Product Information
Registration Status: ActiveSIN11674P
HYTRIN TABLET 1mg is approved to be sold in Singapore with effective from 2001-09-21. It is marketed by ABBOTT LABORATORIES (SINGAPORE ) PTE LTD, with the registration number of SIN11674P.
This product contains Terazosin 1mg in the form of TABLET. It is approved for ORAL use.
This product is manufactured by Aesica Queenborough LTD in UNITED KINGDOM.
It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.
Product Reference
Important Note: For generic product, the SPC/PIL provided may not be brand specific.
{{/items}} {{^items}}Description
Terazosin is a selective alpha1-antagonist used for treatment of symptoms of benign prostatic hyperplasia (BPH). It also acts to lower blood pressure, so it is a drug of choice for men with hypertension and prostate enlargement. It works by blocking the action of adrenaline on smooth muscle of the bladder and the blood vessel walls.
Indication
For the treatment of symptomatic BPH and mild to moderate hypertension.
Mechanism of Action
In general, α1-adrenergic receptors mediate contraction and hypertrophic growth of smooth muscle cells. α1-Receptors are 7-transmembrane domain receptors coupled to G proteins, Gq/11. Three α1-receptor subtypes, which share approximately 75% homology in their transmembrane domains, have been identified: α1A (chromosome 8), α1B (chromosome 5), and α1D (chromosome 20). Terazosin is the first α1-receptor antagonist to demonstrate selectivity for the α1A-receptor. All three receptor subtypes appear to be involved in maintaining vascular tone. The α1A-receptor maintains basal vascular tone while the α1B-receptor mediates the vasocontrictory effects of exogenous α1-agonists. Activation of α1-receptors activates Gq-proteins, which results in intracellular stimulation of phospholipases C, A2, and D. This results in mobilization of Ca2+ from intracellular stores, activation of mitogen-activated kinase and PI3 kinase pathways and subsequent vasoconstriction. Terozosin produces its pharmacological effects by inhibiting α1A-receptor activation. Inhibition of these receptors in the vasculature and prostate results in muscle relaxation, decreased blood pressure and improved urinary outflow in symptomatic benign prostatic hyperplasia.
Pharmacokinetics
- Absorption
- Essentially completely absorbed in man (90% bioavailability).
- Distribution
- Metabolism
- Hepatic. One of the four metabolites identified (piperazine derivative of terazosin) has antihypertensive activity.
- Elimination
Toxicity
LD50=259.3mg/kg (IV in mice)
Active Ingredient/Synonyms
1-(4-Amino-6,7-dimethoxy-2-quinazolinyl)-4-((tetrahydro-2-furanyl)carbonyl)piperazine | Terazosina | Terazosine | Térazosine | Terazosinum | Terazosin |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.