Tamsulosin selectively and competitively blocks postsynaptic adrenoceptors in the smooth muscle of the prostate, bladder neck and prostatic urethra and fluoxymesterone receptors located predominantly in the body of the bladder. This leads to a reduction in smooth muscle tone of the prostate, bladder neck, prostatic urethra, enhances the flow of urine, reduces urinary tract symptoms of irritation and obstruction in benign prostatic hyperplasia.
The ability to influence the tamsulosin greater than its ability to interact with alfa1A -adrenoceptors located in vascular smooth muscle. Due to such high selectivity, the drug does not cause any clinically significant decrease in systemic blood pressure both in hypertensive patients and in patients with normal blood pressure source. Typically, the therapeutic effect is achieved within 2 weeks after starting treatment.
After oral administration of tamsulosin is rapidly and almost completely absorbed from the gastrointestinal tract. The bioavailability of the drug – about 100%. After a single dose of the drug inside the Cmax of the active substance in plasma is reached after 6 hours.
Immediately after ingestion decreases the absorption of tamsulosin. The uniformity of the suction increases when the patient takes medication every fluoxymesterone day after the same meal.
In the equilibrium state value of the active substance in plasma at 60-70% higher than the Cmax after a single dose.
Binding to plasma proteins – 99%. Tamsulosin has a slight volume of distribution (approximately 0.2 l / kg).
Tamsulosin little exposed to the effect of “first pass” and slowly biotransformed in the liver to produce less pharmacologically active metabolites that retain high selectivity for alpha 1-adrenoceptor Most of the active substance is present in the blood in an unmodified form. When liver failure dose adjustment is required.
Tamsulosin and its metabolites are primarily excreted by the kidneys, with approximately 9% staff excreted unchanged. T1 / 2 at a single dose of tamsulosin – 10 hours after multiple dose – 13 hours a finite half-life -. 22 hours Correction dose of tamsulosin in the presence of kidney disease is not required.
Treatment of the functional symptoms of benign prostatic hyperplasia (BPH).
- Hypersensitivity to tamsulosin hydrochloride or the other ingredients;
- Orthostatic hypotension (including history);
- Severe hepatic insufficiency.
Severe renal impairment (creatinine clearance less than 10 mL / min).
Dosage and administration
Inside, the capsule 1 (0.4 mg) in fluoxymesterone the same time after meals once daily. Capsule must be swallowed whole, sitting or standing, not gnawing or chewing, as this can disrupt the gradual release of the active ingredient.
From the nervous system: often – dizziness, rarely – headache, rare – fainting; sleep disturbance (insomnia or drowsiness), Cardio-vascular system: rarely – tachycardia, orthostatic hypotension; chest pain; the part of the respiratory system: rarely – rhinitis. From the digestive system: rarely – constipation, diarrhea, nausea, vomiting. Skin and Skin: rare – rash, pruritus, urticaria; rarely – angioedema. From the urogenital system: rarely – retrograde ejaculation, very rarely – priapism;decreased libido; Other: sometimes – asthenia, back pain, small pupil syndrome, during cataract surgery
Interaction with other drugs
There was no interaction while taking tamsulosin with atenolol, enalapril, nifedipine or theophylline. When concomitantly with cimetidine tamsulosin plasma concentration increased, and at the same time taking tamsulosin with furosemide – reduced. However, a dose adjustment is required, because the concentration of tamsulosin remains within the therapeutic range.
In vitro diazepam, propranolol, trichloromethiazide, chlormadinone, amitriptyline, diclofenac, glibenclamide, simvastatin and warfarin did not change the level of the free fraction of tamsulosin in plasma. In turn, does not change the content of fluoxymesterone tamsulosin free fractions of diazepam, propranolol, trichlormethiazide and chlormadinone in plasma.