine hydrochloride 50mg Hard Capsules – PL 31644/0027

Batch Number Expiry Date Pack Size First Distributed
2111216 02/2024* 84 capsules 10/02/2022

*Per correction by Clinigen Healthcare Ltd, an update was made to correct the expiry date to reflect 02/2024

Mexiletine hydrochloride 100mg Hard Capsules – PL 31644/0028

Batch Number Expiry Date Pack Size First Distributed
2111217 04/2024 84 capsules 10/02/2022

Mexiletine hydrochloride 200mg Hard Capsules – PL 31644/0029

Batch Number Expiry Date Pack Size First Distributed
2111218 04/2024 100 capsules 10/02/2022

Active Pharmaceutical Ingredients: mexiletine hydrochloride

Explanation of identified safety issue

Clinigen Healthcare Ltd is initiating a recall of three batches of Mexiletine hydrochloride hard capsules due to a potential risk of underdose or overdose, which could have consequences for the safety of patients.

Stability testing identified that some individual capsules on the market may fall outside the individual fill-weight range. This means that there is the potential for some capsules to contain too little active ingredient and for some to contain too much active ingredient. This could result in potential underdosing and overdosing.

Clinigen Healthcare Ltd has confirmed that no alternative batches of Mexiletine hydrochloride 50mg, 100mg or 200mg hard capsules will be available until later in the year, therefore the recall of these batches from patients should only be considered where patients have access to appropriate alternative products. See below for more information on resupplying patients with alternative products.

Patients should be advised not to stop any treatments without consulting their relevant healthcare professional. The risks of suddenly stopping medication for ventricular arrhythmias is higher than the potential risk presented by too much or too little of the active ingredient in the capsule.

Actions required – to complete by 12 August 2022

The action to recall should be coordinated by the Chief Pharmacist/Superintendent Pharmacist/Responsible Pharmacist and Dispensing GPs in the first instance.

  1. Stop supplying the impacted batch immediately. Quarantine all remaining stock and return it to your supplier/MAH using your supplier’s approved process.
  2. Identify and immediately contact all patients who have been dispensed the impacted batch and ask them to confirm if they have remaining stock within their possession. If batch traceability information is not available, all patients dispensed this product since 10 February 2022 should be contacted.
  3. If the pharmacist identifies any patients with an impacted batch, they should, in the first instance, contact the patient’s GP and discuss alternative mexiletine treatment of the patient. As this is a specialist use product and patients may require monitoring, other clinicians and healthcare professionals may need to be involved.
  4. Discuss the risk of cardiac arrhythmias with patients and advise them to seek urgent medical attention if they experience any new or worsening of symptoms of an arrhythmia including palpitations, angina pain, chest discomfort, dizziness and loss of consciousness.

Healthcare professionals may also consider the use of unlicensed medicines where appropriate. See the MHRA recall notice for more information.

Advice for healthcare professionals

Patients should be advised not to stop any treatments without consulting their relevant healthcare professional. The risks of suddenly stopping medication for ventricular arrhythmias is higher than the potential risk presented by continuing to take capsules containing too much or too little of the active ingredient. This product should only be recalled from patients when it has been confirmed that the patient has access to an alternative mexiletine product.

Healthcare professionals should be aware of the clinical considerations related to the potential risk of either under- or overdosing. See the MHRA recall notice for more information.

Advice for healthcare professionals on recall and resupply

If the pharmacist identifies any patients with an impacted batch, they should, in the first instance, contact the patient’s GP and discuss alternative mexiletine treatment for the patient. As this is a specialist use product and patients may require monitoring, other clinicians and healthcare professionals may need to be involved.

Healthcare professionals should be aware that other licensed preparations for mexiletine are available. Whilst licensed mexiletine products marketed by Clinigen Healthcare Ltd are out of stock, the only other licensed mexiletine product available is Namuscla 167mg (equivalent to 200mg mexiletine hydrochloride) hard capsules, Summary of Product Characteristics (SmPC): https://www.medicines.org.uk/emc/product/9838/smpc#gref

  • Namuscla 167mg hard capsules: Namuscla is indicated for the symptomatic treatment of myotonia in adult patients with non-dystrophic myotonic disorders and is not indicated for treatment of life-threatening ventricular arrhythmias and supply would be considered “off-label” use.
  • Although the MHRA does not recommend “off label” (outside of the licensed indications) use of products, if alternative UK licensed products can meet the patients clinical need, even “off-label”, they should be used instead of an unlicensed product. Licensed products available in the UK have been assessed for quality, safety, and efficacy. It should be understood that the prescribing healthcare professional’s responsibility and potential liability are increased when prescribing off-label.

Healthcare professionals may consider that an unlicensed product (special) should be used as an alternative mexiletine product for patients requiring maintenance doses and any dose titrations in the absence of alternative licensed products.

See Department of Health and Social Care Guidance on ordering and prescribing unlicensed imports:

  • Any decision to prescribe an unlicensed medicine must consider the relevant guidance and NHS Trust or local governance procedures. Please see the links below for further information:
  • When prescribing a product that is not licensed in the UK due to a supply issue with the licensed alternative, prescribers must indicate on the FP10 prescription that an unlicensed product is required. This can be done in one of the following two ways:
    • Electronic prescriptions – if the required unlicensed product is shown on electronic prescribing systems, GPs should select:
      • Mexiletine 50mg capsules (imported)
      • Mexiletine 100mg capsules (imported)
    • Paper prescriptions – where the unlicensed product is not shown on electronic prescribing systems, GPs should use a paper prescription and annotate with the following wording: “special order”.

Patients should be advised to report any side effects to their healthcare professional and via the MHRA’s Yellow Card scheme.

Further information

For more information or stock and resupply queries, please contact Quantum Pharmaceutical +44 (0) 1207 279 400 or email enquiries@quantumpharma.co.uk.

For medical information queries, please contact Clinigen Medical Information on +44 (0) 1932 824 026 or email medicalinformation@clinigengroup.com.

For all other enquires place contact Clinigen Healthcare Ltd on +44 (0) 1283 494 340 or email medicineaccess@clinigengroup.com.

View full notice here.


Advice for patients

Patients should not stop taking mexiletine without consulting your relevant healthcare professional. The risks of suddenly stopping medication for ventricular arrhythmias is higher than the potential risk presented by taking capsules containing too much or too little mexiletine.

See further information in the supplementary letter explaining any potential observations relating to underdosing and/or overdosing. See more information in the Download Document section of the MHRA National Patient Safety Alert webpage.

If you feel unwell or experience any of the symptoms mentioned relating to either underdose or overdose, please contact your doctor immediately or visit the nearest accident and emergency centre

Download documents

National Patient Safety Alert Recall of Mexiletine hydrochloride 50mg, 100mg and 200mg Hard Capsules, Batch 2111218, Clinigen Healthcare Ltd due to a potential for under and/or overdosing

Class 1 Medicines Recall Notification, Clinigen Healthcare Ltd, Mexiletine hydrochloride 50mg, 100mg and 200mg Hard Capsules

Supplementary information for HCPs/Patients: Clinigen Healthcare Ltd, Mexiletine hydrochloride 50mg, 100mg and 200mg Hard Capsules

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