Parliamentary Reply: 12,401,593 prescriptions for mirtazapine were issued last year – and reports of particular adverse effects. Letter from Minister (Lord) Nick Markham addressing concerns about “post-SSRI sexual dysfunction.”

Mar 26, 2024 | News

Lord Markham, the Department of Health and Social Care, has provided the following answer to your written parliamentary question (HL3163):

Question by Lord Alton of Liverpool:
To ask His Majesty’s Government how many prescriptions for mirtazapine were issued in each year since 2014; how many Yellow Card reports of sexual dysfunction and persistent sexual dysfunction the MHRA received for mirtazapine in each year since 2014; and what consideration NHS England has given to adding sexual dysfunction as a side effect on the patient information leaflets for mirtazapine. (HL3163)

Tabled on: 11 March 2024

Lord Markham:

The following table shows the total number of items issued for mirtazapine, each year since 2014 to 2023:

Time PeriodTotal items issued

Source: Data was provided by the NHS Business Services Authority, using the British National Formulary chemical substance mirtazapine

Note: Items have been dispensed, but not necessarily prescribed, in England.

The Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for ensuring medicines, medical devices, and blood components for transfusion meet applicable standards of safety, quality, and efficacy. The MHRA rigorously assesses available data, including from the Yellow Card scheme, and seeks advice from their independent advisory committee, the Commission on Human Medicines, where appropriate to inform regulatory decisions.

The MHRA has received a total of 46 Yellow Card reports of sexual dysfunction related reactions suspected to be associated with mirtazapine, four of which include information that suggest the suspected adverse reactions persisted after mirtazapine was withdrawn. The following table shows the number of Yellow Card reports of suspected mirtazapine related sexual dysfunction, and reports of sexual dysfunction that persisted after the drug was withdrawn, each year from 2014 to 2024:

YearReports of sexual dysfunctionReports of sexual dysfunction that continued after mirtazapine was withdrawn

Source: data provided by the MHRA.

It is important to note that the inclusion of a particular report on the MHRA’s system does not necessarily mean that the adverse reactions reported have been caused by the suspect drug. Additionally, the number of reports received should not be used as a basis for determining the incidence of a reaction, as neither the total number of reactions occurring, nor the number of patients using the drug, is known.

The MHRA continuously monitors the safety of medicines on the United Kingdom’s market, including mirtazapine. Reports of suspected adverse reactions are reviewed weekly by a multidisciplinary team as part of the MHRA’s signal detection process. The term signal is used to define any suspected adverse reaction or potential safety concern that requires further evaluation.

Responsibility for adding a side effect to the product information leaflet sits with the MHRA. The product information for mirtazapine reflects the data currently available, and does not include sexual dysfunction as a possible side effect. However, data from Yellow Card reports and other sources such as published studies and periodic safety assessments are kept under continuous review by the MHRA. The marketing authorisation holder has recently submitted the latest periodic safety update report to the MHRA, and this will be carefully assessed. If there is sufficient evidence and associated data about the potential to experience sexual dysfunction as a side effect, the patient information for mirtazapine can be updated.

Date and time of answer: 26 Mar 2024 at 14:30.


26 March 2024
Dear Lord Alton
Thank you for your most recent email of 13 February 2024 sharing important information from the members of a charity raising their concerns about “post-SSRI sexual dysfunction.”
Issues relating to sexual dysfunction, particularly symptoms which may persist long term despite discontinuing the medicine, are understandably a significant concern for patients.
In May 2019, MHRA was an integral participant in a Europe-wide review of these risks. The conclusion of this review was that information provided to healthcare professionals and patients for all SSRIs should be updated to inform them that reports had been received of long-lasting sexual dysfunction where the symptoms continue despite discontinuation of the SSRIs antidepressant. Changes to the product information for all SSRIs/SNRIs have been implemented and the patient information leaflet now states:
“Medicines (SSRIs) may cause symptoms of sexual dysfunction. In some cases, these symptoms have continued after stopping treatment”
The issue of sexual dysfunction that continues after stopping SSRIs is being monitored by the MHRA through all available information including review of the Periodic Safety Update Single Assessment (PSUSA) reports which contain regular appraisals of the wider scientific literature in addition to spontaneous reports. The MHRA is also aware of ongoing work by several patient charities to increase awareness and improve support for patients.
An expert working group of the Commission on Human Medicines is being established to review evidence from patients and families and make recommendations to the Commission on a range of antidepressant risks and it is anticipated a review of the evidence for sexual dysfunction will be undertaken as part of this work in 2024.
As you may know, the National Institute for Health and Care Excellence (NICE) is the independent body responsible for developing evidence-based guidance for the NHS, in line with its established methods and processes. NICE guidelines are developed by experts based on a thorough assessment of the available evidence and through extensive engagement with stakeholders. NICE guidelines provide recommendations on best practice in terms of both the effectiveness and cost-effectiveness of interventions and services. Guidelines describe best practice but, unlike NICE’s health technology appraisals, are not mandatory, although health and care commissioners are expected to take them fully into account. NICE published guidelines in June 2022 titled, Depression in adults: treatment and management. These guidelines advise that when offering a person medication for the treatment of depression, the clinician should discuss and agree a management plan with the patient. This should include discussing possible side effects and withdrawal effects and effects on sexual function are specifically referenced for discussion. NICE also recommends that a review should take place between 2- 4 weeks to monitor for side effects/ harms.
I hope this information is helpful and reassures you that action is being taken to monitor for, investigate and raise awareness of the possible risk of long-lasting sexual dysfunction with antidepressants. Let’s see what the Commission on Human Medicines working group recommends and catch-up after then if helpful.
With my very best wishes,

Lord David Alton

For 18 years David Alton was a Member of the House of Commons and today he is an Independent Crossbench Life Peer in the UK House of Lords.

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