LOSARTAN POTASSIUM TABLETS
Losartan potassium is an orally active, nonpeptide angiotensin II receptor antagonist and a novel antihypertensive agent.
Each film-coated tablet contains Losartan Potassium USP 25 mg or 50mg.
Angiotensin II is a potent vasoconstrictor, formed from angiotensin I in a reaction catalyzed by angiotensin converting enzyme [ACE]. It is the primary vasoactive hormone of the renin-angiotensin system [RAS] and an important component in the pathophysiology of hypertension. Angiotensin II also stimulates aldosterone secretion by the adrenal cortex.
Losartan and its principal active metabolite block the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor found in many tissues, (e.g., vascular smooth muscle, adrenal gland).
Both Losartan and its principal active metabolite have a much greater affinity (about 1000-fold) for the AT1 receptor than for the AT2 receptor. In vitro binding studies indicate that Losartan is a reversible, competitive inhibitor of the AT1 receptor. The active metabolite is 10 to 40 times more potent by weight than Losartan and appears to be a reversible, non-competitive inhibitor of the AT1 receptor.
Losartan is an orally active agent that undergoes substantial first-pass metabolism by cytochrome P450 enzymes. It is converted, in part, to an active carboxylic acid metabolite that is responsible for most of the angiotensin II receptor antagonism that follows Losartan treatment.
LOSATRUST is indicated for the treatment of hypertension. It may be used alone or in combination with other anti hypertensive agents.
The usual starting dose of LOSATRUST is 50 mg once daily. A dose of 25 mg may be used in patients with possible depletion of intravascular volume (e.g. patients treated with diuretics) and patients with a history of hepatic impairment. LOSATRUST can be administered once or twice daily with total daily doses ranging from 25 mg to 100mg.
Hypersensitivity to Losartan or any of the components of this product.
Infants with histories of in utero exposure to an angiotensin II receptor antagonist should be closely observed for hypotension, oliguria, and hyperkalemia. If oliguria occurs, attention should be directed toward support of blood pressure and renal perfusion. Exchange transfusion or dialysis may be required.
Impaired Hepatic Function
Based on pharmacokinetic data, which demonstrate significantly increased plasma concentrations of Losartan in cirrhotic patients, a lower dose should be considered for patients with impaired liver function.
Impaired Renal Function
As a consequence of inhibiting the renin-angiotensin-aldosterone system [RAAS], changes in renal function have been reported in susceptible individuals treated with Losartan; in some patients, these changes in renal function were reversible upon discontinuation of therapy. In patients whose renal function may depend on the activity of the RAAS (e.g., patients with severe congestive heart failure), treatment with ACE inhibitors has been associated with oliguria and/or progressive azotemia and (rarely) with acute renal failure and/or death. Similar outcomes have been reported with Losartan.
Electrolyte imbalances are common in patients with renal impairment, with or without diabetes, and should be addressed.
No significant interactions have been observed during concomitant administration of Losartan with hydrochlorothiazide, digoxin, warfarin and phenobarbital.
Drugs acting on the RAS can cause fetal and neonatal morbidity and death when given to pregnant women. When pregnancy is detected, Losartan should be discontinued.
It is not known whether Losartan is secreted in human milk, but Losartan and its metabolites have been found in the rat milk. Because of the potential for adverse effects on the nursing infant, a decision must be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
Safety and effectiveness of Losartan in pediatric patients have not been established.
Losartan is well tolerated. The commonly observed adverse effects include: headache, dizziness, abdominal pain, asthenia/fatigue, occasional increases in liver enzymes, blood urea or serum creatinine. Angioedema has been reported rarely in patients with Losartan. Hyperkalemia has also been reported.
Limited data is available regarding overdosage in humans. Likely manifestations include hypotension and tachycardia; bradycardia could occur due to vagal stimulation. If symptomatic hypotension should occur, supportive therapy should be instituted. Neither Losartan nor its active metabolite can be removed by dialysis.
LOSATRUST 25/50 is available in Blister pack of 1 x 10, 3 x 10, 10 x 10 & 10 x 1 x 10 tablets.
Store at temperature between 15-30°C. In a dry and dark place. Keep medicines out of the reach of children.
LOSATRUST 25 NAFDAC Reg. No.: A4-3317
LOSATRUST 50 NAFDAC Reg. No.: A4-2834
AL-TINEZ PHARMA LTD.
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CENTAUR PHARMACEUTICALS PVT. LTD.
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