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20/72 Oxybutynin for the treatment of vasomotor symptoms associated with menopause




The aim of the HTA Programme is to ensure that high quality research information on the effectiveness, costs and broader impact of health technology is produced in the most efficient way for those who use, manage, provide care in or develop policy for the NHS. Topics for research are identified and prioritised to meet the needs of the NHS. Health technology assessment forms a substantial portfolio of work within the National Institute for Health Research and each year about fifty new studies are commissioned to help answer questions of direct importance to the NHS. The studies include both primary research and evidence synthesis.

Research question

What is the clinical and cost-effectiveness of oxybutynin in women with vasomotor symptoms associated with menopause and who are not taking hormone replacement therapy? 

  1. Intervention: Oxybutynin. Dose, duration and formulation to be defined by applicants. 
  2. Patient group: Women with vasomotor symptoms (hot flushes, hot flashes, night sweats) associated with menopause who have opted for pharmacological treatment that doesn’t include hormone replacement therapy (HRT). Study should be adequately powered to address outcomes in the two main groups of women, (i) those in whom HRT is contraindicated and (ii) those who choose not to take it.
    Applications are encouraged which include recruitment from geographic populations with high disease burden which have been historically underserved by research activity in this field and should be diverse to include all women who may be eligible for the treatments.
  3. Setting: Primary care.
  4. Comparator: Commonly prescribed non-HRT pharmacological treatment. To be defined by applicants.
  5. Study design: A randomised controlled trial with an internal pilot phase to test the ability to recruit and randomise. Clear stop/go criteria should be provided to inform progression from pilot to full trial.
  6. Important outcomes: Vasomotor symptom control (including reduced frequency and severity).
    Other outcomes: Other menopausal symptoms; patient experience; anticholinergic treatment burden; adverse effects; cost-effectiveness; quality of life and occupational outcomes.
  7. Minimum duration of follow-up: 12 months.
    Longer-term follow up: If appropriate, researchers should consider obtaining consent from participants to allow future follow up through efficient means (such as routine data) as part of a separately funded study. 


Menopause is a biological stage in a woman’s life when she is no longer fertile and it is marked by the absence of menstrual bleeding. As many as 75% of menopausal women experience vasomotor symptoms (VMS) which include hot flushes (or flashes), night sweats, palpitations and headache. Hormone replacement therapy (HRT) is the most effective treatment for VMS and is the first line treatment for women requiring pharmacological management as recommended by the National Institute for Health and Care Excellence (NICE). However, HRT may be contra-indicated in some women, such as those who have or have had breast cancer, or they or their GP may be concerned about potential harms associated with its use. The most frequently considered non-hormonal therapies for the management of VMS are selective serotonin reuptake inhibitors (SSRI) and clonidine. Evidence on the efficacy of these drugs indicate they are less effective than oestrogen therapy and associated with greater side effects.

One of the less frequently used drugs for VMS is oxybutynin chloride. It is an antimuscarinic, anticholinergic agent with antispasmodic activity and known for its action of relaxing bladder smooth muscle to treat urinary incontinence. There is some initial evidence that extended-release oxybutynin chloride may be an effective non-hormonal therapy for moderate-to-severe VMS in postmenopausal women. Further studies are warranted to establish the clinical and cost-effectiveness of this drug to help guide UK clinical practice.

Additional commissioning brief background information

A background document is available that provides further information to support applicants for this call. It is intended to summarise what prompted the call and the existing evidence base, including relevant work from the HTA and wider NIHR research portfolio. It was researched and written on the basis of information from a search of relevant sources and databases, and in consultation with a number of experts in the field. If you would like a copy please email

Making an application

If you wish to submit a Stage 1 application for this call, the online application form can be found on the Funding opportunities page.  To select this call, use the filters on the right of the screen or search using the call name and/or number.

Your application must be submitted on-line no later than 1pm on the 2nd December 2020. Applications will be considered by the HTA Funding Committee at its meeting in January 2021.

Guidance notes and supporting information for HTA Programme applications are available by clicking the links.

IMPORTANT: Shortlisted Stage 1 applicants will be given eight weeks to submit a Stage 2 application. The Stage 2 application will be considered at the Funding Committee in May 2021.

Applications received electronically after 1300 hours on the due date will not be considered.

For commissioned topics, the Programme strongly discourages the practice of the same co-applicant joining more than one competing team. There may be unusual circumstances where the same person could be included on more than on application eg a lead from a named charity or a unique national expert in a condition.

For such exceptions (i) each application needs to state the case as to why the same person is included (ii) the shared co-applicant should not divulge application details between teams and (iii) both teams should acknowledge in their application that they are aware that one of their co-applicants is part of a competing application and that study details have not been shared. 

Should you have any queries please contact us