Estring

Estring is used by post-menopausal women who have atrophic vaginitis.

What is Estring?

Estring is a vaginal delivery system. It comprises a vaginal ring containing the active constituent oestradiol hemihydrate. Oestradiol is a form of oestrogen, a female hormone that is mainly produced in the ovaries. Together, Estring vaginal delivery system and its constituents provide a hormone replacement therapy (HRT).

A woman’s ovaries steadily produce less oestrogen as they reach the age of menopause (around 45–50 years). After the menopause, the ovaries produce only very low levels of oestrogen. The decline in oestrogen results in changes in the vagina, whereby vaginal tissues become drier, thinner, more fragile, and inflamed (a condition known as atrophic vaginitis). Such symptoms often cause sexual intercourse to become painful. Additionally, the normal vaginal acidity and flora alter, which increases the risk of vaginal and urinary tract infections.

ESTRING vaginal delivery system provides a treatment for atrophic vaginitis, which is more common after the menopause. It works by delivering oestradiol direct to the vagina, thus maintaining the required levels of oestrogen to alleviate these symptoms.

Buy ESTRING Online

The Online Clinic can prescribe ESTRING for female patients who meet the prescribing criteria. Please complete the online form to start the process.

How to use Estring

Instructions on how to use Estring vaginal delivery system are provided in the medicine pack. Wash your hands before and after inserting Estring vaginal delivery system. When inserting into the vagina, stand with one foot on a chair or lie on your back with knees bent. Then, using one hand, open the skin folds surrounding the vagina. Use the other hand to press the ring into an oval shape and push it into the vagina as far as possible, up and back towards the small of the back. If the ring falls out, rinse in warm water and reinsert. To remove Estring vaginal delivery system from the vagina, follow the above process but instead of inserting the ring, hook a finger around the ring and pull carefully down and forward.

Some women are aware of the ring in their vagina when first using Estring vaginal delivery system, but the feeling diminishes over time. The ring remaining inside the vagina is usually acceptable during sexual intercourse, but it can be removed if uncomfortable. Remove the ring when using vaginal preparations. Straining to empty the bowels can cause the ring to move down in the vagina and become visible. It should be pushed back into the vagina using your finger. However, remove the ring first if you are constipated or of straining is needed to empty the bowels.

The full effect of the medicine may take several weeks but, as it starts to work there can be an increase in vaginal lubrication (similar to before the menopause). Every ring is used continuously for three months, before replacing with a new ring. Symptoms may return after approximately three weeks if use of the ring is stopped. Continuous therapy is recommended for up to two years. The doctor will prescribe HRT at the lowest dose to relieve symptoms and only for as long as the benefits outweigh the risks.

At least once-yearly check-ups with a doctor and routine screening for breast cancer and cervical cancer by National screening programmes are recommended for women using the Estring vaginal delivery system. Women should also check their breasts regularly and report any changes to a doctor.

Who can use Estring?

Estring is for post-menopausal women. Women who are pregnant or breast feeding should not use the ring. Women who become pregnant should remove the ring and contact a doctor immediately. Children also should not use the ring.

Estring is not a method of contraception. Therefore, you may become pregnant if you had a menstrual period within the last 12 months and/or you are 50 years of age or younger (i.e., of childbearing age).

Before using Estring you should discuss your medical history and current conditions with a doctor – there are many conditions that prevent or limit its use. Your health, and the risk and benefits of HRT must be discussed and evaluated to check that you can safely use Estring.

Estring should not be used if you have one or more of the medical conditions below. Neither must the ring be used if any of these conditions appear while using the ring – the ring must be removed and a doctor consulted.

