n the basis of differences in the populations other than race or on any imbalances between treatment groups. In addition, blood pressure reductions in both treatment groups were consistent between Black and non-Black patients. Given the difficulty in interpreting subset differences in large trials, it cannot be known whether the observed difference is the result of chance. However, the LIFE study provides no evidence that the benefits of losartan potassium on reducing the risk of cardiovascular events in hypertensive patients with left ventricular hypertrophy apply to Black patients [see Clinical Studies (14.2)].
8.7 Renal ImpairmentPatients with renal insufficiency have elevated plasma concentrations of losartan and its active metabolite compared to subjects with normal renal function. No dose adjustment is necessary in patients with renal impairment unless a patient with renal impairment is also volume depleted [see Dosage and Administration (2.3), Warnings and Precautions (5.3) and Clinical Pharmacology (12.3)].
8.8 Hepatic ImpairmentThe recommended starting dose of losartan potassium is 25 mg in patients with mild-to-moderate hepatic impairment. Following oral administration in patients with mild-to-moderate hepatic impairment, plasma concentrations of losartan and its active metabolite were, respectively, 5 times and 1.7 times those seen in healthy volunteers. Losartan potassium has not been studied in patients with severe hepatic impairment [see Dosage and Administration (2.4) and Clinical Pharmacology (12.3)].
10 OVERDOSAGE
Significant lethality was observed in mice and rats after oral administration of 1000 mg/kg and 2000 mg/kg, respectively, about 44 and 170 times the maximum recommended human dose on a mg/m2 basis.
Limited data are available in regard to overdosage in humans. The most likely manifestation of overdosage would be hypotension and tachycardia; bradycardia could occur from parasympathetic (vagal) stimulation. If symptomatic hypotension should occur, supportive treatment should be instituted.
Neither losartan nor its active metabolite can be removed by hemodialysis.
11 DESCRIPTION
Losartan potassium is an angiotensin II receptor blocker acting on the AT1 receptor subtype. Losartan potassium, a non-peptide molecule, is chemically described as 2-butyl-4-chloro-1-[p-(o-1H tetrazol-5-ylphenyl)benzyl]imidazole-5-methanol monopotassium salt.
Its molecular formula is C22H22ClKN6O, and its structural formula is:
Losartan potassium, USP is white to off-white powder with a molecular weight of 461.01. It is freely soluble in water; soluble in isopropyl alcohol; slightly soluble in acetonitrile. Oxidation of the 5-hydroxymethyl group on the imidazole ring results in the active metabolite of losartan.
Losartan potassium tablets, USP 25 mg, 50 mg and 100 mg contain potassium in the following amounts: 2.12 mg (0.054 mEq), 4.24 mg (0.108 mEq) and 8.48 mg (0.216 mEq), respectively.
Each losartan potassium tablet, USP intended for oral administration contains 25 mg or 50 mg or 100 mg of losartan potassium. In addition, each tablet contains the following inactive ingredients: colloidal silica anhydrous, hydroxypropyl cellulose (low substituted), hypromellose, lactose monohydrate, magnesium stearate, maize starch (corn starch), microcrystalline cellulose, polyethylene glycol, sodium starch glycolate, talc and titanium dioxide.
12 CLINICAL PHARMACOLOGY
12.1 Mechan |
