UK regulator flags domperidone safety risk: Canadian patients and clinicians should watch for Health Canada update

This article is for informational purposes only and is not medical advice. Consult your Canadian healthcare provider about your situation.

On July 21, 2026, the UK's Medicines and Healthcare products Regulatory Agency (MHRA) formally contraindicated domperidone (sold in Canada under the brand name Motilium and in generic form) in any patient with confirmed or suspected phaeochromocytoma, a rare adrenal gland tumour, after a European pharmacovigilance review identified four case reports linking the drug to severe hypertensive episodes. Health Canada has not yet issued a matching safety communication, but the European signal is strong enough that Canadian clinicians and patients with a known or suspected adrenal tumour should not wait for a domestic update before acting.

For Canadians, domperidone is a familiar drug with a profile unlike its situation in the United States. The US Food and Drug Administration (FDA) has never approved domperidone; Health Canada has approved it as a prescription antiemetic for adults and adolescents 12 years and older weighing at least 35 kg. It is also widely used off-label in Canada to stimulate milk production in breastfeeding parents, a use the MHRA update does not address but that Canadian prescribers should keep in mind when reviewing their patient lists. Provincial drug plans vary: domperidone is listed on the Ontario Drug Benefit (ODB) formulary, the Quebec RAMQ formulary, and most provincial formularies as a general benefit, though coverage conditions differ by province.

What this means in Canada

Health Canada has not yet issued guidance mirroring the MHRA's July 2026 update. The Society of Obstetricians and Gynaecologists of Canada (SOGC) has not issued a position statement on this specific contraindication. The Canadian product monograph for domperidone already lists phaeochromocytoma as a contraindication in some versions, reflecting earlier European regulatory work, but the MHRA's July 2026 update formalises and strengthens that language based on new case data. Canadian prescribers should check the current Health Canada-approved product monograph for the specific domperidone product they are prescribing, as monograph language can differ between brand and generic versions.

Patients in Canada who are taking domperidone for nausea, vomiting, or off-label lactation support and who have a history of adrenal tumours, unexplained episodic hypertension, or symptoms such as persistent headache, sweating, and palpitations should contact their prescriber promptly. The MHRA's update also notes that domperidone can unmask a previously undiagnosed phaeochromocytoma: a patient who develops a sudden severe hypertensive episode while on domperidone should be investigated for the tumour, not simply taken off the drug and discharged.

For patients receiving palliative care, the MHRA advises an individual benefit-risk discussion with the patient rather than automatic discontinuation. Canadian palliative care teams should apply the same reasoning.

What changed and why it matters

Phaeochromocytoma is rare. A 2025 systematic review and meta-analysis published in the Journal of Endocrinological Investigation put global prevalence at approximately 19.8 per million people. The absolute number of Canadian patients at risk from this interaction is small. But the severity of the harm, sudden, potentially life-threatening hypertensive crises, justifies a precautionary approach even on a thin evidence base.

The European review that triggered the MHRA update examined four case reports. That is a small number, and the MHRA itself notes it has received zero UK Yellow Card reports of this specific interaction. The signal came through the European Medicines Agency's pharmacovigilance network, not from a large controlled trial. The UK's Pharmacovigilance Expert Advisory Committee reviewed the data and agreed the contraindication was warranted given the severity of the potential outcome and the availability of alternative antiemetics.

Domperidone works as a dopamine antagonist. Phaeochromocytomas secrete catecholamines, and dopamine antagonism can trigger a surge in catecholamine release from the tumour, producing a hypertensive crisis. The mechanism is biologically plausible, which gave regulators additional confidence despite the small case count.

The MHRA also reiterated existing restrictions that Canadian prescribers should already be following: domperidone should be used at the lowest effective dose, for no longer than one week in most cases, and is contraindicated alongside drugs that prolong the QT interval or potent CYP3A4 inhibitors.

What Canadian patients should know

If you are taking domperidone and you have been diagnosed with a phaeochromocytoma or a suspected adrenal tumour, stop the medication and contact your prescriber or pharmacist today. Do not wait for a Health Canada update.

If you are taking domperidone for nausea or vomiting and you have no adrenal tumour history, the MHRA update does not change your risk profile in a meaningful way. Continue as prescribed and raise any concerns at your next appointment.

If you are taking domperidone off-label to support breastfeeding, the phaeochromocytoma contraindication applies to you equally. If you have any history of unexplained high blood pressure episodes, sweating attacks, or headaches, mention this to your prescriber before continuing.

Symptoms of a hypertensive crisis that warrant immediate emergency care include a sudden severe headache, blurred vision, chest pain, and shortness of breath. In Canada, call 911 or go to your nearest emergency department.

Canadian telehealth platforms including Maple, Telus Health, and Felix can facilitate prescription reviews, but a sudden hypertensive episode is not a telehealth situation. Go to an emergency department.

Adverse drug reactions in Canada should be reported to Health Canada's Canada Vigilance Program online at canada.ca/en/health-canada/services/drugs-health-products/medeffect-canada.html or by calling 1-866-234-2345.

Limitations and open questions

The evidence base is four case reports from a European review. No randomised trial data exist, and no Canadian case reports have been published. The MHRA's own pharmacovigilance database contains zero reports of this interaction. The contraindication is precautionary, grounded in biological plausibility and the severity of the potential harm rather than a large body of clinical evidence.

Health Canada has not confirmed whether it will issue a parallel safety communication or update Canadian product monographs. The SOGC has not commented. It is not known whether the Canadian product monographs for all domperidone generics currently list phaeochromocytoma as a contraindication in identical terms. Prescribers should verify the monograph for the specific product dispensed.

The off-label use of domperidone for lactation, which is common in Canada and uncommon in the UK, was not addressed by the MHRA update. Whether the catecholamine-surge mechanism carries any different risk profile in postpartum patients is not established.

Finally, the MHRA's reminder that domperidone can unmask a previously undiagnosed phaeochromocytoma raises a question that no current guideline fully answers: how aggressively should clinicians screen for adrenal tumours before initiating domperidone? The MHRA does not recommend routine screening, and neither does any current Canadian guideline. That question remains open.

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This article is for informational purposes only and is not medical advice. Consult your Canadian healthcare provider about your situation.

Editorial note

Hormone Journal articles are written by our editorial team and reviewed against published clinical guidelines, with a focus on Canadian patient access. We do not promote specific clinics or providers.