Aerodiol nasal spray containing estradiol hemihydrate 150µg per spray has been launched by Servier Laboratories The product is licensed for replacement therapy for oestrogen deficiency symptoms in postmenopausal women. The company says that the usual recommended dose for the initiation of treatment is 300µg (administered as one spray into each nostril) daily as a single dose

How does it work?

Estradiol hemihydrate is a naturally occuring form of the main female sex hormone, oestrogen.

Certain parts of the body such as the vagina, bones and breasts rely on oestrogen to function normally. When the levels of oestrogen decrease, as happens during the menopause, these tissues can slowly degenerate. In addition, low levels of oestrogen can cause distressing symptoms such as hot flushes, mood swings and vaginal dryness.

Oestrogen (in this case in the form of estradiol hemihydrate) is supplemented to help reduce distressing symptoms of the menopause. This is known as hormone replacement therapy (HRT).

In women with an intact womb, oestrogen stimulates the growth of the womb lining (endometrium). This can lead to endometrial cancer if the growth is unopposed. For this reason it is essential that women with an intact womb be given a progestogen with this medicine, to oppose oestrogen's effect on the womb lining. The progestogen is taken for at least 12 days each month, which mimics the fluctuating levels of oestrogen and progesterone that occur in the natural menstrual cycle. This results in the womb lining being shed as a menstrual period at the end of each month. 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.

There are two main types of HRT. One gives a continuous daily dose of hormones, whereas the other uses the concept of 'cycle therapy'. This nasal spray can be used as either.

In cycle therapy the nasal spray is used daily for 21 to 28 days, followed by a 2 to 7 day treatment free period. For women who have not had a hysterectomy, a progestogen component must be taken in addition to the nasal spray for at least the last 12 days before the treatment free period.

In continuous therapy the nasal spray is used continuously with no breaks. If a progestogen is needed, it is added for at least 12 days every month.