Consumer medicine information

1. Why am I using BTC Tamsulosin SR?

BTC Tamsulosin SR contains the active ingredient tamsulosin and belongs to a group of medicines called alpha-blockers. BTC Tamsulosin SR is used in men who have a medical condition called benign prostatic hyperplasia (also known at BPH). In BPH the prostate gland is bigger than normal. BPH is NOT prostate cancer. For more information, see Section 1. Why am I using BTC Tamsulosin SR? in the full CMI.

2. What should I know before I use BTC Tamsulosin SR?

BTC Tamsulosin SR is for use by MEN only. If you are a woman or a child, do not take BTC Tamsulosin SR. If you are not sure whether you should start taking BTC Tamsulosin SR, you should contact your doctor.
There are a number of circumstances in which a person should not use this medicine or may need to use caution. It is important to understand if these apply to your before taking BTC Tamsulosin SR.
Do not use BTC Tamsulosin SR if you have ever had an allergic reaction to tamsulosin or any of the ingredients listed at the end of the CMI. For more information, see Section 2. What should I know before I use BTC Tamsulosin SR? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with BTC Tamsulosin SR and affect how it works.
A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How do I use BTC Tamsulosin SR?

• The usual dose is one tablet a day.

• The tablet should be swallowed whole, preferably with a glass of water. Do not crunch, bite or chew the tablet.

5. What should I know while using BTC Tamsulosin SR?

6. Are there any side effects?

There are a number of side effects associated with this medicine. It is important to be aware of them so that you can identify any symptoms if they occur (see the full CMI for more details). Some serious side effects may include prolonged painful erection of the penis, which is unrelated to sexual activity; swelling of the face, lips, mouth or throat which may cause difficulty in swallowing or breathing.
For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.

1 Name of Medicine

Tamsulosin hydrochloride.

2 Qualitative and Quantitative Composition

Each BTC Tamsulosin SR 400 microgram modified release tablet contains 400 microgram tamsulosin hydrochloride.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

BTC Tamsulosin SR 400 microgram are brown, round, biconvex film-coated tablets with debossing '0.4' on one side and 'SZ' on the other side.

4 Clinical Particulars

4.9 Overdose

Acute overdose with 5 mg tamsulosin hydrochloride has been reported. Acute hypotension (systolic blood pressure 70 mmHg), vomiting and diarrhoea were observed, which were treated with fluid replacement and the patient could be discharged the same day.
If acute hypotension occurs after overdosage, cardiovascular support should be given and maintained. Blood pressure can be restored and heart rate brought back to normal by lying the patient down. If this is insufficient then volume expanders and, when necessary, vasopressors could be administered. 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.
BTC Tamsulosin SR is a modified release formulation. The signs and symptoms of overdose may be delayed or prolonged from the time of ingestion.
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.
For information on the management of overdose, contact the Poison Information Centre on 131126 (Australia).

5 Pharmacological Properties

5.3 Preclinical Safety Data

Genotoxicity. In vivo and in vitro genotoxicity has been conducted.
Tamsulosin hydrochloride produced no evidence of genotoxic potential in assays for gene mutation (Ames reverse mutation test and mouse lymphoma thymidine kinase assay), chromosomal damage (Chinese hamster ovary cells and mouse micronucleus assay) and other genotoxic effects (unscheduled DNA repair synthesis and in vivo sister chromatid exchange).
Carcinogenicity. Carcinogenicity studies in mice and reproduction toxicity studies in rats have been conducted.
Oral (dietary) administration of tamsulosin for up to 2 years in rats and mice was associated with an increased incidence of pituitary adenoma, mammary gland hyperplasia, mammary gland fibroadenoma and (in mice only) mammary gland adenocarcinoma. These effects occurred at plasma tamsulosin concentrations (AUC) up to 10 times lower than those expected in men undergoing treatment with tamsulosin tablets, but they were observed only in female animals and are probably due to the hyperprolactinaemic effect of tamsulosin. It is not known if tamsulosin elevates prolactin during prolonged administration in humans. The relevance for human risk of the findings of prolactin-mediated endocrine tumours in female rodents is unknown.

6 Pharmaceutical Particulars

6.7 Physicochemical Properties

Tamsulosin hydrochloride is slightly soluble in water, freely soluble in formic acid, and slightly soluble in anhydrous ethanol. It is stable in an acid environment.
The pH of tamsulosin is 4.8-5.3 with a pKa of 8.4 (secondary amine) and 10.7 (sulphonamide) and a partition coefficient of 2.2.
Chemical structure.
https://stagingapi.mims.com/au/public/v2/images/fullchemgif/CSTAMSUH.gif Chemical formula: 5-[(2R)-2-[[2-(2-Ethoxyphenoxy)ethyl] amino]propyl]-2-methoxybenzenesulfonamide hydrochloride.
Molecular formula: C₂₀H₂₈N₂O₅S.HCl.
Molecular weight: 445.0.
CAS number. 106463-17-6.

7 Medicine Schedule (Poisons Standard)

S4 - Prescription Only Medicine.

Summary Table of Changes

https://stagingapi.mims.com/au/public/v2/images/fulltablegif/BTCTMSST.gif