Prostazan-vista

INSTRUCTIONS FOR MEDICAL USE OF THE MEDICINAL PRODUCT PROSTAZAN-VISTA (PROSTAZAN-VISTA)

Composition:

Active substance: tamsulosin hydrochloride;

One prolonged-release tablet contains 0.4 mg of tamsulosin hydrochloride;

Excipients: hypromellose, microcrystalline cellulose, carbomer, colloidal anhydrous silicon dioxide, iron oxide red (E 172), magnesium stearate.

Pharmaceutical form. Prolonged-release tablets.

Main physicochemical properties: white, round tablets without a break line, with embossing «T9SL» on one side and «0.4» on the other side.

Pharmacotherapeutic group. Agents used in benign prostatic hyperplasia. α1-adrenergic receptor antagonists. ATC code G04C A02.

Pharmacological Properties

Pharmacodynamics

Tamsulosin hydrochloride selectively and competitively blocks postsynaptic α1-adrenoceptors, particularly α1A and α1D subtypes, located in the smooth muscle of the prostate gland, bladder neck, and prostatic urethra. This leads to reduced smooth muscle tone in the prostate, bladder neck, and prostatic urethra, thereby improving urinary flow. Simultaneously, symptoms of obstruction and irritation associated with benign prostatic hyperplasia (difficulty initiating urination, weakened urinary stream, dribbling after urination, sensation of incomplete bladder emptying, frequent urges to urinate, nocturia, urgency) are alleviated.

The ability of α1A-adrenergic blockers to reduce arterial pressure is related to decreased peripheral resistance. Prostasan-Vista at a daily dose of 0.4 mg does not cause clinically significant reduction in systemic arterial pressure (AP) in patients with arterial hypertension or in patients with normal baseline arterial pressure.

Pharmacokinetics

Absorption. Prostasan-Vista is a prolonged-release tablet that ensures sustained and gradual release of tamsulosin, providing exposure with minimal fluctuations over 24 hours. After oral administration on an empty stomach, 57% of tamsulosin is absorbed in the intestine.

The rate and extent of absorption of the prolonged-release tablets are not altered when taken with a low-fat meal. However, the extent of absorption increases by 64% and 149% (area under the plasma concentration-time curve (AUC) and maximum plasma concentration (Cmax), respectively) when taken with a high-fat meal compared to administration on an empty stomach.

Tamsulosin exhibits linear pharmacokinetics.

After a single dose of Prostasan-Vista taken on an empty stomach, the Cmax of the active substance is reached at 6 hours. At steady state, achieved by the 4th day of tamsulosin administration, Cmax occurs within 4–6 hours regardless of food intake. Peak plasma concentration increases from approximately 6 ng/mL after the first dose to 11 ng/mL at steady state.

Due to prolonged release, the trough plasma concentration of tamsulosin reaches 40% of Cmax, independent of food intake.

Distribution. Plasma protein binding is 99%. The volume of distribution of tamsulosin is low (approximately 0.2 L/kg).

Metabolism. Tamsulosin hydrochloride has low first-pass effect and is slowly metabolized. The majority of the active substance circulates in unchanged form. It is metabolized in the liver. In vitro data indicate that CYP3A4 and also CYP2D6 are involved in its metabolism, while other CYP isoenzymes have minimal influence on tamsulosin. Inhibition of metabolic enzymes CYP3A4 and CYP2D6 may lead to increased exposure to tamsulosin hydrochloride (see sections "Interaction with other medicinal products and other forms of interaction", "Special warnings and precautions for use"). None of the metabolites are more active than the parent compound.

Excretion. Tamsulosin and its metabolites are primarily excreted via the kidneys, with 4–6% of the dose excreted unchanged. The elimination half-life of tamsulosin after single-dose administration and at steady state is 19 and 15 hours, respectively.

Clinical characteristics.

Indications.

Treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia.

Contraindications.

Hypersensitivity to tamsulosin hydrochloride, including drug-induced angioneurotic edema, or to any of the excipients; history of orthostatic hypotension; severe hepatic impairment.

Interaction with other medicinal products and other forms of interaction.

Interaction studies have been conducted only in adults.

No pharmacological interaction was observed when tamsulosin hydrochloride was administered concomitantly with atenolol, enalapril, nifedipine, or theophylline. Concomitant administration with cimetidine increases, while with furosemide decreases, tamsulosin plasma concentration; however, since these levels remain within the normal range, no special dose adjustment of tamsulosin is required.

In vitro studies show that diazepam, propranolol, trichlormethiazide, chloromadinone, amitriptyline, diclofenac, glyburide, simvastatin, and warfarin do not affect the free fraction of tamsulosin in human plasma. Similarly, tamsulosin does not alter the free fraction levels of diazepam, propranolol, trichlormethiazide, and chloromadinone in human plasma.

However, diclofenac and warfarin may increase the elimination rate of tamsulosin. Concomitant use of strong CYP3A4 inhibitors may lead to increased effects of tamsulosin hydrochloride. Co-administration with ketoconazole (a strong CYP3A4 inhibitor) resulted in approximately 2.8-fold and 2.2-fold increases in AUC and Cmax, respectively. Tamsulosin hydrochloride should not be administered in combination with strong CYP3A4 inhibitors to patients who are poor metabolizers of CYP2D6.

Tamsulosin hydrochloride should be used with caution when administered concomitantly with strong or moderate CYP3A4 inhibitors.

Concomitant administration of tamsulosin hydrochloride and paroxetine (a strong CYP2D6 inhibitor) resulted in approximately 1.3-fold and 1.6-fold increases in Cmax and AUC, respectively, but this increase is not considered clinically significant.

Concomitant use with other α1-adrenergic blockers may enhance the hypotensive effect.

