HARNAL OCAS Tamsulosin Hydrochloride 400mcg Prolonged Release Film-Coated Tablet 1's
Indications/Uses
For the medical management of ureteral stones (stones less than 1 cm in diameter) and for post clearance extracorporeal shock wave lithotripsy (ESWL).
Dosage/Direction for Use
Can be taken independently of food.
The tablet must be swallowed whole and not be crunched or chewed as this interferes with the prolonged release of the active substance.
No dose adjustment is warranted in renal impairment.
No dose adjustment is warranted in patients with mild to moderate hepatic insufficiency.
There is no relevant indication for use of Harnal OCAS 400 mcg Film-coated Tablet in children.
Overdosage
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.
Administration
Contraindications
Special Precautions
Safety in female patients has not been established. In patient with ureteral stones, this drug should be used in male patients only.
Before therapy with Harnal OCAS 400 mcg Film-coated Tablet is initiated, the patient should be examined in order to exclude the presence of other conditions, which can cause the same symptoms as benign prostatic hyperplasia. Digital rectal examination and, when necessary, determination of prostate specific antigen (PSA) should be performed before treatment and at regular intervals afterwards.
Treatment of patients with a history of orthostatic hypotension should be approached with caution.
The treatment of patients with severe renal impairment (creatinine clearance of <10mL/min) should be approached with caution, as these patients have not been studied.
The treatment of patients with severe hepatic dysfunction should be approached with caution.
Intraoperative Floppy Iris Syndrome (IFIS, a variant of small pupil syndrome) considered to be due to alpha-1 blocking action has been observed during cataract and glaucoma surgery in some patients on or previously treated with tamsulosin. Ophthalmologists should be aware of possible occurrence of IFIS during the surgery.
Harnal OCAS 400 mcg Film-coated Tablet should be used with caution in combination with strong inhibitors of CYP3A4 (see Pharmacology: Pharmacokinetics under Actions and Interactions). Harnal OCAS 400 mcg Film-coated Tablet should not be used in combination with strong inhibitors of CYP3A4 in patients known to be CYP2D6 poor metabolizers.
Cases of allergic reaction to tamsulosin in patients with a past history of sulfonamide allergy have been reported. If a patient reports a previously experienced sulfa allergy, caution is warranted when administrating tamsulosin hydrochloride.
Concurrent administration of other α1-adrenoceptor antagonists could lead to hypotension effects.
Effects on Ability to Drive and Use of Machines: No studies on the effects on the ability to drive and use machines have been performed. However, patients should be aware of the fact that dizziness can occur.
Use In Pregnancy & Lactation
Adverse Reactions
During cataract and glaucoma surgery a small pupil situation, known as Intraoperative Floppy Iris Syndrome (IFIS), has been reported during post-marketing surveillance (see Precautions).
Drug Interactions
Concomitant cimetidine brings about a rise in plasma levels of tamsulosin, while furosemide a fall, but as levels remain within the normal range posology need not be adjusted.
In vitro, neither diazepam nor propanolol, trichlormethiazide, chlormadinone, amitriptyline, diclofenac, glibenclamide, simvastatin and warfarin change the free fraction of tamsulosin in human plasma. Neither does tamsulosin change the free fractions of diazepam, propanolol, trichlormethiazide and chlormadinone. Diclofenac and warfarin, however, may increase the elimination rate of tamsulosin.
PK studies in healthy volunteers revealed that concomitant administration with strong inhibitors of CYP3A4 or CYP2D6 may lead to increased exposure to tamsulosin. Concomitant administration with ketoconazole (a known CYP3A4 inhibitor) resulted in a Cmax and AUC of tamsulosin that had increased by a factor of 2.2 and 2.8, respectively. Concomitant administration with paroxetine (a known CYP2D6 inhibitor) resulted in a Cmax and AUC of tamsulosin that had increased by a factor of 1.3 and 1.6, respectively (see Precautions).
Concurrent administration of other α1-adrenoceptor antagonists could lead to hypotension effects.
Storage
Action
Pharmacology: Pharmacodynamics: Mechanism of action: Tamsulosin 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 effects: Harnal OCAS 400 mcg Film-coated Tablet 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. The need for surgery or catheterization is significantly delayed.
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 Harnal OCAS 400 mcg Film-coated Tablet.
Pharmacokinetics: Absorption: Harnal OCAS 400 mcg Film-coated Tablet is a prolonged release tablet of the non-ionic gel matrix type. The OCAS (Oral Controlled Absorption System) formulation provides consistent slow release of tamsulosin, resulting in an adequate exposure, with little fluctuation, over 24 hours.
Tamsulosin administered as Harnal OCAS 400 mcg Film-coated Tablet is absorbed from the intestine. Under fasting conditions of the administered dose, approximately 57% is estimated to be absorbed.
The rate and extent of absorption of tamsulosin administered as Harnal OCAS 400 mcg Film-coated Tablet are not affected by a low-fat meal. The extent of absorption is increased by 64% and 149% (AUC and Cmax respectively) by a high-fat meal compared to fasted.
Tamsulosin shows linear pharmacokinetics.
After single dose of Harnal OCAS 400 mcg Film-coated Tablet 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 Harnal OCAS 400 mcg Film-coated Tablet 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.
Distribution: In man, tamsulosin is about 99% bound to plasma proteins. The volume of distribution is small (about 0.2L/kg).
Metabolism: Tamsulosin has a low first pass effect, being metabolized slowly. Most tamsulosin is present in plasma in the form of unchanged active substance. It is metabolized in the liver.
In rats, hardly any induction of microsomal liver enzymes was seen to be caused by tamsulosin.
In vitro results suggest that CYP3A4 and also CYP2D6 are involved in metabolism, with possible minor contributions to tamsulosin metabolism by other CYP isozymes. Inhibition of hepatic drug metabolizing enzymes may lead to increased exposure to tamsulosin (see Precautions and Interactions).
None of the metabolites is more active than the original compound.
Excretion: Tamsulosin 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 Harnal OCAS 400 mcg Film-coated Tablet.
After single dose of Harnal OCAS 400 mcg Film-coated Tablet and in steady state, elimination half-lives of about 19 and 15 hours, respectively, have been measured.
Toxicology: Pre-Clinical Safety Data: Single and repeat dose toxicity studies were performed in mice, rats and dogs. In addition, reproduction toxicity in rats, carcinogenicity in mice and rats and in vivo and in vitro genotoxicity were examined.
The general toxicity profile, as seen with high doses of tamsulosin, is inconsistent with the known pharmacological actions of the α1-adrenoceptor antagonists.
At very high dose levels, the ECG was altered in dogs. This response is considered to be not clinically relevant. Tamsulosin showed no relevant genotoxic properties.
Increased incidences of proliferative changes of mammary glands of female rats and mice have been reported. These findings, which are probably mediated by hyperprolactinemia and only occurred at high dose levels, are regarded as irrelevant.
MedsGo Class
Features
- Tamsulosin