Sonisin, 0.4 mg 30 pcs

Sonisin is an alpha1-adrenoblocker

Pharmacodynamics

Tamsulosin selectively and competitively blocks postsynaptic α_1A-adrenoreceptors located in the smooth muscle of the prostate, bladder neck and prostatic part of the urethra, as well as α_1D-adrenoreceptors mainly located in the bladder body.

This leads to reduction of tone of the smooth muscles of the prostate, bladder neck and prostatic part of the urethra and improvement of detrusor function.

This decreases symptoms of obstruction and irritation associated with benign prostatic hyperplasia. As a rule, the therapeutic effect develops 2 weeks after the start of therapy, although some patients have less symptoms after the first dose.

The ability of tamsulosin to affect α_1A adrenoreceptors is 20 times greater than its ability to interact with α_1B adrenoreceptors located in vascular smooth muscle.

This high selectivity ensures that the drug does not cause any clinically significant reduction in systemic arterial blood pressure (BP) in both patients with arterial hypertension and patients with normal baseline BP.

Pharmacokinetics

Intake

After oral administration, tamsulosin is rapidly and almost completely absorbed from the gastrointestinal tract. The bioavailability of the drug is about 100%.

After a single oral dose of 400 mcg the Cmax of the active substance in plasma is reached after 6 hours.

Distribution
At equilibrium (after 5 days of a course of administration) the C_max values of the active substance in plasma are 60-70% higher than C_max after a single dose of the drug.

The binding to plasma proteins is 99%. Tamsulosin has a low volume of distribution (approximately 0.2 L/kg).

Metabolism

Tamsulosin does not undergo a “first pass” effect and is slowly biotransformed in the liver to form pharmacologically active metabolites that remain highly selective to α_1A-adrenoreceptors. Most of the active substance is present in the blood unchanged.

Elimination
Tamsulosin is excreted by the kidneys, 9% of the dose is excreted unchanged.

The T1/2 of tamsulosin in single administration is 10 hours, after multiple administration – 13 hours, the final elimination half-life is 22 hours.

Indications

Treatment of dysuric disorders due to benign prostatic hyperplasia.

Active ingredient

How to take, the dosage

Orally, after meals, 1 capsule of Sonisin per day, at the same time of day, with enough water.

The capsule should neither be crushed into pieces nor chewed because this would interfere with the prolonged release of the active ingredient.

Interaction

Cimetidine increases the plasma concentration of tamsulosin, furosemide decreases it (no significant clinical significance, no dosage changes are required).

Diclofenac and indirect anticoagulants increase tamsulosin excretion.

Diazepam, propranololol, trichloromethiazide, chlormadinone, amitriptyline, diclofenac, glibenclamide, simvastatin and warfarin do not alter the free fraction of tamsulosin in human plasma in vitro. In turn, tamsulosin does not alter the free fractions of diazepam, propranolol, trichloromethiazide and chlormadinone.

In in vitro studies, no hepatic metabolic interactions have been found with amitriptyline, salbutamol, glibenclamide and finasteride.

Other alpha 1-adreno-blockers, acetylcholinesterase inhibitors, alprostadil, anesthetics, diuretics, levodopa, antidepressants, beta-adreno-blockers, slow calcium channel blockers, nitrates and ethanol may increase the severity of hypotensive effect of tamsulosin.

Special Instructions

Like other α1-adrenoblockers, tamsulosin may cause a decrease in BP, rarely causing fainting. At the first signs of orthostatic hypotension (dizziness, weakness) it is necessary to sit or lay the patient down until the symptoms disappear.

Tamsulosin treatment should be preceded by a preliminary evaluation of the patient to rule out any other disease presenting with the same symptoms as benign prostatic hyperplasia. Pre-treatment must be preceded by a preliminary rectal palpate examination of the prostate and measurement of prostate specific antigen (PSA) levels, which are routinely repeated later in the course of treatment.

At the time of treatment, you should refrain from engaging in potentially hazardous activities that require increased concentration and quick psychomotor reactions.

Contraindications

Hypersensitivity to tamsulosin hydrochloride or any other component of the drug Sonisin.

With caution: chronic renal failure (decreased creatinine clearance below 10 ml/min), arterial hypotension (including orthostatic), severe hepatic insufficiency.

Side effects

Rarely – headache, dizziness, asthenia, sleep disorders (somnolence or insomnia), retrograde ejaculation, decreased libido, back pain, rhinitis; in single cases – orthostatic hypotension, tachycardia, palpitation, chest pain.

Digestive system disorders: in rare cases – nausea, vomiting, constipation or diarrhea. In extremely rare cases of hypersensitivity reactions – skin rash, itching, angioedema.

Overdose

In cases of acute overdose have not been described.

Symptoms: acute hypotension and compensatory tachycardia are theoretically possible.

Treatment: patient should be laid down to restore blood pressure and normalize heart rate. Cardiotropic therapy is given. Renal function should be monitored and general supportive therapy should be used.

If symptoms persist, volumetric replacement solutions and vasoconstrictors should be administered.

In order to prevent further absorption of tamsulosin, gastric lavage, administration of activated charcoal or osmotic laxatives are possible.

Dialysis is not effective because tamsulosin is firmly bound to plasma proteins.

Similarities