Class: Angiotensin II Receptor Antagonist, Antihypertensive
Dosage Forms. Tablet: 25 mg, 50 mg, 100 mg
Common FDA Label Indication, Dosing, and Titration.
1. Cerebrovascular accident, in hypertensive patients with left ventricular hypertrophy; prophylaxis, diabetic nephropathy: Initial, 50 mg po daily, maintenance 100 mg daily
2. Heart failure: Initial, 12.5 mg po daily, maintenance 50 mg po daily
3. Hypertension: Adults: initial, 50 mg po daily, maintenance 25-100 mg po daily or bid; Children 6 y and older: 0.7 mg/kg po daily, max 50 mg po daily
1. Cardiovascular event risk, reduction: Adults: 50-100 mg po daily
2. Isolated systolic hypertension, left ventricular hypertension, nondiabetic kidney disease: 50 mg po daily
MOA. Losartan is a selective, reversible, competitive antagonist of the angiotensin II receptor (AT1), which is responsible for the physiologic effects of angiotensin II including vasoconstriction, aldosterone secretion, sympathetic outflow, and stimulation of renal sodium reabsorption.
Drug Characteristics: Losartan
Medication Safety Issues: Losartan
Drug Interactions: Losartan
Adverse Reactions: Losartan
Efficacy Monitoring Parameters. Decreased BP.
Toxicity Monitoring Parameters. Signs/symptoms of peripheral edema. Baseline and periodic electrolyte panel, renal function tests, and urine protein are recommended.
Key Patient Counseling Points. Avoid pregnancy. Avoid sudden discontinuation; rebound hypertension can occur. Use potassium supplements or salt substitutes only under medical supervision. May cause dizziness that may worsen if dehydrated. Seek medical attention if angioedema, excessive fluid loss, hyperkalemia, reduction in urination, or jaundice occurs.
Clinical Pearls. Observe patients who are volume depleted for at least 2 h after taking the initial dose and consider a lower starting dose.