Losartan Potassium is an orally active, nonpeptide angiotensin II (A II) receptor antagonist. It is the first of a new class of drugs introduced for clinical use in hypertension. This novel agent binds competitively and selectively to the A II subtype I [AT1] receptor, thereby blocking A IIinduced physiological effects. An active metabolite of Losartan, EXP 3174, contributes substantially to its antihypertensive effect, which persists throughout 24 hours after once daily administration. Unlike ACE inhibitors, they do not inhibit the breakdown of bradykinin and other kinins, and thus do not appear to cause the persistent dry cough, which commonly complicates ACE inhibitor therapy.
Dosage & Administration
Losartan is effective in all grades of hypertension and congestive heart failure. It may be used alone or in combination with other antihypertensive agents. It is an effective alternative for patients who have to discontinue an ACE inhibitor because of persistent dry cough.
The usual starting dose of Losartan is 50 mg once daily. Some patients may receive an additional benefit by increasing the dose to 100 mg once daily. In patients with possible depletion of intravascular volume (e.g. patients treated with diuretics) and in patients with a history of hepatic impairment, a lower initial dose of 25 mg is recommended. No initial dosage adjustment is necessary for elderly patients (upto 75 years) or for patients with renal impairment, including patients on dialysis. Losartan may be administered with or without food.
Losan is contraindicated in patients who are hypersensitive to any component of this product.
Sodium and/or volume depleted patients, such as, those receiving high doses of diuretics, symptomatic hypotension may occur in rare cases after initiation of therapy. Sodium and/or volume depletion should be corrected before starting treatment with Losartan for example, by reducing the diuretic dose. If hypotension occurs, the patient should be placed in the supine position and, if necessary, given an IV infusion of normal saline. Treatment can be continued once the blood pressure has stabilized. A lower dose should be considered for patients with a history of hepatic impairment.
Use Pregnancy Lactation
Losan is contraindicated during pregnancy. It should not be prescribed during lactation as there is no information in human on the passage of Losan into breast milk.
No drug interactions of clinical significance has been identified. Drugs which have been studied in clinical pharmacokinetic trials include hydrochlorothiazide, digoxin, warfarin, cimetidine, ketoconazole and phenobarbital.
The side effects with Losartan are mild and rare. In controlled clinical trial in patients with essential hypertension, dizziness was the only side effect reported that occurred with an incidence greater than placebo in 1% or more of patients treated with Losartan. Rarely rash was reported.
Losan 25: Each film-coated tablet contains Losartan Potassium USP 25 mg. Losan 50: Each film-coated tablet contains Losartan Potassium USP 50 mg. Losan 25: Box containing 3 x 10 tablets in blister pack. Losan 50: Box containing 3 x 10 tablets in blister pack.