Other
WARNING: FETAL TOXICITY
- When pregnancy is detected, discontinue losartan potassium as soon as possible.
- Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus. See WARNINGS, Fetal Toxicity.
Losartan potassium is an angiotensin II receptor (type AT1) antagonist. 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.
Each losartan potassium tablet 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.
Losartan potassium 25 mg, 50 mg and 100 mg tablets 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.
Losartan potassium tablets are contraindicated in patients who are hypersensitive to any component of this product.
Do not co-administer aliskiren with losartan potassium tablets in patients with diabetes.
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.
Adult Hypertensive Patients:
Losartan potassium tablets may be administered with other antihypertensive agents, and with or without food.
Dosing must be individualized. The usual starting dose of losartan potassium tablets is 50 mg once daily, with 25 mg used in patients with possible depletion of intravascular volume (e.g., patients treated with diuretics) (see WARNINGS, Hypotension — Volume-Depleted Patients) and patients with a history of hepatic impairment (see PRECAUTIONS, General). Losartan potassium tablets can be administered once or twice daily with total daily doses ranging from 25 mg to 100 mg.
If the antihypertensive effect measured at trough using once-a-day dosing is inadequate, a twice-a-day regimen at the same total daily dose or an increase in dose may give a more satisfactory response. The effect of losartan is substantially present within one week but in some studies the maximal effect occurred in 3 to 6 weeks (see CLINICAL PHARMACOLOGY, Pharmacodynamics and Clinical Effects, Hypertension).
If blood pressure is not controlled by losartan potassium tablets alone, a low dose of a diuretic may be added. Hydrochlorothiazide has been shown to have an additive effect (see CLINICAL PHARMACOLOGY, Pharmacodynamics and Clinical Effects, Hypertension).
No initial dosage adjustment is necessary for elderly patients or for patients with renal impairment, including patients on dialysis.
Pediatric Hypertensive patient ≥ 6 years of age:
The usual recommended starting dose is 0.7 mg/kg once daily (up to 50 mg total) administered as a tablet or a suspension (see Preparation of Suspension). Dosage should be adjusted according to blood pressure response. Doses above 1.4 mg/kg (or in excess of 100 mg) daily have not been studied in pediatric patients (see CLINICAL PHARMACOLOGY, Pharmacokinetics,Special Populationsand Pharmacodynamics and Clinical Effectsand WARNINGS, Hypotension — Volume-Depleted Patients,).
Losartan potassium tablets are not recommended in pediatric patients <6 years of age or in pediatric patients with glomerular filtration rate <30 mL/min/1.73 m2 (see CLINICAL PHARMACOLOGY, Pharmacokinetics,Special Populations, Pharmacodynamics and Clinical Effects, and PRECAUTIONS).
Losartan Potassium Tablets USP, 50 mg are white to off-white, capsule-shaped, film-coated tablets debossed with the logo of "Z16" on one side and lip type breakline on other side and are supplied as follows:
NDC 63187-071-30 in bottle of 30 tablets
NDC 63187-071-60 in bottle of 60 tablets
NDC 63187-071-90 in bottle of 90 tablets
Losartan Potassium Tablets USP, 100 mg are white to off-white, capsule-shaped, film-coated tablets debossed with the logo of "Z18" on one side and plain on other side and are supplied as follows:
NDC 63187-072-30 in bottle of 30 tablets
NDC 63187-072-60 in bottle of 60 tablets
NDC 63187-072-90 in bottle of 90 tablets