losartan

Therapeutic Classification: antihypertensives

Pharmacologic Classification: angiotensin II receptor antagonists

REMS

Hypertension.
Diabetic nephropathy in patients with type 2 diabetes.
Prevention of stroke in patients with hypertension and left ventricular hypertrophy.

Blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II at various receptor sites, including vascular smooth muscle and the adrenal glands.

Therapeutic Effects:

Lowering of BP in hypertensive patients.
Decreased progression of diabetic nephropathy.
Decreased incidence of stroke in patients with hypertension and left ventricular hypertrophy (effect may be less in black patients).

Absorption: Well absorbed but undergoes extensive first-pass hepatic metabolism, resulting in 33% bioavailability.

Distribution: Crosses the placenta.

Protein Binding: 99%.

Metabolism/Excretion: 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; some biliary elimination also occurs.

Half-life: 2 hr (6–9 hr for metabolite).

(antihypertensive effect†)

ROUTE	ONSET	PEAK	DURATION
PO	6 hr	3–6 wks	24 hr

†Onset of antihypertensive effect with chronic dosing.

Contraindicated in:

Hypersensitivity
Bilateral renal artery stenosis
OB: Pregnancy
Lactation: Lactation.

Use Cautiously in:

Volume- or salt-depleted patients or patients receiving high doses of diuretics (correct deficits before initiating therapy or initiate at lower doses)
Black patients (reduction in stroke risk may not apply to this patient population)
Renal impairment due to primary renal disease or heart failure (may worsen renal function)
Hepatic impairment (lower initial doses recommended)
Women of reproductive potential
Pedi: Children <6 yr (safety not established).

CV: chest pain, edema, hypotension.

EENT: nasal congestion.

Endo: hypoglycemia.

F and E: hyperkalemia.

GI: diarrhea, abdominal pain, dyspepsia, nausea.

GU: renal impairment.

Metab: weight gain.

MS: back pain, myalgia.

Neuro: dizziness, fatigue, headache, insomnia, weakness.
Misc: ANGIOEDEMA, fever.

Drug-Drug:

Additive hypotension with other antihypertensives.
Excessive hypotension may occur with concurrent use of diuretics.
↑risk of hyperkalemia with concurrent use of potassium supplements, potassium-containing salt substitutes, or potassium-sparing diuretics.
↑risk of hyperkalemia, renal dysfunction, hypotension, and syncope with concurrent use of ACE inhibitors or aliskiren; avoid concurrent use with aliskiren in patients with diabetes or CCr <60 mL/min; avoid concurrent use with ACE inhibitors
Rifampin may ↓ antihypertensive effects.
NSAIDs and selective COX-2 inhibitors may blunt the antihypertensive effect and ↑ the risk of renal dysfunction.
May increase the effects ofamiodarone, fluoxetine, glimepiride, glipizide, phenytoin, sertraline and warfarin.
May ↑ levels and may ↑ the risk of lithium toxicity.

PO (Adults): Hypertension–50 mg once daily initially (range 25–100 mg/day as a single daily dose or 2 divided doses) (initiate therapy at 25 mg once daily in patients who are receiving diuretics or are volume depleted). Prevention of stroke in patients with hypertension and left ventricular hypertrophy: 50 mg once daily initially; hydrochlorothiazide 12.5 mg once daily should be added and/or dose of losartan ↑ to 100 mg once daily followed by an increase in hydrochlorothiazide to 25 mg once daily based on BP response; Nephropathy in patients with type 2 diabetes–50 mg once daily, may ↑ to 100 mg once daily depending on BP response.
PO (Children 6 yr): Hypertension–0.7 mg/kg once daily (up to 50 mg/day), may be titrated up to 1.4 mg/kg/day (or 100 mg/day).

Renal Impairment

(Children 6 yr): CCr <30 mL/min: Contraindicated.

Hepatic Impairment

PO (Adults): Hypertension–25 mg once daily initially; may be ↑ as tolerated.

(Generic available)

Tablets: 25 mg; 50 mg; 100 mg;
In combination with: hydrochlorothiazide (Hyzaar); see Appendix [not included in this PDA edition]).

Assess BP (lying, sitting, standing) and pulse frequently during initial dose adjustment and periodically during therapy. Notify health care professional of significant changes.
Monitor frequency of prescription refills to determine compliance.
Assess patient for signs of angioedema (dyspnea, facial swelling). May rarely cause angioedema.

Lab Test Considerations:

Monitor renal function. May cause ↑ BUN and serum creatinine.
- May cause ↑ AST, ALT, and serum bilirubin.
- May cause hyperkalemia.
- May cause slight ↓ hemoglobin and hematocrit.

Do not confuse Cozaar with Colace or Zocor.
- Correct volume depletion, if possible, before initiation of therapy.
PO: Administer once daily. For patients with difficulty swallowing tablets, pharmacist can compound an oral suspension; stable for 4 wk if refrigerated. Shake suspension before each use.

Emphasize the importance of continuing to take as directed, even if feeling well. Take missed doses as soon as remembered if not almost time for next dose; do not double doses. Medication controls but does not cure hypertension. Instruct patient to take medication at the same time each day. Warn patient not to discontinue therapy unless directed by health care professional.
Caution patient to avoid salt substitutes containing potassium or foods containing high levels of potassium or sodium unless directed by health care professional. SeeAppendix M.
Caution patient to avoid sudden changes in position to decrease orthostatic hypotension. Use of alcohol, standing for long periods, exercising, and hot weather may increase orthostatic hypotension.
May cause dizziness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
Instruct patient to notify health care professional of medication regimen before treatment or surgery.
Instruct patient to notify health care professional if swelling of face, eyes, lips, or tongue or if difficulty swallowing or breathing occur.
May cause fetal harm. Advise females of reproductive potential to use contraception and notify health care professional if pregnancy is planned or suspected, or if breastfeeding. Losartan should be discontinued as soon as possible when pregnancy is detected. Avoid breastfeeding.
Emphasize the importance of follow-up exams to evaluate effectiveness of medication.
Hypertension: Encourage patient to comply with additional interventions for hypertension (weight reduction, low-sodium diet, discontinuation of smoking, moderation of alcohol consumption, regular exercise, stress management). Medication controls but does not cure hypertension.
- Instruct patient and family on proper technique for monitoring BP. Advise them to check BP at least weekly and to report significant changes.

Decrease in BP without appearance of excessive side effects.
Delayed progression of diabetic nephropathy in patients with type 2 diabetes.
Decreased incidence of stroke in patients with hypertension and left ventricular hypertrophy.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇

Time/Action Profile ⬆ ⬇

Contraind./Precautions ⬆ ⬇

Adv. Reactions/Side Effects ⬆ ⬇

Interactions ⬆ ⬇

Route/Dosage ⬆ ⬇

Availability ⬆ ⬇

Assessment ⬆ ⬇

Implementation ⬆ ⬇

Patient/Family Teaching ⬆ ⬇

Evaluation/Desired Outcomes ⬆ ⬇

US Brand Names ⬆