(Losartan Potassium IP 25mg / 50 mg)
Each film coated tablets contains:
(Losartan Potassium IP 25mg / 50 mg )
Tablet for Oral Use
Losartan reversibly and competitively prevents angiotensin II binding to the AT1 receptor in tissues like vascular smooth muscle and the adrenal gland. Losartan and its active metabolite bind the AT1 receptor with 1000 times more affinity than they bind to the AT2 receptor. The active metabolite of losartan is 10-40 times more potent by weight than unmetabolized losartan as an inhibitor of AT1 and is a non-competitive inhibitor. Losartan’s prevention of angiotensin II binding causes vascular smooth muscle relaxation, lowering blood pressure. Angiotensin II would otherwise bind to the AT1 receptor and induce vasoconstriction, raising blood pressure.
Absorption: Losartan is approximately 33% orally bioavailable. Losartan has a Tmax of 1 hour and the active metabolite has a Tmax of 3-4 hours. Taking losartan with food decreases the Cmax but does only results in a 10% decrease in the AUC of losartan and its active metabolite.
Distribution: The volume of distribution of losartan is 34.4±17.9L and 10.3±1.1L for the active metabolite and protein binding is 99%.
Metabolism: Undergoes extensive first pass hepatic metabolism, 14% is converted to an active metabolite, 4% excreted unchanged in urine, 6% excreted in urine as active metabolite.
Half Life: The terminal elimination half -life of losartan is 1.5-2.5 hours while the active metabolite has a half -life of 6-9 hours.
- To treat hypertension in patients older than 6 years
- Reduce the risk of stroke in patients with hypertension and left ventricular hypertrophy
- To treat diabetic nephropathy with elevated serum creatinine and proteinuria in patients with type 2 diabetes and hypertension
ADVERSE REACTION: lightheadedness, pain or burning when you urinate, nausea, weakness, tingly feeling, chest pain, irregular heartbeats, loss of movements, little or no urination, rapid weight gain, and swelling in your hands, feet or ankles, pain in your legs or back
DOSAGE AND ADMINISTRATION:
50 mg PO once a Day initially; may increase to up to 100 mg/day.Patients with possible intravascular depletion or receiving diuretics (eg, on diuretic therapy): 25 mg PO once a Day initially
Hypertension with Left Ventricular Hypertrophy
Indicated to reduce risk of stroke in patients with hypertension and left ventricular hypertrophy, but there is evidence that this benefit does not apply to Black patients. 50 mg PO once a Day initially; may increase to up to 100 mg/day
Hydrochlorothiazide 12.5 mg PO a Day may be added in combination; may increase to up to 25 mg/day
Nephropathy in Type 2 Diabetes
Indicated for diabetic nephropathy with an elevated serum creatinine and proteinuria (urinary albumin to creatinine ratio ≥300 mg/g) in patients with type 2 diabetes and a history of hypertension. 50 mg PO OD initially; may increase to up to 100 mg/day
- Hypersensitivity to Losartan Potassium, Pregnancy and Breast feeding, patients with renal artery stenosis, chronic kidney disease, severe congestive heart failure
WARNINGS AND PRECAUTIONS:
- When pregnancy is detected, discontinue Losartan as soon as possible
- Correct volume or salt depletion prior to administration of Losartan
- Monitor serum potassium periodically and treat appropriately
- Increased risk of hyperkalemia with concurrent use of potassium supplements or potassium sparing diuretics
- NSAIDs and rifampin may decrease antihypertensive effect.
- May increase the effects of Amiodarone, Fluoxetine, Glimepiride, Glipizide, Phenytoin, Sertraline and Warfarin.