Tamsulosin-OBL, 0.4 mg 30 pcs

Tamsulosin selectively and competitively blocks postsynaptic alpha1A-adrenoreceptors located in the smooth muscles of the prostate, bladder neck and prostatic part of the urethra as well as alpha1D-adrenoreceptors mainly located in the bladder body.

This leads to decrease of tone of smooth muscles of the prostate, bladder neck and prostatic part of the urethra, improves urine outflow, decreases symptoms of obstruction and irritation of urinary tract in benign prostatic hyperplasia.

The ability of tamsulosin to affect alpha1A-adrenoreceptors is 20 times greater than its ability to interact with alpha1A-adrenoreceptors located in vascular smooth muscle.

Owing to this high selectivity, the drug does not cause any clinically significant systemic decrease in arterial pressure (BP) both in patients with arterial hypertension and in patients with normal baseline BP. As a rule, therapeutic effect is achieved 2 weeks after initiation of the drug.

Pharmacokinetics

Tamsulosin is well absorbed in the intestine and has almost 100% bioavailability. Absorption of tamsulosin slows down slightly after meals. The same level of absorption can be achieved if the patient takes the drug after the usual breakfast each time. Tamsulosin is characterized by linear kinetics.

After a single oral administration of 0.4 mg of the drug, its maximum plasma concentration (Cmax) is reached after 6 hours. After repeated oral intake of 0.4 mg per day the equilibrium concentration (Csс) is reached by the 5th day, and its value is about 2/3 higher than the value of this parameter after a single dose.

The binding to plasma proteins is 99%, the volume of distribution is small (about 0.2 l/kg).

Tamsulosin is slowly metabolized in the liver to form less active metabolites. Most of tamsulosin is present in plasma in unchanged form.

In the experiment the ability of tamsulosin to slightly induce the activity of microsomal liver enzymes was revealed. In mild to moderate hepatic insufficiency there is no need to adjust the dosing regimen.

Tamsulosin and its metabolites are mainly excreted in the urine, with approximately 9% of the drug excreted unchanged.

The elimination half-life (T½) of the drug is 10 hours with a single dose of 0.4 mg after a meal, and 13 hours with multiple doses. There is no need to decrease the dose in renal failure, but in patients with severe renal insufficiency (creatinine clearance (CK) less than 10 ml/min) tamsulosin administration should be used with caution.

Indications

Treatment of functional symptoms of benign prostatic hyperplasia (BPH).

Active ingredient

Composition

1 modified-release capsule contains:

the active substances:

tamsulosin hydrochloride 0.400 mg, in terms of tamsulosin 0.367 mg;

excipients:

Microcrystalline cellulose (101),

Methacrylic acid and ethyl acrylate copolymer (1:1),

triethylcitrate,

talc,

water,

sodium hydroxide/hydrochloric acid.

How to take, the dosage

Tamsulosin is taken orally, 1 capsule (0.4 mg) at the same time after meals once a day.

The capsule should be swallowed whole, sitting or standing, without chewing or crushing, as this may interfere with the gradual release of the active ingredient.

Interaction

No interaction has been observed when concomitant use of tamsulosin with atenolol, enalapril, nifedipine or theophylline. When concomitant use with cimetidine, plasma concentrations of tamsulosin are increased, and when concomitant use of tamsulosin with furosemide is decreased.

However, no dose adjustment is required, since tamsulosin concentrations remain in the therapeutic range.
In vitro diazepam, propranolol, trichloromethiazide, chlormadinone, amitriptyline, diclofenac, glibenclamide, simvastatin and warfarin do not change the level of free fraction of tamsulosin in plasma. In turn, tamsulosin does not change the plasma levels of free fractions of diazepam, propranolol, trichloromethiazide and chlormadinone.

The interaction of tamsulosin with amitriptyline, salbutamol, glibenclamide and finasteride in in vitro studies was not revealed. Simultaneous use of diclofenac or warfarin with tamsulosin may increase the elimination rate of tamsulosin.

Concomitant administration of tamsulosin with drugs that reduce blood pressure, including other alpha1 -adrenoblockers and anesthetics, may increase the hypotensive effect.

Special Instructions

At the first signs of orthostatic hypotension (dizziness, weakness), one should sit or lie down until these symptoms disappear.
Before treatment with tamsulosin, the patient should be examined to exclude other diseases that may cause the same symptoms as benign prostatic hyperplasia.

Before treatment with the drug and during therapy, regular examination of the prostate gland and, if necessary, determination of prostate specific antigen (PSA) should be performed. Due to the possibility of complications during surgical treatment of cataract, it is not recommended to prescribe tamsulosin treatment to patients with cataracts if surgery is planned.

Drowsiness, visual impairment, dizziness and fainting may occur while taking tamsulosin; therefore, the drug should be used with caution while driving vehicles and people whose profession requires increased concentration.

Impact on driving and operating machinery

At the time of treatment, one must refrain from engaging in potentially dangerous activities requiring increased concentration and quick psychomotor reactions.

Contraindications

With caution:
Severe renal insufficiency (decreased creatinine clearance below 10 ml/min).

Side effects

Frequency of adverse reactions: frequently (>1%, 0.1%, 0 01% Nervous system disorders: frequently – dizziness, infrequently – headache, rarely – fainting; sleep disorders (drowsiness or insomnia);

Cardiovascular system disorders: infrequent – tachycardia, orthostatic hypotension; pain in the chest;

Respiratory system: infrequent – rhinitis.

Digestive system: infrequent – constipation, diarrhea, nausea, vomiting.

Skin and skin: infrequent – rash, itching, urticaria; rarely – angioedema.

Urogenital system: infrequent – retrograde ejaculation, very rare – priapism; decreased libido;

Others: sometimes – asthenia, back pain, small pupil syndrome during cataract surgery.

Overdose

The cases of overdose have not been described, in theory, acute hypotension is possible.

Treatment: in case of overdose it is recommended to put the patient in horizontal position and to perform measures aimed at maintaining cardiovascular function (restoration of blood pressure and heart rate); gastric lavage, administration of activated charcoal and osmotic laxatives such as sodium sulfate.

If there is no effect, a circulating blood volume booster and, if necessary, vasoconstrictors should be given.

Renal function should be monitored and measures taken to maintain it. Dialysis is of little use in tamsulosin overdose because the drug is largely bound to plasma proteins.

Similarities