5. Genitourinary Syndrome of Menopause (GSM)
Pedagogy: This lesson uses treatment-algorithm construction — building a stepped approach from non-hormonal to hormonal GSM management with clear safety parameters for special populations.
Learning Objectives
- List vaginal oestrogen formulations available in the UK: creams, pessaries, rings, gels
- Describe vaginal prasterone (DHEA) and ospemifene as alternative options
- State that vaginal oestrogen is safe long-term and does not require progestogen
- Discuss the safety of vaginal oestrogen in breast cancer survivors
Key Facts
Non-Hormonal Options (First Step)
Vaginal moisturisers (e.g. Replens, YES VM): applied regularly (2-3 times/week), not just before intercourse. Water- or silicone-based lubricants for intercourse. These provide symptomatic relief but do not reverse the underlying atrophy (1).
Vaginal Oestrogen (Mainstay of Treatment)
| Preparation | Dose | Regimen |
|---|---|---|
| Vagifem (estradiol tablets) | 10 mcg | Nightly x 2 weeks, then twice weekly |
| Estriol cream (Ovestin) | 0.1% | Nightly x 2 weeks, then twice weekly |
| Estriol cream (Blissel) | 50 mcg/g | Nightly x 3 weeks, then twice weekly |
| Imvaggis pessary | 0.03 mg estriol | Nightly x 3 weeks, then twice weekly |
| Estring (vaginal ring) | 7.5 mcg/24h | Insert, replace every 3 months |
Long-term use: symptoms frequently recur on cessation. Twice-weekly maintenance can continue indefinitely. Progestogen is NOT required. Some women on systemic HRT still need additional vaginal oestrogen (1,2).
Other Options
Vaginal prasterone (Intrarosa): DHEA pessary, 6.5mg nightly. Converted locally to oestrogen and testosterone. Licensed for GSM. Ospemifene: oral SERM, 60mg daily. Licensed for moderate-to-severe dyspareunia. Less commonly used in UK. Laser therapy: limited evidence; NICE makes no recommendation (1).
Safety in Breast Cancer Survivors
Low-dose vaginal oestrogen is not associated with increased breast cancer recurrence in most guidelines. However, oncologist involvement is necessary if there is a history of breast cancer, particularly in women on aromatase inhibitors where even minimal systemic absorption may be a concern (2).
Clinical Pearl Vaginal oestrogen can be used long-term — there is no time limit. Symptoms return on cessation. Twice-weekly maintenance is safe indefinitely without progestogen.
Clinical Pearl Some women on systemic HRT still need ADDITIONAL vaginal oestrogen for GSM. The two treatments are complementary, not mutually exclusive.
Case-Based Examples
Case 1: 65-year-old new to vaginal oestrogen — counselling
Presentation: A 65-year-old with vaginal dryness and dyspareunia has never been offered vaginal oestrogen. She is not on systemic HRT. She is anxious about using 'hormones down there.'
Question: How would you counsel her and initiate treatment?
Model Answer: Reassure: vaginal oestrogen is a local treatment with negligible systemic absorption — it is NOT the same as 'going on HRT.' Explain the initiation regimen (e.g. Vagifem: nightly for 2 weeks, then twice weekly). Benefits usually noticed within 4-6 weeks. She does not need progestogen. It can be continued long-term. Common concerns to address: it will not increase breast cancer risk; it is safe for long-term use; she may notice some initial irritation which settles. Add a vaginal moisturiser for additional comfort. Review at 3 months.
Case 2: GSM persisting despite systemic HRT
Presentation: A 54-year-old on transdermal oestradiol 50mcg + Utrogestan 100mg continuous reports VMS are well-controlled but she still has significant vaginal dryness and dyspareunia.
Question: What additional treatment should you offer?
Model Answer: Systemic HRT may not fully resolve GSM in all women. Add vaginal oestrogen (e.g. estriol cream or Vagifem) in addition to her systemic HRT — the two are complementary. No additional progestogen needed for the vaginal component. Also recommend a vaginal moisturiser between oestrogen applications. Review at 3 months. If dyspareunia persists, consider referral for pelvic floor physiotherapy — vulvovaginal pain may develop a secondary musculoskeletal component (vaginismus).
Self-Assessment Questions
PLAB/MLA Vaginal oestrogen duration
How long can vaginal oestrogen be used for GSM?
A. Maximum 1 year
B. Maximum 5 years
C. Indefinitely — there is no time limit
D. Only during the first 5 years of menopause
Answer: C. Vaginal oestrogen can be used long-term/indefinitely. Symptoms recur on cessation. No progestogen required.
MRCGP GSM despite systemic HRT
A woman on adequate systemic HRT still has vaginal dryness. What should you do?
A. Increase the systemic oestrogen dose
B. Add vaginal oestrogen — systemic HRT may not fully resolve GSM
C. Switch to oral oestrogen
D. Refer to gynaecology
Answer: B. Systemic HRT does not always fully resolve GSM. Adding vaginal oestrogen is appropriate and commonly needed.
Professor Vaginal prasterone: mechanism and evidence
Compare the mechanism and evidence base for vaginal prasterone (DHEA) versus vaginal oestrogen for GSM.
A. They are identical
B. Prasterone is converted locally to both oestrogen and testosterone via intracrine metabolism; RCT evidence shows improvement in dyspareunia, but head-to-head comparisons with vaginal oestrogen are lacking
C. Prasterone is superior to vaginal oestrogen
D. Prasterone has no evidence base
Answer: B. Vaginal prasterone (Intrarosa, 6.5mg nightly) is a DHEA pessary metabolised intracellularly by steroidogenic enzymes in vaginal tissue to oestrogens and androgens. The dual hormone production may offer advantages for sexual function (androgen component). Phase 3 RCTs (ERC-238 trials) demonstrated improvement in vaginal dryness, dyspareunia, and vaginal pH. However, no head-to-head trial with vaginal oestrogen has been conducted. Theoretical advantages include: dual hormonal mechanism; and avoidance of the term 'oestrogen' which may reassure breast cancer survivors (though local oestrogen IS produced). Cost is higher than generic vaginal oestrogen.
Take-Away Messages
- First step: vaginal moisturisers and lubricants (symptomatic, do not reverse atrophy)
- Vaginal oestrogen is the mainstay: multiple formulations available; nightly x 2-3 weeks then twice weekly
- Safe long-term; no progestogen required; can be added to systemic HRT
- Vaginal prasterone (DHEA) and ospemifene are alternatives with different mechanisms
- Breast cancer survivors: low-dose vaginal oestrogen is generally considered safe; oncology involvement essential with aromatase inhibitors