Alpha1-Adrenoceptor Antagonist

Tamsulosin Hydrochloride

Each tablet contains as active ingredient tamsulosin hydrochloride 400 micrograms, equivalent to 367 micrograms tamsulosin.

Film coated, prolonged release tablet. Approximately 9 mm, round, bi-convex, yellow, film-coated tablets debossed with the code '04'.

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

Posology

One tablet daily, to be taken with or without food.

Method of administration

For oral use.

The tablet should be swallowed whole and should not be crunched or chewed as this will interfere with the prolonged release of the active ingredient.

A history of orthostatic hypotension; severe hepatic insufficiency.

Hypersensitivity to tamsulosin hydrochloride or any other component of the product.

As with other alpha₁ blockers, a reduction in blood pressure can occur in individual cases during treatment with Flomaxtra XL, as a result of which, rarely, syncope can occur. At the first signs of orthostatic hypotension (dizziness, weakness), the patient should sit or lie down until the symptoms have disappeared.

Before therapy with Flomaxtra XL 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.

The treatment of severely renally impaired patients (creatinine clearance of less than 10 ml/min) should be approached with caution as these patients have not been studied.

The 'Intraoperative Floppy Iris Syndrome' (IFIS, a variant of small pupil syndrome) has been observed during cataract surgery in some patients on or previously treated with tamsulosin. IFIS may lead to increased procedural complications during the operation. The initiation of therapy with tamsulosin in patients for whom cataract surgery is scheduled is not recommended.

Discontinuing tamsulosin 1-2 weeks prior to cataract surgery is anecdotally considered helpful, but the benefit and duration of stopping of therapy prior to cataract surgery has not yet been established.

During pre-operative assessment, cataract surgeons and ophthalmic teams should consider whether patients scheduled for cataract surgery are being or have been treated with tamsulosin in order to ensure that appropriate measures will be in place to manage the IFIS during surgery.

No interactions have been seen when tamsulosin was given concomitantly with atenolol, enalapril, nifedipine or theophylline. Concomitant cimetidine brings about a rise in plasma levels of tamsulosin, and furosemide a fall, but as levels remain within the normal range, posology need not be changed.

In vitro, neither diazepam nor propranolol, trichlormethiazide, chlormadinon, amitryptyline, diclofenac, glibenclamide, simvastatin and warfarin change the free fraction of tamsulosin in human plasma. Neither does tamsulosin change the free fractions of diazepam, propranolol, trichlormethiazide, and chlormadinon.

No interactions at the level of hepatic metabolism have been seen during in vitro studies with liver microsomal fractions (representative of the cytochrome P₄₅₀-linked drug metabolising enzyme system), involving amitriptyline, salbutamol, glibenclamide and finasteride. Diclofenac and warfarin, however, may increase the elimination rate of tamsulosin.

There is a theoretical risk of enhanced hypotensive effect when given concurrently with drugs which may reduce blood pressure, including anaesthetic agents and other α₁-adrenoceptor antagonists.

Flomaxtra XL was evaluated in two double - blind placebo controlled trials. Adverse events were mostly mild and their incidence was generally low. The most commonly reported ADR was abnormal ejaculation occurring in approximately 2% of patients.

Suspected adverse reactions reported with Flomaxtra XL or an alternative formulation of tamsulosin, were:-

Nervous systems disorders

Common: dizziness, headache

Uncommon: syncope

Cardiac disorders

Uncommon: palpitations

Vascular disorders

Uncommon: postural hypotension

Respiratory disorders

Uncommon: rhinitis

Gastrointestinal disorders

Uncommon: nausea, vomiting, constipation, diarrhoea

Skin and subcutaneous tissue disorders

Uncommon: rash, pruritus, urticaria

Very rare: angioedema

Reproductive system disorders

Common: abnormal ejaculation

Very rare: priapism

General disorders

Common: asthenia

As with other alpha-blockers, drowsiness, blurred vision, dry mouth or oedema can occur.

During cataract surgery a small pupil situation, known as Intraoperative Floppy Iris Syndrome (IFIS), has been associated with therapy of tamsulosin during post-marketing surveillance.

Astellas Pharma

(POM)

11 August 2009