Zitazonium

Zitazonium is an anti-estrogenic drug, belongs to the category of antitumor agents and hormonal antagonists.

Indications Zitazonium

It is used in the following cases:

• in the treatment of breast cancer in the later stages of the disease, and also in the postoperative period (as an adjuvant drug in people with breast cancer);
• postmenopausal women with metastatic breast cancer. In people with estrogen-positive tumors, tamoxifen may be an alternative to ovarian radiation or oophorectomy;
• to eliminate infertility (anovulatory form of pathology).

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Release form

Release in tablet form - inside blister packs in the amount of 10 pieces. There are 3 blister plates in a pack.

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Pharmacodynamics

Tamoxifen forms stable complexes by irreversible synthesis with estrogen endings. As a result, the processes of estradiol synthesis with nerve endings are suppressed – this is how the active component of the drug often has an anti-estrogenic effect.

High concentrations of the drug allow to suppress the process of formation of progesterone receptors. As a result, the growth and development of the tumor stimulated by the secreted estrogens slows down.

Pharmacokinetics

After oral administration, the substance is quickly absorbed in the gastrointestinal tract. The drug reaches peak plasma levels after 4-7 hours. With constant use of the drug, its blood levels increase all the time, reaching an equilibrium state after 4 weeks.

The drug undergoes intensive hepatic metabolism. The main breakdown product of the substance (N-desmethyltamoxifen) has medicinal activity. The half-life of tamoxifen ranges from 91 to 156 hours. Excretion of the drug occurs mainly with feces.

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Dosing and administration

When treating breast cancer at the initial stage, it is necessary to take 20 mg of the drug per day. Women in the late stages of the pathology are allowed to take 30-40 mg per day. In this case, adjuvant treatment often continues for about 3-5 years or until the moment when, due to the progression of the disease, it is necessary to switch to palliative therapy.

Treatment regimens for infertility treatment.

Before starting treatment, it is necessary to make sure that there is no pregnancy. The duration of the course and the dose cannot be prescribed in advance - when selecting, it is necessary to take into account the tolerance indicators of a particular patient.

Scheme No. 1: daily intake of 20 mg of the drug (during the period of the 2nd-5th days of the menstrual cycle). In this case, it is necessary to constantly monitor any changes in ovarian function. Women with an irregular cycle can start taking the drug on any day. If there is no ovulation induction as a result of such therapy, it is allowed to increase the dosage in accordance with the rules specified below.

Scheme No. 2: if necessary, the daily dose can be increased to 40-80 mg (with 1-2 doses per day). If a woman starts menstruating, a new course should be started on the 2nd day of the new cycle. If the cycle is irregular and the desired medicinal effect is not achieved (and if menstruation does not start), it is necessary to wait 45 days before starting a repeat therapeutic course.

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Use Zitazonium during pregnancy

Zitazonium should not be used during pregnancy.

Contraindications

The drug is prohibited to be prescribed in the following cases:

• the presence of intolerance to the active component of the drug (tamoxifen) or all its other components;
• breastfeeding period;
• severe problems with liver function;
• history of or ongoing thromboembolic disease.

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Side effects Zitazonium

Using tablets may cause the following side effects:

• dysfunction of the sensory organs and the nervous system: the appearance of dizziness, cataracts, headaches, corneal damage, depression, a feeling of confusion or fatigue, visual impairment and the development of retinopathy;
• manifestations in the cardiovascular system, and in addition to this, disorders of homeostasis and the hematopoietic process: the development of thromboembolism, thrombocytopenia or thrombophlebitis, and in addition, transient leukopenia;
• Gastrointestinal tract lesions: the occurrence of nausea, abdominal pain, vomiting, the development of constipation and severe forms of liver disorders (hepatitis or cholestasis), as well as loss of appetite and increased liver enzyme levels;
• dysfunction of the urogenital system: the appearance of vaginal discharge or bleeding, the development of amenorrhea and a curable tumor in the ovaries (cystic type), fluid retention, as well as irregularity of the menstrual cycle in women in the premenopausal period;
• allergy symptoms: the appearance of a rash on the surface of the skin and itching in the genital area;
• others: pain in the area of the tumor or in the bones, development of alopecia or hypercalcemia, tumor growth in the soft tissue area (noticeable erythema is observed in the affected areas and in the areas around them). The temperature also rises, and a feeling of heat that comes in fits and starts occurs. As a result of prolonged use, changes in the endometrium may occur (manifestations include polyps, hyperplasia, and uterine fibroids); cancer of the uterine body is observed sporadically.

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Overdose

Signs of intoxication: transient neurotoxicity in acute form (appearance of tremor, dizziness, development of hyperreflexia and gait instability). Such disorders disappear several days after discontinuation of therapy. Zitazonium does not cause incurable disorders in the body.

There is no specific antidote for the medication. If there is a suspicion that an overdose has occurred, standard symptomatic and supportive therapy procedures should be followed.

Interactions with other drugs

Zitazonium is prohibited to be combined with the drug allopurinol (anti-gout drug), and in addition with substances that reduce blood viscosity and prevent the formation of blood clots (for example, coumarin derivatives).

Caution is required when using the drug in combination with bromocriptine - as a result, the serum level of both the active component and the drug breakdown product may increase. It is also used with caution together with cytotoxic agents - such a combination increases the risk of thromboembolic complications.

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Storage conditions

Zitazonium should be kept in places where sunlight does not penetrate, and inaccessible to children. Temperature conditions are within 15-25°C.

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Shelf life

Zitazonium can be used for a period of 4 years from the date of manufacture of the drug.

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