Honvan — Fosfestrol 120 mg

Honvan is manufactured in the form of tablets for oral use, each containing a strictly calibrated amount of active and auxiliary substances:

• Active Compound: Fosfestrol (as fosfestrol tetrasodium) — 120 mg per tablet.
• Excipients: Lactose monohydrate, maize starch, povidone, magnesium stearate, purified talc, colloidal silicon dioxide, sodium starch glycolate.
• Appearance: Flat-cylindrical tablets. Supplied in cardboard boxes containing either 50 tablets (5 blisters of 10 pieces) or 100 tablets (10 blisters of 10 pieces).

Pharmacodynamics: Fosfestrol is an anti-tumor estrogenic agent. In prostate tissues, it is dephosphorylated under the influence of specific phosphatase, converting into diethylstilbestrol. The drug inhibits the secretion of pituitary gonadotropic hormones, reduces androgen synthesis in the testes, and exerts a direct cytotoxic effect on tumor cells by blocking their mitotic division.

Pharmacokinetics: Following oral intake, it is rapidly absorbed in the gastrointestinal tract. It exhibits a pronounced tropism for prostate tissues. It is metabolized primarily in the target cells and the liver. Excreted from the body as metabolites and conjugates, predominantly by the kidneys in urine and partially via bile.

Honvan 120 mg is used exclusively in uro-oncological practice as prescribed by the treating physician for the management of the following conditions:

• 🔹 Prostate Cancer: Progressive, locally advanced, or metastatic prostate cancer (including hormone-resistant and androgen-independent forms).
• 🔹 Tumor Recurrences: Palliative therapy for prostate cancer recurrences following surgical castration or treatment with other hormonal agents.

The dosing regimen and total duration of hormonal therapy are customized by the uro-oncologist strictly individually, based on the disease stage and PSA level dynamics:

• Recommended Dosage: The initial dose is usually 2–3 tablets (240–360 mg) taken 3 times daily. Upon achieving clinical improvement, the dose is gradually reduced to a maintenance level of 1–2 tablets (120–240 mg) daily.
• Method of Administration: Tablets are swallowed whole orally, independent of food intake, with a sufficient amount of clean water. Chewing or crushing the tablets prior to ingestion is not recommended.
• Dosing Schedule: The daily dose is divided into several administrations at regular intervals. For the convenience of long-term maintenance courses, using the 100-tablet pack is advisable.
• Duration of Treatment: Hormonal therapy is carried out in long, continuous courses. Efficacy control is performed via regular monitoring of PSA levels and enzymes.

The use of Honvan tablets is strictly prohibited in the presence of the following concomitant pathologies or history restrictions:

• ⛔ Hypersensitivity: Individual intolerance to fosfestrol, diethylstilbestrol, or any excipient components of the medication.
• ⛔ Thromboembolic Disorders: Acute thrombophlebitis, pulmonary embolism, severe forms of varicose veins in the stage of decompensation.
• ⛔ Cardiovascular Diseases: Severe decompensated heart conditions, recent myocardial infarction or stroke, severe uncontrolled arterial hypertension.
• ⛔ Hepatic Impairment: Marked hepatic insufficiency, acute hepatitis, liver tumors. The drug is also not intended for use in women or children.

Concomitant use of fosfestrol with other medicinal products requires cautious monitoring due to potential pharmacodynamic changes:

• ❌ Oral Anticoagulants: Estrogens reduce the therapeutic efficacy of coumarin anticoagulants, increasing the risk of thrombus formation and requiring dose adjustments.
• ❌ Microsomal Oxidation Inducers: Rifampicin, barbiturates, and phenytoin may accelerate drug metabolism in the liver, substantially decreasing its anti-tumor effect.
• ⚠️ Hepatotoxic Drugs: Co-administration with other drugs that place a load on the liver increases the risk of developing toxic lesions of the hepatobiliary system.

The specificity of the drug's indications completely excludes its use in female patients; however, general toxicological aspects must be noted:

• Target Population: Honvan is developed exclusively for the therapy of prostate cancer in men and is never applied to women.
• Reproductive Toxicity: The active metabolite (diethylstilbestrol) possesses a pronounced teratogenic, mutagenic, and embryotoxic effect. Exposure to the substance in a female organism during pregnancy causes severe fetal developmental malformations.
• Precautions: Patients undergoing treatment must completely eliminate the contact of family members (especially pregnant women) with crushed medication.

Due to the pronounced estrogenic activity of fosfestrol, Honvan therapy can induce a range of characteristic systemic side effects:

• 🟢 Endocrine Disorders (Very Common): Gynecomastia (swelling and tenderness of the mammary glands), decreased libido, impotence, testicular atrophy, hot flashes.
• 🟡 Cardiovascular System: Fluid retention and peripheral edema, increased blood pressure, thrombophlebitis, increased risk of thromboembolism.
• 🟡 Gastrointestinal System: Nausea, vomiting (especially at the beginning of the course), anorexia, transient liver function abnormalities, cholestatic jaundice.
• 🟠 Neurological Manifestations: Headache, dizziness, increased fatigue, emotional lability, or depressive states.
• ⚠️ Urgent Medical Attention: Upon appearance of signs of thrombosis (acute pain or swelling in the calf muscle, sudden dyspnea, chest pain), the medication must be discontinued and emergency services called immediately.

Ingestion of the medication in doses significantly exceeding the recommended therapeutic schedules results in the manifestation of systemic toxicity:

• Main Manifestations: Acute overdose presents with uncontrollable nausea, vomiting, sharp fluid retention with the development of generalized edema, and a critical spike in blood pressure.
• First Aid: Immediate discontinuation of tablet intake, gastric lavage (if shortly after ingestion), and administration of activated charcoal.
• Treatment: No specific antidote exists. Symptomatic therapy aimed at supporting cardiovascular activity, forced diuresis to eliminate fluid, and monitoring liver function is carried out.

Proper storage of blisters ensures the stability of the chemical structure of fosfestrol throughout its entire shelf life:

• 🌡️ Temperature Regimen: Store in the original factory packaging in a dry, light-protected place at a temperature not exceeding 25°C.
• 📦 Moisture Protection: Prevent damage to blisters; tablets should be extracted immediately before ingestion. Avoid storage in humid rooms.
• 👶 Safety: Store in a secure location out of reach of children and pets. Given the cytostatic nature of the drug, disposal of residues is performed strictly according to medical waste regulations.
• ⏳ Shelf Life: Taking tablets after the expiration date indicated by the manufacturer Zydus on the cardboard box and blister is categorically forbidden.