ATACAND PLUS TABLET

Product Information

Registration Status: Active

ATACAND PLUS TABLET is approved to be sold in Singapore with effective from 2000-08-26. It is marketed by ASTRAZENECA SINGAPORE PTE LTD, with the registration number of SIN11383P.

This product contains Candesartan 16mg, and Hydrochlorothiazide 12.5mg in the form of TABLET. It is approved for ORAL use.

This product is manufactured by ASTRAZENECA AB in SWEDEN.

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.

Candesartan
Hydrochlorothiazide

Description

Candesartan is an angiotensin-receptor blocker (ARB) that may be used alone or with other agents to treat hypertension. It is administered orally as the prodrug, candesartan cilexetil, which is rapidly converted to its active metabolite, candesartan, during absorption in the gastrointestinal tract. Candesartan lowers blood pressure by antagonizing the renin-angiotensin-aldosterone system (RAAS); it competes with angiotensin II for binding to the type-1 angiotensin II receptor (AT1) subtype and prevents the blood pressure increasing effects of angiotensin II. Unlike angiotensin-converting enzyme (ACE) inhibitors, ARBs do not have the adverse effect of dry cough. Candesartan may be used to treat hypertension, isolated systolic hypertension, left ventricular hypertrophy and diabetic nephropathy. It may also be used as an alternative agent for the treatment of heart failure, systolic dysfunction, myocardial infarction and coronary artery disease.

Indication

May be used as a first line agent to treat uncomplicated hypertension, isolated systolic hypertension and left ventricular hypertrophy. May be used as a first line agent to delay progression of diabetic nephropathy. Candesartan may be also used as a second line agent in the treatment of congestive heart failure, systolic dysfunction, myocardial infarction and coronary artery disease in those intolerant of ACE inhibitors.

Mechanism of Action

Candesartan selectively blocks the binding of angiotensin II to AT1 in many tissues including vascular smooth muscle and the adrenal glands. This inhibits the AT1-mediated vasoconstrictive and aldosterone-secreting effects of angiotensin II and results in an overall decrease in blood pressure. Candesartan is greater than 10,000 times more selective for AT1 than AT2. Inhibition of aldosterone secretion may increase sodium and water excretion while decreasing potassium excretion.

Pharmacokinetics

Absorption
Following administration of the candesartan cilexetil prodrug, the absolute bioavailability of candesartan was estimated to be 15%. Food with a high fat content has no effect on the bioavailability of candesartan from candesartan cilexetil.
Distribution
* 0.13 L/kg
Metabolism
The prodrug candesartan cilexetil undergoes rapid and complete ester hydrolysis in the intestinal wall to form the active drug, candesartan. Elimination of candesartan is primarily as unchanged drug in the urine and, by the biliary route, in the feces. Minor hepatic metabolism of candesartan (<20%) occurs by O-deethylation via cytochrome P450 2C9 to form an inactive metabolite. Candesartan undergoes N-glucuronidation in the tetrazole ring by uridine diphosphate glucuronosyltransferase 1A3 (UGT1A3). O-glucuronidation may also occur. 75% of candesartan is excreted as unchanged drug in urine and feces.
Elimination

Clearance

* 0.37 mL/min/kg

Toxicity

No lethality was observed in acute toxicity studies in mice, rats and dogs given single oral doses of up to 2000 mg/kg of candesartan cilexetil or in rats given single oral doses of up to 2000 mg/kg of candesartan cilexetil in combination with 1000 mg/kg of hydrochlorothiazide. In mice given single oral doses of the primary metabolite, candesartan, the minimum lethal dose was greater than 1000 mg/kg but less than 2000 mg/kg.

Active Ingredient/Synonyms

Candesartan cilexetil | Candesartan cilexetil |


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.


Description

A thiazide diuretic often considered the prototypical member of this class. It reduces the reabsorption of electrolytes from the renal tubules. This results in increased excretion of water and electrolytes, including sodium, potassium, chloride, and magnesium. It has been used in the treatment of several disorders including edema, hypertension, diabetes insipidus, and hypoparathyroidism. [PubChem]

Indication

For the treatment of high blood pressure and management of edema.

Mechanism of Action

Hydrochlorothiazide, a thiazide diuretic, inhibits water reabsorption in the nephron by inhibiting the sodium-chloride symporter (SLC12A3) in the distal convoluted tubule, which is responsible for 5% of total sodium reabsorption. Normally, the sodium-chloride symporter transports sodium and chloride from the lumen into the epithelial cell lining the distal convoluted tubule. The energy for this is provided by a sodium gradient established by sodium-potassium ATPases on the basolateral membrane. Once sodium has entered the cell, it is transported out into the basolateral interstitium via the sodium-potassium ATPase, causing an increase in the osmolarity of the interstitium, thereby establishing an osmotic gradient for water reabsorption. By blocking the sodium-chloride symporter, hydrochlorothiazide effectively reduces the osmotic gradient and water reabsorption throughout the nephron.

Pharmacokinetics

Absorption
50-60%
Distribution
Metabolism
Hydrochlorothiazide is not metabolized.
Elimination

Toxicity

The most common signs and symptoms observed are those caused by electrolyte depletion (hypokalemia, hypochloremia, hyponatremia) and dehydration resulting from excessive diuresis. If digitalis has also been administered, hypokalemia may accentuate cardiac arrhythmias. The oral LD50 of hydrochlorothiazide is greater than 10 g/kg in the mouse and rat.

Active Ingredient/Synonyms

HCTZ | Hydrochlorothiazide |


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.

References

  1. Health Science Authority of Singapore - Reclassified POM
  2. Drugbank