• Allergy to oestradiol, other similar hormone replacement therapies, or other Estring constituents
• Oestrogen-sensitive cancer, such as womb cancer.
• Have/have ever had/are suspected of having breast cancer
• Overgrowth of the womb lining (untreated endometrial hyperplasia)
• Vaginal bleeding that your doctor does not know about
• Porphyria, a hereditary blood disorder
• Blood clots that block blood vessels, such as those in the lungs (pulmonary embolism) and legs (deep vein thrombosis)
• Previous/current blocked arteries, which could cause cardiovascular conditions (e.g., angina or heart attack)
• Blood clotting disorder increasing your blood’s tendency to clot (e.g., protein C, protein S, or antithrombin deficiency).
• Previous/current liver disease where liver function tests are still abnormal

Before using Estring, the doctor will want to know if you have or have had in the past any of the conditions listed below, or if these conditions worsen or come back:

• A family history of cancer, especially breast cancer
• A history of endometrial hyperplasia (overgrowth of the womb lining)
• Endometriosis (womb tissues growing outside of the womb)
• Uterine fibroids (growths in the womb)
• Vaginal discomfort, bleeding or pain
• Vaginal shortening and narrowing due to surgery or vaginal atrophy
• A prolapse or have had an operation for prolapse
• Are at risk factors for blood clots in the veins (e.g., pulmonary embolism or deep vein thrombosis)
• High blood pressure
• Are on long term steroid therapy or have adrenal gland disorders (e.g., Cushing’s disease)
• Fluid retention due to kidney or heart problems
• Hereditary and acquired angioedema (build-up of fluid in the skin)
• Liver disease or tumours
• High blood levels of triglycerides (a fat)
• Gallstones
• Diabetes
• Migraine or severe headache
• Seizures
• Autoimmune disease, systemic lupus erythematosus
• Hearing problems due to otosclerosis (scarring in the ear)
• Asthma

Estring must be stopped (and, if possible, the ring removed) and a doctor consulted immediately if any of the following occur:

• Difficulty or pain when removing the ring – rarely the vaginal ring becomes attached to the vaginal wall and needs to be surgically removed
• Development of any of the conditions mentioned above
• Jaundice (yellow skin or eye whites).
• An allergic reaction (symptoms include swelling of the face, tongue and/or throat, difficulty swallowing, difficulty breathing, and/or hives)
• A large increase in blood pressure (symptoms include dizziness, headache, tiredness)
• Migraine-like headaches for the first time
• You get pregnant or want to breastfeed a baby
• A blood clot (signs include red, painful swelling of the legs, sudden chest pain, and/or breathing difficulty)

All medicines, including those past, current and future, should be discussed with a doctor. Especially, anticonvulsants anti-infectives (rifampicin, rifabutin), HIV medicines, and herbal medicines containing St. John’s wort.

Estring side effects

When women use HRT they are at increased risk of certain conditions than when they do not use HRT. These include cancer of the breast, womb, and ovaries; blood clots in veins; having a stroke; and memory loss if HRT is started after 65 years of age.

Of these, the following risks are lower for Estring and other HRTs that are administered via the vagina than for HRT that are transported in the blood: ovarian cancer, blood clots in veins, stroke, and memory loss (if started over the age of 65).

Common side effects reported with using the ESTRING vaginal delivery system include: infection and itching inside and around the vagina, awareness of the ring in the vagina or pressing on the bladder/rectum, abdominal pain or discomfort, pain when passing urine, urinary tract infection, skin itching, and increased sweating. However, these effects are reported more frequently in untreated post-menopausal women.

Uncommon side effects reported with using the ESTRING vaginal delivery system include: vaginal inflammation, and/or thrush; changes in menstrual flow, vaginal discharge, libido, and/or mood; blood clots (leg or lungs) nausea, abdominal pain and/or bloating, anxiety; headache/migraine; dizziness; gallbladder disease; skin discoloration (pregnancy patches); increased hair growth; and/or face or ankle swelling.

References

eMC. Patient leaflet (PIL). ESTRING® 7.5 microgram/24 hours, vaginal delivery system. Available from: https://www.medicines.org.uk/emc/product/1083/pil#about-medicine

Flores SA, Hall CA. Atrophic Vaginitis. [Updated 2022 Oct 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK564341/

Hall JE. Endocrinology of the Menopause. Endocrinol Metab Clin North Am. 2015 Sep;44(3):485-96. doi: 10.1016/j.ecl.2015.05.010.

World Health Organization. Menopause. 2022. Available from: https://www.who.int/news-room/fact-sheets/detail/menopause