Special precautions for use.

As with other α1-adrenoblockers, administration of tamsulosin may in individual cases lead to a decrease in blood pressure, which can suddenly result in loss of consciousness. If the first signs of orthostatic hypotension (dizziness, weakness) occur, the patient should sit down or assume a horizontal position until the aforementioned symptoms disappear.

Before initiating treatment with the medicinal product Prostazan-Vista, a medical examination should be performed to rule out other concomitant diseases that may cause symptoms similar to benign prostatic hyperplasia. Prior to starting therapy, a digital rectal examination of the prostate should be performed, and if necessary, a test to determine the level of prostate-specific antigen (PSA) should be conducted before treatment initiation and at regular intervals during treatment. The drug should be administered with particular caution to patients with severe renal impairment (creatinine clearance < 10 mL/min), as clinical studies have not been conducted in such patients.

In some patients who were taking or had previously taken tamsulosin, intraoperative floppy iris syndrome (IFIS, a variant of miosis syndrome) has been observed during cataract or glaucoma surgery, which may lead to an increased risk of complications during or after such procedures.

Generally, it is recommended to discontinue tamsulosin treatment 1–2 weeks before cataract or glaucoma surgery; however, the benefit of discontinuing tamsulosin has not yet been definitively established. Cases of floppy iris syndrome have also been reported in patients who had discontinued tamsulosin long before cataract surgery. Starting tamsulosin hydrochloride treatment is not recommended in patients scheduled for cataract or glaucoma surgery. Surgeons and ophthalmologists should be informed whether the patient is currently taking (or has previously taken) tamsulosin to prevent possible complications associated with IFIS.

Tamsulosin hydrochloride should not be prescribed in combination with strong CYP3A4 inhibitors to patients who are poor metabolizers of CYP2D6.

Tamsulosin hydrochloride should be used with caution in combination with strong and moderate CYP3A4 inhibitors (see "Interaction with other medicinal products and other forms of interaction").

Occasionally, tablet remnants may be observed in feces.

Allergic reactions to tamsulosin hydrochloride have been reported in patients with a history of allergy to sulfonamides. Caution should be exercised when administering tamsulosin hydrochloride to patients who have previously experienced allergic reactions to sulfonamides.

Use during pregnancy or breastfeeding.

Prostazan-Vista is not indicated for use in women.

Fertility.

During both short-term and long-term clinical studies of tamsulosin, ejaculation disorders were observed. Cases of ejaculation disorders, retrograde ejaculation, and impaired ejaculation have been reported in the post-marketing period.

Ability to influence reaction speed when driving or operating machinery.

Studies on the effect of tamsulosin on the ability to drive or operate machinery have not been conducted. However, patients should be warned about the possible occurrence of drowsiness, blurred vision, dizziness, and fainting.

Method of Administration and Dosage.

The recommended dose is 1 tablet daily, independent of food intake. The tablet should be swallowed whole, without breaking or chewing, as this may interfere with the prolonged and controlled release of the active ingredient. The duration of treatment is determined individually.

Dose adjustment is not required in patients with renal impairment or in patients with mild to moderate hepatic impairment (see section "Contraindications").

Children.

This medicinal product is not recommended for use in children.

The safety and efficacy of tamulosin in children have not been established.

Overdose.

Symptoms. Overdose of tamulosin hydrochloride may cause severe hypotension. Pronounced hypotensive effects have been observed at various levels of overdose. Treatment. In case of a sharp drop in blood pressure due to overdose, supportive therapy aimed at restoring normal cardiovascular function should be administered (e.g., the patient should be placed in a supine position). If this measure is ineffective, infusion therapy should be initiated and vasopressor agents administered. Renal function should be monitored, and general supportive therapy provided. Due to the high degree of plasma protein binding of tamulosin, hemodialysis is unlikely to be effective.

To prevent further absorption of tamulosin, induced vomiting may be considered. In cases of significant overdose, gastric lavage with activated charcoal and low-osmotic laxatives such as sodium sulfate should be performed.

Adverse reactions.

All adverse reactions are listed by organ systems and frequency: very common (≥ 1/10), common (≥ 1/100 – < 1/10), uncommon (≥ 1/1000 – < 1/100), rare (≥ 1/10000 – < 1/1000), very rare (< 1/10000), frequency not known (cannot be estimated from the available data).

* Reported during the post-marketing period.

Post-marketing experience: Cases of intraoperative iris floppy-iris syndrome (intraoperative floppy-iris syndrome, IFIS) during cataract and glaucoma surgery have been reported in patients receiving tamsulosin (see section "Dosage and administration"). In addition to the above-mentioned adverse reactions, cases of atrial fibrillation, arrhythmia, tachycardia, and dyspnea have been reported. As with other alpha-blockers, somnolence, dry mouth, and edema may occur. The reported adverse reactions were notified spontaneously; therefore, the frequency and the role of tamsulosin in these cases cannot be reliably determined.

Reporting of suspected adverse reactions.

Reporting suspected adverse reactions after medicine authorization is of great importance. It allows continuous monitoring of the benefit-risk balance of the medicine. Healthcare professionals and patients or their legal representatives should report all suspected adverse reactions and lack of efficacy via the Automated Pharmacovigilance Information System at the following link: https://aisf.dec.gov.ua

Shelf life. 3 years.

Storage conditions. Store in the original packaging at a temperature not exceeding 25 °C. Keep out of reach of children.

Packaging. 10 tablets per blister, 3 blisters per cardboard box.

Prescription status. Prescription only.

Manufacturer.

Sintrop Spain, S.L.

Manufacturer's address and place of business.

C/Castello, no1, Sant Boi de Llobregat, Barcelona, 08830, Spain.