Norethisterone

Pharmacological properties

norethisterone is a progestogen. causes secretory transformations in the proliferating endometrium and blocks the secretion of gonadotropin in the pituitary gland, preventing the maturation of follicles and the onset of ovulation.

Pharmacokinetics

Suction. It is well absorbed in the digestive tract. As a result of intensive primary metabolism in the liver and intestinal wall, bioavailability is 50–77%.

Distribution. After taking 0.5; 1 or 3 mg norethisterone C_max in blood plasma is 2–5; 5–10 or 30 ng / ml, respectively, when measured 0.5–4 hours after taking the drug. When prescribed in combination with ethinyl estradiol, it is possible to increase the concentration of the drug in blood plasma, which occurs in the case of repeated administration until an equilibrium state is reached. This is mainly due to the binding of norethisterone to sex hormone-binding globulin (SHBG) and a slowdown in its metabolism.

Biotransformation. Among the metabolites of norethisterone there are many isomers, for example 5α-dihydro-norethisterone and tetrahydro-norethisterone, excreted in the urine in the form of glucuronide conjugates. Part of norethisterone and its metabolites form a bond with the 17β-hydroxy group.

Elimination. A decrease in the concentration of norethisterone in blood plasma is carried out in two phases. T_½ in the first phase lasts 2.5 hours, in the final phase - 8 hours. 80% of the metabolites formed in the liver are excreted in the urine.

Indications

Secondary amenorrhea, endometriosis.

Application

Take the tablets whole with a liquid, without chewing.

The effectiveness of Norcolut tablets may be reduced if the patient forgets to take the tablet as directed. The patient should take only the last missed pill as soon as she remembers, and then continue taking the pill at the usual time the next day.

If contraception is needed, then non-hormonal methods should be used in addition.

Secondary amenorrhea

Any hormonal therapy of secondary amenorrhea can be carried out only after exclusion of pregnancy. In some cases, secondary amenorrhea is caused by prolactinoma, which should be ruled out before starting Norcolut.

A drug containing estrogen is prescribed (for example, for 14 days) before the use of Norcolut is started. After that, Norcolut is taken 1 tablet 1-2 times a day for 10 days. Withdrawal bleeding begins a few days after taking the last pill.

Upon reaching a sufficient level of estrogen production, you can try to stop estrogen therapy and cause cyclic bleeding by taking 1 tablet of Norcolut 2 times a day from the 16th to the 25th day of the cycle.

Endometriosis

Treatment begins between the 1st and 5th day of the cycle with the use of the drug Norcolut 1 tablet 2 times a day. In case of spotting, increase the dose and take Norcolut 2 tablets 2 times a day. After the cessation of bleeding, you can reduce the dose to the initial. The duration of treatment is at least 4-6 months. With continuous daily use of the drug, ovulation and menstruation are absent. After the completion of hormone therapy, withdrawal bleeding occurs.

Contraindications

You can not use the drug Norcolut in the presence of any of the conditions or diseases listed below.

Pregnancy or suspicion of it.

Lactation.

The formation of a blood clot in the veins (thrombosis), for example in the blood vessels of the lower extremities (deep vein thrombosis - DVT) or the lungs (pulmonary embolism - pulmonary embolism).

High risk of venous or arterial thrombosis.

Conditions preceding thrombosis (including transient ischemic attack, angina pectoris), currently or in history.

Migraine with focal neurological symptoms in history.

Diseases associated with circulatory disorders in the arteries, such as myocardial infarction or stroke, currently or in history.

Diabetes mellitus with vascular complications.

Severe liver disease at present or in the anamnesis, while liver function indicators are not normalized. Symptoms of liver disease may include, for example, ictericity of the skin and / or itching of the whole body.

Dubin-Johnson syndrome, Rotor syndrome, as well as jaundice or cases of severe skin itching during previous pregnancies.

Previous cases of pregnant pemphigoid (pregnant herpes).

Benign or malignant liver tumors are currently or in history.

Malignant tumors that are dependent on the influence of sex hormones (such as mammary glands or genital organs), which are currently or in history.

Hypersensitivity to norethisterone or any of the auxiliary components of the drug.

If any of the above conditions occurs for the first time while taking the drug, you should immediately stop its use and consult a doctor.

Side effects

More often noted in the first months after the start of the drug Norcolut.

Such adverse events have been reported in patients taking norethisterone, although a causal relationship cannot always be confirmed. The following are adverse reactions in the classes of MedDRA organ systems.

Data on the incidence of adverse reactions are based on the results of post-marketing studies and scientific literature.

* When used according to the indications of "endometriosis".

The frequency is unknown (cannot be determined from the available data) (see SPECIAL INSTRUCTIONS): thromboembolism; tumors of the liver that lead to intra-abdominal bleeding; chloasma; severe headache and migraine or an increase in the frequency of unusually severe migraines, sudden disturbances in perception; first signs of thrombophlebitis or symptoms of thromboembolism; a feeling of pain and constriction in the chest; the appearance of jaundice, the development of hepatitis, itching of the skin, a significant increase in blood pressure.

Dizziness, increased depression, abdominal pain, and cholestasis were also noted.

The drug Norcolut in very high doses can in some cases lead to cholestatic disorders of the liver.

special instructions

To prevent pregnancy, it is necessary to use non-hormonal methods of contraception (barrier).

Before starting or continuing treatment with Norcolut, an individual assessment of the risk / benefit ratio should be made if any of the disorders / risk factors described below are worsened or worsened.

Vascular disorders

Based on epidemiological studies, it has been found that oral administration of ovulation inhibitors containing estrogen / progestogen leads to an increase in the number of cases of thromboembolic disorders. Therefore, it is necessary to take into account the possibility of increasing the risk of thromboembolism, especially in the presence of such diseases in history.

The generally recognized risk factors for venous thromboembolism (VTE) are personal or family history of the disease (VTE in a brother / sister or one of the parents at a relatively young age), age, obesity, prolonged immobilization, extensive surgery, and serious injuries.

Consider the increased risk of thromboembolism in the postpartum period.

Stop treatment immediately if symptoms of arterial or venous thrombosis appear or if it is suspected.

In patients with a history of VTE or a known thrombotic condition, an increased risk of developing VTE is noted.Steroid hormone treatment may increase this risk. Patients with a personal or family history of thromboembolism or recurrent spontaneous abortions should be examined to rule out a tendency to thromboembolism. Patients using anticoagulant therapy should be carefully evaluated for thromboembolic risks before starting progestogen treatment. With prolonged immobilization, elective surgery, especially in the abdominal region, orthopedic surgery on the lower extremities, it is necessary to stop progestin therapy 4-6 weeks before surgery. Continued treatment with progestogens is possible only after a complete restoration of the motor regimen.

Additional refinements based on the partial conversion of norethisterone to ethinyl estradiol

VTE. Epidemiological studies have shown that the incidence of VTE in patients taking oral contraceptives with a low estrogen content (50 μg ethinyl estradiol) is approximately 20 to 40 cases per 100,000 women-years, but this risk assessment varies depending on the progestogen. The data presented can be compared with 5–10 cases per 100,000 women-years in people who do not take oral contraceptives. The use of any combined oral contraceptives (CPC) carries an increased risk of VTE. This increased risk is lower than the risk of VTE associated with pregnancy, which is estimated