Estradiol

Pharmacological properties

estradiol valerate, which is a synthetic 17-estradiol, is chemically and biologically identical to endogenous human estradiol. it compensates for decreased estrogen levels in women during menopause, alleviating the symptoms of menopause in this way. estrogens prevent bone loss that occurs during menopause or after ovariectomy.

The transdermal use of estradiol in combination with medroxyprogesterone acetate helps to reduce the level of total cholesterol without changing the cholesterol level of HDL. The effectiveness of Divigel for correcting a decrease in bone density in the postmenopausal period is the same as when using oral estrogen preparations.

Pharmacokinetics Divigel is an alcohol-based estradiol gel.

When the gel is applied to the skin, alcohol evaporates quickly and estradiol penetrates the skin, entering the circulatory system. Application of the drug to an area of ​​200-400 cm² (the size of one or two palms) does not affect the amount of estradiol absorbed. However, if the drug is applied over a large area, the degree of absorption is significantly reduced. A certain amount of estradiol is retained in the subcutaneous tissue, from where it gradually enters the systemic circulation. Transdermal administration avoids the first stage of hepatic metabolism. For this reason, fluctuations in the concentration of estrogen in blood plasma with Divigel are much less pronounced than with oral estrogens.

During transdermal application of Divigel, plasma concentrations of estradiol were as follows:

During treatment with the drug, the ratio of estradiol / estrone remains at the level of 0.4-0.7, while with oral administration of estrogen it usually decreases to the level of 0.2. A sustained bioavailability is 82% compared with the equivalent oral dose of estradiol valerate.

Divigels metabolism and excretion during transdermal administration are similar to those of natural estrogens.

Indications

Symptoms associated with estrogen deficiency in natural or artificial menopause. for the prevention of postmenopausal osteoporosis with a high risk of fracture, when other drugs for the prevention of osteoporosis are contraindicated or unsuitable.

Application

Dosage. Divigel is a transdermal gel intended for continuous or cyclical treatment. the usual starting dose is 1 g of gel per day, which corresponds to 1 mg of estradiol. the duration of administration and dose is selected by the doctor taking into account the individual characteristics of the patient (depending on the clinical condition, after 2-3 cycles, the dose can be adjusted: from 0.5 to 1.5 g of gel per day, which corresponds to 0.5-1.5 mg estradiol per day).

For patients with an intact uterus, Divigel must be combined with progestogen therapy at intervals of 1 month, using, for example, medroxyprogesterone acetate, norethindrone, norethindrone acetate or dydrogesterone for at least 12-14 days.

Progestogens are not recommended for women after a hysterectomy unless they have been diagnosed with endometriosis.

Patients who have not previously used hormone replacement therapy (HRT) or are switching to Divigel after prolonged combination therapy can start Divigel treatment any day. Patients who switch to Divigel after continuous hormone replacement therapy can start Divigel treatment after the end of the last treatment cycle.

In the treatment of postmenopausal