Drugs Xagena
Flomax Relief ( Tamsulosin ) is an alpha1-adrenoceptor antagonist, indicated for the treatment of functional symptoms of benign prostatic hyperplasia ( BPH ) in male 45 to 75 years.
Tamsulosin binds selectively and competitively to postsynaptic alpha1-receptors, in particular to the subtype alpha1A, which bring about relaxation of the smooth muscle of the prostate, whereby tension is reduced.
Flomax Relief increases maximum urinary flow rate by reducing smooth muscle tension in prostate and urethra and thereby relieving obstruction. It also improves the complex of irritative and obstructive symptoms in which bladder instability and tension of the smooth muscles of the lower urinary tract play an important role.
Alpha1-blockers can reduce blood pressure by lowering peripheral resistance. No reduction in blood pressure of any clinical significance was observed during studies with Flomax Relief.
Flomax Relief should be taken after the same meal each day, one capsule daily. The capsule should be swallowed whole and should not be crunched or chewed as this will interfere with the modified release of the active ingredient.
Contraindications
Hypersensitivity to Tamsulosin hydrochloride, including drug-induced angioedema, or any other component of the product; a history of orthostatic hypotension; severe hepatic insufficiency.
Special warnings and precautions for use
As with other alpha1 blockers, a reduction in blood pressure can occur in individual cases during treatment with Flomax Relief, 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.
The IFIS ( Intraoperative Floppy Iris Syndrome, a variant of small pupil syndrome ) has been observed during cataract and glaucoma surgery in some patients on or previously treated with Tamsulosin hydrochloride. IFIS may increase the risk of eye complications during and after the operation.
Discontinuing Tamsulosin hydrochloride 1-2 weeks prior to cataract or glaucoma surgery is anecdotally considered helpful, but the benefit of treatment discontinuation has not been established. IFIS has also been reported in patients who had discontinued Tamsulosin for a longer period prior to the surgery.
The initiation of therapy with Tamsulosin hydrochloride in patients for whom cataract or glaucoma surgery is scheduled is not recommended. During pre-operative assessment, surgeons and ophthalmic teams should consider whether patients scheduled for cataract or glaucoma 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.
Tamsulosin hydrochloride should not be given in combination with strong inhibitors of CYP3A4 ( e.g. Ketoconazole ) in patients with poor metaboliser CYP2D6 phenotype.
Tamsulosin hydrochloride should be used with caution in combination with strong ( e.g. Ketoconazole ) and moderate ( e.g. Erythromycin ) inhibitors of CYP3A4.
Interaction with other medicinal products and other forms of interaction
Interaction studies have only been performed in adults.
No interactions have been seen when Flomax Relief was given concomitantly with either Atenolol, Enalapril, 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.
Diclofenac and Warfarin, however, may increase the elimination rate of Tamsulosin.
Concomitant administration of Tamsulosin hydrochloride with strong inhibitors of CYP3A4 may lead to increased exposure to Tamsulosin hydrochloride.
Concomitant administration with Ketoconazole ( a known strong CYP3A4 inhibitor ) resulted in an increase in AUC and Cmax of Tamsulosin hydrochloride by a factor of 2.8 and 2.2 respectively.
Tamsulosin hydrochloride should not be given in combination with strong inhibitors of CYP3A4 ( e.g. Ketoconazole ) in patients with poor metaboliser CYP2D6 phenotype.
Tamsulosin hydrochloride should be used with caution in combination with strong ( e.g. Ketoconazole ) and moderate ( e.g. Erythromycin ) inhibitors of CYP3A4.
Concomitant administration of Tamsulosin hydrochloride with Paroxetine, a strong inhibitor of CYP2D6, resulted in a Cmax and AUC of Tamsulosin that had increased by a factor of 1.3 and 1.6, respectively, but these increases are not considered clinically relevant.
There is a theoretical risk of enhanced hypotensive effect when given concurrently with drugs which may reduce blood pressure including anaesthetic agents, other alpha1-adrenoceptor antagonists.
Pregnancy and lactation
Flomax Relief is not indicated for use in women.
Ejaculation disorders have been observed in short and long term clinical studies with Tamsulosin. Events of ejaculation disorder, retrograde ejaculation and ejaculation failure have been reported in the post authorisation phase.
Undesirable effects
The side effects of Flomax Relief include: a) Common: dizziness ( 1.3% ) and ejaculation disorders ( including retrograde ejaculation and ejaculation failure ); Uncommon: headache, palpitations, orthostatic hypotension, rhinitis, constipation, diarrhoea, nausea, vomiting, rash, pruritus, urticaria,asthenia.
As with other alpha-blockers, drowsiness or oedema can occur.
During cataract and glaucoma surgery a small pupil situation, known as IFIS, has been associated with therapy of Tamsulosin during post-marketing surveillance.
In addition to the adverse events listed above, atrial fibrillation, arrhythmia, tachycardia and dyspnoea have been reported in association with Tamsulosin use.
Because these spontaneously reported events are from the worldwide post-marketing experience, the frequency of events and the role of Tamsulosin in their causation cannot be estimated from the available data. ( Xagena )
Source: MHRA / NHS, 2015
XagenaMedicine_2015
