Premarin® | Premarin (Estrogens / Oestrogens) - 0.625mg (28 Tablets)

How does Premarin (Estrogens/Oestrogens) work?

Premarin tablets contain conjugated oestrogens as the active ingredient. These are a naturally occuring form of the main female sex hormone, oestrogen.

Womens ovaries gradually produce less and less oestrogen in the period up to the menopause, and oestrogen blood levels decline as a result. The declining levels of oestrogen can cause distressing symptoms, such as irregular periods, hot flushes, night sweats, mood swings and vaginal dryness or itching.

Oestrogen (in this case in the form of conjugated oestrogens) can be given as a supplement to replace the falling levels in the body and help reduce these distressing symptoms of the menopause. This is known as hormone replacement therapy (HRT). HRT is usually only required for short-term relief from menopausal symptoms and its use should be reviewed at least once a year with your doctor.

Premarin tablets are a continuous, oestrogen-only form of HRT. As they only contain oestrogen, they are most suitable for women who have had a hysterectomy. Women who have not had a hysterectomy should also be prescribed a progestogen medicine to take with this medicine for the last 12 to 14 days of each 28-day pack. This is because oestrogen stimulates the growth of the womb lining (endometrium), which can lead to endometrial cancer if the growth is unopposed. A progestogen is given to cause a monthly withdrawal bleed, which opposes oestrogen's effect on the womb lining. This reduces the risk of endometrial cancer, though it does not eliminate this risk entirely. This known as combined HRT. If a woman has had her womb surgically removed (a hysterectomy), endometrial cancer is not a risk, and a progestogen is not necessary as part of HRT (unless the woman has a history of endometriosis).

HRT is also sometimes used to prevent osteoporosis in postmenopausal women. The declining level of oestrogen at menopause can affect the bones, causing them to become thinner and more prone to breaking. Oestrogen supplements help prevent bone loss and fractures that may occur in women in the years after menopause.

However, in December 2003, a review of the available evidence on the risks and benefits of HRT by the Medicines and Healthcare products Regulatory Agency (MHRA) and the Committee on Safety of Medicines (CSM) in the UK, concluded that the risks of using HRT long-term to prevent osteoporosis in women aged over 50 years exceed the benefits. As a result, this medicine should not be used as a first-line option for preventing postmenopausal osteoporosis in women over 50. However, it may be used as a second-line option for women at high risk of fractures who cannot take other medicines that are licensed for this purpose.

Women considered to be at risk of developing fractures following the menopause include those who have had an early menopause, those with a family history of osteoporosis, those who have had recent prolonged corticosteroid therapy (eg prednisolone), those with a small thin frame, and smokers.

You can read more about the risks and benefits of HRT and other medicines for preventing osteoporosis in the factsheets about menopause and osteoporosis linked below.

What is Premarin (Estrogens/Oestrogens) used for?

• Hormone replacement therapy to relieve symptoms of the menopause
• Second-line option for preventing osteoporosis in postmenopausal women who are at high risk of fractures and cannot take other medicines licensed for preventing osteoporosis.

Premarin (Estrogens/Oestrogens) Side Effects

• Breakthrough bleeding and spotting
• Breast pain, tenderness or enlargement
• Headache/migraine
• Gut disturbances, such as nausea, abdominal pain, bloating, flatulence, indigestion
• Leg cramps
• Fatigue
• Weight changes
• Vaginal thrush
• Depression
• Anxiety
• Dizziness
• Changes in sex drive
• Rise in blood pressure
• Gall bladder disease
• Swelling of the ankles due to to fluid retention (peripheral oedema)
• Skin reactions such as rash and itch
• Steepening of corneal curvature which may make contact lenses uncomfortable.
• Premenstrual-like symptoms
• Disturbance in liver function
• Irregular brown patches on the skin, usually of the face (chloasma)
• Blood clots in the blood vessels (eg, DVT, pulmonary embolism, heart attack, stroke)