Getzar

Losartan potassium.

Pharmacokinetics: Losartan potassium is an angiotensin II receptor antagonist with antihypertensive activity due mainly to selective blockade of AT₁ receptors and the consequent reduced effect of angiotensin II.
Losartan potassium is readily absorbed from the GIT following oral administration, with an oral bioavailability of about 33%. It undergoes first-pass metabolism to form an active carboxylic acid metabolite E-3174 (EXP-3174), which has greater pharmacological activity than losartan and some inactive metabolites. Metabolism is primarily by cytochrome P-450 isoenzymes CYP2C9 and CYP3A4. Peak plasma concentrations of losartan and E-3174 occur about 1 hr and 3-4 hrs, respectively, after an oral dose. Both losartan and E-3174 are >98% bound to plasma proteins. Losartan is excreted in the urine and in the feces via bile, as unchanged drug and metabolites. Following oral dosing, about 35% of the dose is excreted in the urine and about 60% in the feces. The terminal elimination t_½ of losartan and E-3174 are about 1.5-2.5 hrs and 3-9 hrs, respectively.

Management of hypertension.

Usual Dose: 50 mg once daily.
The dose may be increased, if necessary, to 100 mg daily as a single dose or in 2 divided doses.
Elderly (>75 years) and Patients with Moderate to Severe Renal Impairment (Creatinine Clearance <20 mL/min): Initial Dose: 25 mg daily.
Intravascular Fluid Depletion: Initial Dose: 25 mg daily.

Pregnancy.

Getzar should be used with care, if at all, during breastfeeding. It should be used with caution in patients with renal artery stenosis. Reduced doses may be required in patients with renal or hepatic impairment. Patients with volume depletion may experience hypotension.

Use in Pregnancy: Getzar is contraindicated in pregnancy.
Use in Lactation: Getzar should be used with care, if at all, during breastfeeding.

Adverse effects include dizziness and dose-related orthostatic hypotension. Hypotension may occur particularly in patients with volume depletion (eg, those who have received high-dose diuretics). Getzar may cause hyperkalemia in patients with renal disease. Other adverse effects that have been reported with angiotensin II receptor antagonist include respiratory tract disorder, back pain, GI disturbances, fatigue and neutropenia.

Store at temperatures not exceeding 30°C.

Angiotensin II Antagonists

C09CA01 - losartan ; Belongs to the class of angiotensin II receptor blockers (ARBs). Used in the treatment of cardiovascular disease.

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