OSARTAN-HZ

Losartan Potassium + Hydrochlorothiazide

Description: 

Osartan-HZ (Losartan Potassium + Hydrochlorothiazide) combines an angiotensin II receptor blocker, Losartan Potassium and a diuretic, Hydrochlorothiazide.

Composition: 

Osartan-HZ Tablet: Each tablet contains Losartan Potassium USP 50 mg and Hydrochlorothiazide BP 12.5 mg.

Pharmacology:

Losartan Potassium is the first orally active angiotensin-II receptor (type-AT₁) antagonist. Angiotensin-II is a potent vasoconstrictor which is the primary vasoactive hormone of the renin-angiotensin system and an important component in the patho-physiology of hypertension. Osartan and its principal active metabolite block the vasoconstrictor and aldosterone secreting effects of angiotensin-II to the AT₁ receptor.

Hydrochlorothiazide is a thiazide diuretic. Thiazides affect the renal tubular mechanisms of electrolyte reabsorption, directly increasing excretion of sodium and chloride in approximately equivalent amounts. Indirectly, the diuretic action of hydrochlorothiazide reduces plasma volume, with consequent increases in plasma renin activity, aldosterone secretion, urinary potassium loss, and decreases in serum potassium. The renin-aldosterone link is mediated by angiotensin II, so co-administration of Candesartan tends to reverse the potassium loss associated with Hydrochlorothiazide.

Indication:  

Osartan-HZ is indicated for the treatment of hypertension. This fixed dose combination is not indicated for initial therapy.

Dosage and administration:  

Hypertension: The usual dose of Osartan-HZ is one tablet daily. For patients who do not respond adequately to one tablet the dosage may be increased to two tablets of Osartan-HZ once daily. The maximum dose is two tablets of Osartan-HZ once daily. In general the antihypertensive effect is attained within three weeks after initiation of therapy.

No initial dose adjustment of Osartan-HZ is necessary for elderly patients. But maximum dose of two tablets of once daily dose should not be used as initial therapy in elderly patients.

Use in patients with renal impairment: The usual regimens of therapy with Osartan-HZ may be followed as long as the patient’s creatinine clearance is > 30ml/min. In patients with more severe renal impairm,ent, loop diuretics are preferred to thiazides. In that case, hydrochlorothiazide is not recommended.     

Use in patients with hepatic impairment: The combination of losartan and hydrochlorothiazide is not recommended for titration in patients with hepatic impairment because the appropriate 25 mg starting dose of losartan cannot be given.

Severe hypertension: The starting dose of Osartan-HZ for initial treatment of severe hypertension is one tablet of Osartan-HZ once daily. For patients who do not respond adequately to this dose after 2 to 4 weeks of therapy, the dosage may be increased to two tablets of Osartan-HZ once daily. The maximum dose is two tablets of Osartan-HZ once daily.

Osartan-HZ may be administered with other antihypertensive agents.

Osartan-HZ may be administered with or without food.   

Contraindications:  

Osartan-HZ is contraindicated in patients who are hypersensitive to any component of this product. Because of the hydrochlorothiazide component, this product is contraindicated in patients with anuria or hypersensitivity to other sulfonamide-derived drugs.

Drug interactions:

Losartan potassium: No significant drug-drug pharmacokinetic interactions have been found in interaction studies with hydrochlorothiazide, digoxin, warfarin, cimetidine and phenobarbitol. 

Hydrochlorothiazide: Alcohol, barbiturates, or narcotics– Potentiation of orthostatic hypotension may occur. Antidiabetic drugs (oral agents and insulin)– Dosage adjustment of the antidiabetic drug may be required. Other antihypertensive drugs– Additive effect or potentiation. Cholestyramine and colestipol resins– Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins. Corticosteroids, ACTH– Intensified electrolyte depletion, particularly hypokalemia. Skeletal muscle relaxants, tubocurarine– Possible increased responsiveness to the muscle relaxant. Lithium –Diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity. NSAID can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics.

Side-effects:  

In clinical trials with losartan potassium and hydrochlorothiazide, no adverse experience peculiar to this combination have been observed. The overall incidence of adverse experiences reported with the combination was comparable to placebo.  

Precautions:  

Periodic determination of serum electrolytes to detect possible electrolyte imbalance should be performed at appropriate intervals.

In diabetic patients dosage adjustments of insulin or oral hypoglycemic agents may be required. Hyperglycemia may occur with thiazide diuretics.

If progressive renal impairment becomes evident, consider withholding or discontinuing diuretic therapy.

Increases in cholesterol and triglyceride levels may be associated with thiazide diuretic therapy.

Use in pregnancy: 

Not recommended.

Use in lactation: 

Not recommended.

Use in pediatric patients:  

Safety and effectiveness in pediatric patients have not been established. 

Storage:

Store below 40⁰C & away from light. Keep out of the reach of children.   

Packing: