- tamsulosin hydrochloride
POM: Prescription only medicine
This information is intended for use by health professionals
PosologyOne tablet daily. Tamsulosin can be taken independently of food.
Renal impairmentNo dose adjustment is warranted in renal impairment.
Hepatic impairmentNo dose adjustment is warranted in patients with mild to moderate hepatic insufficiency (see also 4.3, Contraindications).
Paediatric populationThe safety and efficacy of tamsulosin in children and adolescents have not been established. Currently available data are described in section 5.1.There is no relevant indication for use of tamsulosin in children.
Method of administrationOral use.The tablet must be swallowed whole and not be crunched or chewed as this interferes with the prolonged release of the active substance.
|MedDRA system organ class||Common (≥1/100 to <1/10)||Uncommon (≥1/1,000 to <1/100)||Rare (≥1/10,000 to <1/1,000)||Very rare (<1/10,000)||Not known (cannot be estimated from the available data)|
|Nervous systems disorders||Dizziness (1.3%)||Headache||Syncope|
|Eye disorders||Vision blurred, visual impairment|
|Vascular disorders||Orthostatic hypotension|
|Respiratory, thoracic and mediastinal disorders||Rhinitis||Epistaxis|
|Gastro-intestinal disorders||Constipation, diarrhoea, nausea, vomiting||Dry mouth|
|Skin and subcutaneous tissue disorders||Rash, pruritus, urticaria||Angioedema||Stevens-Johnson syndrome||Erythema multiforme, dermatitis exfoliative|
|Reproductive system and breast disorders||Ejaculation disorders, retrograde ejaculation, ejaculation failure||Priapism|
|General disorders and administration site conditions||Asthenia|
Reporting of suspected adverse reactionsReporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme, Website: www.mhra.gov.uk/yellowcard.
SymptomsOverdosage with tamsulosin can potentially result in severe hypotensive effects. Severe hypotensive effects have been observed at different levels of overdosing.
TreatmentIn case of acute hypotension occurring after overdosage cardiovascular support should be given. Blood pressure can be restored and heart rate brought back to normal by lying the patient down. If this does not help then volume expanders and, when necessary, vasopressors could be employed. Renal function should be monitored and general supportive measures applied. Dialysis is unlikely to be of help as tamsulosin is very highly bound to plasma proteins. Measures, such as emesis, can be taken to impede absorption. When large quantities are involved, gastric lavage can be applied and activated charcoal and an osmotic laxative, such as sodium sulphate, can be administered.
Mechanism of actionTamsulosin binds selectively and competitively to the postsynaptic α1-adrenoceptors, in particular to subtypes α1A and α1D. It brings about relaxation of prostatic and urethral smooth muscle.
Pharmacodynamic effectsTamsulosin increases the maximum urinary flow rate. It relieves obstruction by relaxing smooth muscle in prostate and urethra thereby improving voiding symptoms. It also improves the storage symptoms in which bladder instability plays an important role. These effects on storage and voiding symptoms are maintained during long-term therapy. Observational data indicate that use of tamsulosin may lead to a delay in the need for surgery or catheterization. α1-adrenoceptor antagonists can reduce blood pressure by lowering peripheral resistance. No reduction in blood pressure of any clinical significance was observed during studies with tamsulosin.
Paediatric populationA double-blind, randomized, placebo-controlled, dose ranging study was performed in children with neuropathic bladder. A total of 161 children were randomized and treated at 1 of 3 dose levels of tamsulosin (low [0.001 to 0.002 mg/kg], medium [0.002 to 0.004 mg/kg], and high [0.004 to 0.008 mg/kg]), or placebo. A response was defined as a primary endpoint with patients who decrease their detrusor leak point pressure (LPP) to <40 cm H2O based upon two evaluations on the same day. Secondary endpoint were: Actual and percent change from baseline in detrusor leak point pressure, improvement or stabilization of hydronephrosis and hydroureter and change in urine volumes obtained by catheterisation and number of times wet at time of catheterisation as recorded in catheterisation diaries. No statistically significant differences were found between the placebo group and any of the 3 tamsulosin dose groups for either the primary or any secondary endpoint. Additional exploratory analyses in subgroups confirmed these findings (e.g. age, anti-cholinergic use, weight, geographic regions). No dose response was observed for any dose level.
AbsorptionThe Tamsulosin prolonged-release formulation provides consistent slow release of tamsulosin, resulting in an adequate exposure, with little fluctuation, over 24 hours. Tamsulosin administered as Tamsulosin prolonged-release tablets is absorbed from the intestine. Of the administered dose, approximately 57% is estimated to be absorbed. The rate and extent of absorption of tamsulosin administered as Tamsulosin hydrochloride prolonged release tablets are not affected by food. Tamsulosin shows linear pharmacokinetics. After a single dose of tamsulosin in the fasted state, plasma concentrations of tamsulosin peak at a median time of 6 hours. In steady state, which is reached by day 4 of multiple dosing, plasma concentrations of tamsulosin peak at 4 to 6 hours, in the fasted and fed state. Peak plasma concentrations increase from approximately 6 ng/ml after the first dose to 11 ng/ml in steady state. As a result of the prolonged-release characteristics of Tamsulosin prolonged-release tablets the trough concentration of tamsulosin in plasma amounts to 40% of the peak plasma concentration under fasted and fed conditions. There is a considerable inter-patient variation in plasma levels both after single and multiple dosing.
DistributionIn man, tamsulosin is about 99% bound to plasma proteins. The volume of distribution is small (about 0.2 l/kg).
BiotransformationTamsulosin has a low first pass effect, being metabolised slowly. Most tamsulosin is present in plasma in the form of unchanged active substance. It is metabolised in the liver. In rats, hardly any induction of microsomal liver enzymes was seen to be caused by tamsulosin. None of the metabolites are more active than the original compound.
EliminationTamsulosin and its metabolites are mainly excreted in the urine. The amount excreted as unchanged active substance is estimated to be about 4 - 6% of the dose, administered as Tamsulosin prolonged-release tablets.After a single dose of tamsulosin and in steady state, elimination half-lives of about 19 and 15 hours, respectively, have been measured.
Inner core tablet:HypromelloseCellulose microcrystallineCarbomerSilica colloidal anhydrousIron oxide red (E172)Magnesium stearate
Outer tablet:Cellulose microcrystallineHypromelloseCarbomerSilica colloidal anhydrousMagnesium stearate