Tamsulosin binds selectively and competitively to postsynaptic? 1A adrenoreceptors, which transmit smooth muscle contraction, resulting in relaxation of the smooth muscle of the prostate and urethra.
Pharmacodynamic effects
Tamsulosin increases the maximum urinary flow by relaxing the smooth musculature of the prostate and urethra, relieving the obstruction.
The drug also improves irritative and obstructive symptoms in which the contraction of the smooth muscles of the lower urinary tract plays an important role.
Blockers can reduce blood pressure by decreasing peripheral resistance. During studies with tamsulosin, no clinically significant reduction in blood pressure was observed in normotensive patients.
These effects on filling and emptying symptoms are maintained during long-term treatment. The need for surgical treatment or catheterization is significantly delayed.
Always use this medicine exactly as your doctor has told you. If in doubt, consult your doctor or pharmacist again.
The recommended dose is one capsule a day after breakfast.
The capsule should be taken standing or sitting upright (not lying down) and swallowed whole with a glass of water. The capsule must not be chewed.
Your doctor has prescribed a suitable dose for you and your illness and has specified the duration of your treatment.
You should not change the dose by yourself.
If you think the action of Flomax is too strong or weak, tell your doctor or pharmacist.
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Stop taking Flomax and see your doctor immediately if you experience the following:
- sudden inflammation of any or all of the following parts: hands, feet, lips, tongue or throat causing difficulty in breathing and/or itching and rash, caused by an allergic reaction (angioedema),
- severe ulcers and lesions on the mucous membranes (Steven-Johnson syndrome),
- severe inflammation and blisters on the skin known as erythema multiforme.
Common (may affect up to 1 in 10 patients):
dizziness, ejaculation disorders including minor or undetectable ejaculation of semen.
Uncommon (may affect up to 1 in 100 patients):
headache, irregular heartbeat, dizziness especially when sitting or getting up, colds, constipation, diarrhea, nausea, vomiting, rash, itching, hives, feeling weak.
Rare (may affect up to 1 in 1,000 patients):
fainting, swelling of the hands or feet, swelling of the lips, tongue or throat causing difficulty in breathing and/or itching and rash (angioedema).
Very rare (may affect up to 1 in 10,000 patients):
severe ulcers and lesions on the mucous membranes (Stevens-Johnson syndrome), painful and persistent erection in the absence of sexual arousal (priapism).
Frequency not known (frequency cannot be estimated from the available data):
blurred vision, visual dysfunction, bleeding from the nose, severe inflammation and blisters on the skin (erythema multiforme), peeling of the skin (exfoliative dermatitis), irregular heart rhythm (sometimes life-threatening), rapid heart rate, difficulty breathe, dry mouth. If you are going to have an eye surgery due to a clouding of the lens (cataracts) or an increase in pressure in the eye (glaucoma), and you are already taking or have previously taken Flomax (tamsulosin), the pupil may be dilated very little and the iris (colored circular part of the eye) may become flabby during the operation.
warnings and precautions
As with other α1-adrenergic receptor antagonists, in individual cases, a decrease in blood pressure may occur during treatment with Flomax (tamsulosin), which, rarely, may produce syncope. At the first symptoms of orthostatic hypotension (dizziness, weakness), the patient should sit or lie down until the symptoms have disappeared.
Concomitant use of 5-phosphodiesterase inhibitors (eg, sildenafil, tadalafil, vardenafil) and Flomax (tamsulosin) may cause symptomatic hypotension in certain patients. In order to minimize the risk of developing postural hypotension, the patient should have been stabilized with alpha-blocking treatment before starting treatment with 5-phosphodiesterase inhibitors.
Before starting treatment with Flomax (tamsulosin), the patient should be examined to rule out the presence of other pathologies that may cause the same symptoms as benign prostatic hyperplasia. Before treatment and afterward, at regular intervals, the examination should be performed by digital rectal examination, and if necessary, the determination of the prostate-specific antigen (PSA).
Treatment of patients with severe renal impairment (creatinine clearance less than 10 ml/min) should be approached with caution, as these patients have not been studied.
