This Guidelines summary on intravaginal oestrogen covers contraindications, preparations and dosage, adverse effects, drug interactions, and advice.
Who Should Not Receive Intravaginal Oestrogens?
- The manufacturers of topical oestrogens advise that these preparations are contraindicated in people with:
- Known, past, or suspected breast cancer.
- Known or suspected oestrogen-dependent malignant tumours (such as endometrial cancer).
- Undiagnosed genital bleeding.
- Untreated endometrial hyperplasia.
- Previous or current venous thromboembolism (deep venous thrombosis, or pulmonary embolism).
- Active or recent arterial thromboembolic disease (such as angina and myocardial infarction).
- Known thrombophilic disorders (for example protein C, protein S, or antithrombin deficiency).
- Acute liver disease or a history of liver disease (if liver function tests have failed to return to normal).
- Known hypersensitivity to the active substances or to any of the excipients.
- If use is indicated in these people, consider seeking specialist advice.
What Dose of Intravaginal Oestrogen Should I Prescribe?
- Topical oestrogens should be used in the lowest effective amount to minimize systemic absorption.
- Review at least annually to re-assess the need for continued treatment and to monitor for symptoms of endometrial hyperplasia or carcinoma in women with a uterus.
- For the treatment of atrophic vaginitis in post-menopausal women, licensed doses for intravaginal oestrogen preparations are:
- Intravaginal cream:
- Ovestin® (1 mg estriol in 1 gram cream) — insert one applicatorful daily for a maximum of 4 weeks, reducing to one applicatorful twice a week.
- Vaginal gel:
- Blissel® (50 micrograms estriol in 1 gram vaginal gel) — insert one applicator dose daily for 3 weeks, reducing to one applicator dose twice a week. Reassess after 12 weeks.
- Vaginal tablets:
- Vagifem® vaginal tablets (estradiol 10 micrograms)— insert one vaginal tablet daily for 2 weeks then reduce to one vaginal tablet twice a week.
- Vaginal pessary:
- Imvaggis® vaginal pessary (contains 0.03 mg estriol) — insert one vaginal pessary daily for the first 3 weeks, reducing to one vaginal pessary twice a week.
- Vaginal ring:
- Estring® (releasing approximately 7.5 micrograms of estradiol over 24 hours) — insert the ring into the upper third of the vagina. The ring is then worn continuously for 3 months before replacing with a new ring. Maximum duration of continuous treatment is 2 years.
What Adverse Effects of Intravaginal Oestrogens Should I be Aware Of?
- The British National Formulary advises that the endometrial safety of long-term or repeated use of topical vaginal oestrogens is uncertain.
- Consequently, treatment should be interrupted at least annually to re-assess the need for continued treatment. If bleeding or spotting appears at any time during treatment, the reason should be investigated. Investigations may include endometrial biopsy to exclude endometrial malignancy.
- Other adverse effects reported by the manufacturers of intravaginal oestrogens include vulvovaginal discomfort, headache, abdominal pain, nausea and vomiting, and oestrogen-related adverse events (for example breast pain, postmenopausal bleeding).
What are the Key Drug Interactions with Intravaginal Oestrogens?
- Manufacturers of some intravaginal oestrogen preparations advise that due to vaginal administration and minimal systemic absorption, clinically relevant drug interactions are unlikely, but interactions with other locally applied vaginal treatments should be considered
What Advice Should I Give to Someone Prescribed Intravaginal Oestrogen?
- Advise the woman that:
- Topical oestrogens should be used in the lowest effective dose to minimize systemic absorption.
- Medical advice should be sought if she experiences breakthrough bleeding or spotting at any time during treatment.
- Warn the woman that certain intravaginal oestrogen preparations can damage contraceptive condoms and diaphragms.