Omnex® MR
Treatment of BPH

Pharmacodynamic properties:
¤ Mechanism of Action:

  • Tamsulosin, an alpha1 adrenoceptor blocking agent, exhibits selectivity for alpha1 receptors in the human prostate. At least three discrete alpha1 - adrenoceptor subtypes have been identified:  alpha1A , alpha1B and alpha1D ; their distribution differs between human organs and tissue.  Approximately 70% of the alpha1-receptors in human prostate are of the alpha1A subtype.

Pharmacokinetic properties:

  • Absorption of tamsulosin hydrochloride from Omnex® MR capsules 0.4 mg is essentially complete (>90%) following oral administration under fasting conditions.
  • Tamsulosin hydrochloride exhibits linear kinetics following single and multiple dosing, with achievement of steady-state concentrations by the fifth day of once-a-day dosing.


  • The mean steady-state apparent volume of distribution of tamsulosin hydrochloride after intravenous administration to ten healthy male adults was 16 L, which is suggestive of distribution into extracellular fluids in the body
  • Tamsulosin hydrochloride is extensively bound to human plasma proteins (94% to 99%).


  • Tamsulosin hydrochloride is extensively metabolized by cytochrome P450 enzymes in the liver and less than 10% of the dose is excreted in urine unchanged.


  • On administration of the radiolabeled dose of tamsulosin hydrochloride to four healthy volunteers, 97% of the administered radioactivity was recovered, with urine (76%) representing the primary route of excretion compared to feces (21%) over 168 hours. Following intravenous or oral administration of an immediate-release formulation, the elimination half-life of tamsulosin hydrochloride in plasma range from five to seven hours. Because of absorption rate-controlled pharmacokinetics with Omnex® MR capsules, the apparent half-life of tamsulosin hydrochloride is approximately 9 to 13 hours in healthy volunteers and 14 to 15 hours in the target population. 

Each capsule of Omnex® MR contains:

  • Tamsulosin hydrochloride 0,4 mg.
  • Omnex® MR capsules are indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). These signs and symptoms may include difficulty urinating (Poor stream), dribbling, urgency and having to urinate frequently at night as well as during the day.
  • Omnex® MR capsules are not indicated for the treatment of hypertension.
  • Omnex® MR capsules are contraindicated in patients known to be hypersensitive to tamsulosin hydrochloride or any component of Omnex® MR capsules.

Cytochrome P450 Inhibition:

Tamsulosin is extensively metabolized, mainly by CYP3A4 and CYP2D6.

  • The effects of coadministration of both a CYP3A4 and a CYP2D6 inhibitor with Omnex® MR capsules have not been evaluated. However, there is a potential for significant increase in tamsulosin exposure when Omnex® MR 0.4 mg is coadministered with a combination of both CYP3A4 and CYP2D6 inhibitors.

cimetidine :

  • Treatment with cimetidine resulted in a significant decrease (26%) in the clearance of tamsulosin hydrochloride, which resulted in a moderate increase in tamsulosin hydrochloride  AUC (44%).

phosphodiesterase 5 (PDE5 )inhibitors:

  • Caution should be exercised when phosphodiesterase type 5 inhibitors, including Omnex® MR , are co-administered with PDE5 inhibitors.
  • Alpha-adrenergic blockers and PDE5 inhibitors are both vasodilators that can lower blood pressure. Concomitant use of these two classes of drugs can potentially cause hypotension.


  • Caution should be exercised with concomitant administration of warfarin and Omnex® MR capsules.

Nifedipine, Atenolol, Enalapril:

  • Dosage adjustments are not necessary when Omnex® MR capsules are administered concomitantly with nifedipine, atenolol, or enalapril.

Digoxin and Theophylline:

  • Dosage adjustments are not necessary when a Omnex® MR capsule is administered concomitantly with digoxin or theophylline .


  • Omnex® MR capsules had no effect on the pharmacodynamics (excretion of electrolytes) of furosemide. While furosemide produced an 11% to 12% reduction in tamsulosin hydrochloride C max and AUC, these changes are expected to be clinically insignificant and do not require adjustment of the Omnex® MR capsules dosage 
  • Omnex® MR is not indicated for use in pregnant and lactating women.
  • Tamsulosin hydrochloride is present in the milk of lactating rats.

Like all medicines, Omnex® MR can cause sides effects, although not everybody gets them.
Common (less than 1 in 10, more than 1 in 100 (1 - 10%)):

  • Dizziness, particularly when going to sit or stand up.
  • Abnormal ejaculation. The latter means that semen does not leave the body via the urethra, but instead goes into the bladder. This phenomenon is harmless.

Uncommon (More than 1 in 1000, less than 1 in 100 (0,1 - 1%)):

  • Headache, palpitations (the heart beats more rapidly than normal and it is also noticeable ), reduced blood pressure e.g. when getting up quickly from a seating or lying position sometimes associated with dizziness; runny or blocked nose (rhinitis), diarrhoea, feeling sick and vomiting, constipation, weakness (asthenia), rashes, itching and hives(urticaria).

Rare (More than 1 in 10,000, less than 1 in 1000 (0,01 - 0,1%)):

  • Faintness and sudden local swelling of the soft tissues of the body (e.g. the throat or tongue) difficult breathing and /or itching and rash, often as an allergic reaction (angioedema).

Vary rare (less than 1 in 10,000 (<0,01%)):

  • Priapism (painful prolonged unwanted erection for which immediate medical treatment is required).
  • Rash, inflammation and blistering of the skin and / or mucous membrane of the lips, eyes, mouth, nasal passages or genitals (Stevens-Johnson syndrome).
  • Abnormal irregular heart rhythm (atrial fibrillation, arrhythmia, tachycardia), difficult breathing (dyspnoea).


  • Overdosage with tamsulosin hydrochloride can potentially result in severe hypotensive Laboratory data indicate that tamsulosin is 94% to 99% protein bound; therefore dialysis is unlikely to be of benefit. 
  • Gastric lavage can be applied or activated charcoal or an osmotic laxative may be given.
  • Laboratory data indicate that tamsulosin is 94% to 99% protein bound; therefore dialysis is unlikely to be of benefit.

Omnex® MR capsules should not be crushed, chewed or opened.

  • One capsule (0.4 mg) once daily to be taken half an hour after the same meal each day.
  • Can be increased to 0.8 mg once daily for patients who fail to respond to the 0.4 mg dose after 2 to 4 weeks of dosing.
  • If discontinued or interrupted for several days, therapy should start again with the0.4 mg once-daily dose.

Women & Children:

  • Omnex® MR capsules are not recommended for women and children.


  • Patients beginning treatment with Omnex® MR capsules should be cautioned to avoid situations in which injury could result when syncope occurs.

Screening for Prostate Cancer:

  • Prostate cancer and BPH frequently coexist; therefore, patients should be screened for the presence of prostate cancer prior to treatment with Omnex® MR capsules and at regular intervals afterwards.

Intraoperative Floppy Iris Syndrome (IFIS):

  • IFIS may increase the risk of eye complications during and after the operation. 

Sulfa Allergy:

  • In patients with sulfa allergy, allergic reaction to Omnex® MR capsules has been rarely reported.
  • If a patient reports a serious or life-threatening sulfa allergy, caution is warranted when administering Omnex® MR capsules.
  • Omnex® MR ( Blister of 10 capsules, pack of three Blister).
  • Store at a temperature not exceeding 25 °C, protect from light.