losartan potassium

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Related to losartan potassium: lisinopril

losartan potassium


Pharmacologic class: Angiotensin II receptor antagonist

Therapeutic class: Antihypertensive

Pregnancy risk category C (first trimester), D (second and third trimesters)

Pregnancy risk category C (first trimester), D (second and third trimesters)

FDA Box Warning

• When used during second or third trimester of pregnancy, drug may cause fetal harm or death. Discontinue as soon as pregnancy is detected.


Blocks vasoconstricting and aldosterone-secreting effects of angiotensin II at various receptor sites, including vascular smooth muscle and adrenal glands. Also increases urinary flow and enhances excretion of chloride, magnesium, calcium, and phosphate.


Tablets: 25 mg, 50 mg, 100 mg

Indications and dosages


Adults: Initially, 50 mg/day P.O.; range is 25 to 100 mg/day as a single dose or in two divided doses. May be used alone or with other drugs.

Children ages 6 and older: 0.7 mg/kg P.O. daily, up to total of 50 mg

To prevent cerebrovascular accident (stroke) in hypertensive patients with left ventricular hypertrophy (LVH)

Adults: Initially, 50 mg P.O. daily, increased to 100 mg P.O. daily. May be given concurrently with hydrochlorothiazide.

Nephropathy in patients with type 2 diabetes

Adults: 50 mg/day P.O.; increase to 100 mg/day based on blood pressure response.

Dosage adjustment

• Hepatic impairment
• Concurrent diuretic therapy


• Hypersensitivity to drug or its components
• Pregnancy (second and third trimesters)


Use cautiously in:
• heart failure, renal or hepatic impairment, obstructive biliary disorders
• high-dose diuretic therapy
• black patients
• pregnant patients (first trimester) or breastfeeding patients
• children younger than age 6 (safety not established).


• Administer with or without food.
• Know that if drug efficacy (measured at trough) is inadequate with once-daily dosing, prescriber may switch to twice-daily regimen using same or higher daily dosage.
• Be aware that drug may take 3 to 6 weeks to reach maximal efficacy.

Adverse reactions

CNS: dizziness, insomnia, headache, asthenia, fatigue

CV: hypotension

EENT: sinus disorders

GI: nausea, vomiting, diarrhea, dyspepsia, abdominal pain

Metabolic: hyperkalemia

Musculoskeletal: joint pain, back pain, muscle cramps

Respiratory: symptoms of upper respiratory infection, dry cough

Other: hypersensitivity reactions including angioedema


Drug-drug.Diuretics, other antihypertensives: increased risk of hypotension

Fluconazole: inhibited losartan metabolism, increased antihypertensive effects

Indomethacin: decreased losartan effects

Lithium: decreased lithium metabolism

Nonsteroidal anti-inflammatory drugs: decreased renal function

Potassium-sparing diuretics, potassium supplements: hyperkalemia

Rifamycins: enhanced losartan metabolism, decreased antihypertensive effects

Drug-diagnostic tests.Albumin: increased level

Drug-food.Salt substitutes containing potassium: hyperkalemia

Patient monitoring

Watch for angioedema and other hypersensitivity reactions.
• Monitor blood pressure to evaluate drug efficacy.
• Assess liver and kidney function tests and electrolyte levels.
• Stay alert for oliguria, progressive azotemia, and renal failure in patients with severe heart failure whose renal function depends on the renin-angiotensin-aldosterone system.
• Know that in black patients, losartan and other ACE inhibitors may be ineffective when used alone. Drug isn't indicated for stroke prevention in black hypertensive patients with LVH.
• Be aware that drug may cause fetal injury or death when used during second or third trimester of pregnancy.

Patient teaching

• Instruct patient to avoid potassium supplements and salt substitutes containing potassium, unless directed by prescriber.

Caution female patient not to take drug during second or third trimester of pregnancy. Advise her to contact prescriber immediately if she suspects pregnancy.
• Tell female patient to discuss breastfeeding with prescriber before taking.

Instruct patient to immediately report hypersensitivity reactions, especially lip or eyelid swelling, throat tightness, and difficulty breathing.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.

losartan potassium

(lōsär´tan pətas´ēəm),
n brand name: Cozaar;
drug class: angiotensin II receptor antagonist;
action: blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II;
use: hypertension, as a single drug or in combination with other antihypertensives.
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References in periodicals archive ?
Losartan potassium has been shown to produce adverse effects in rat fetuses and neonates, including decreased body weight, delayed physical and behavioral development, mortality and renal toxicity.
Losartan potassium was not carcinogenic when administered at maximally tolerated dosages to rats and mice for 105 and 92 weeks, respectively.
Losartan potassium was negative in the microbial mutagenesis and V-79 mammalian cell mutagenesis assays and in the in vitro alkaline elution and in vitro and in vivo chromosomal aberration assays.
Fertility and reproductive performance were not affected in studies with male rats given oral doses of losartan potassium up to approximately 150 mg/kg/day.
In double-blind clinical trials of various doses of losartan potassium and hydrochlorothiazide, the incidence of hypertensive patients who developed hypokalemia (serum potassium <3.
These dosages have been shown to provide respective systemic exposures (AUCs) for losartan, its active metabolite and hydrochlorothiazide that are approximately 60, 60 and 30 times greater than those achieved in humans with 100 mg of losartan potassium in combination with 25 mg of hydrochlorothiazide.
See CLINICAL PHARMACOLOGY, Pharmacodynamics and Clinical Effects; Losartan Potassium, Reduction in the Risk of Stroke.
Adverse experiences have been limited to those that were reported previously with losartan potassium and/or hydrochlorothiazide.
Each tablet contains 100 mg of losartan potassium and 25 mg of hydrochlorothiazide.
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.