Valsartan

A to Z Drug Facts

  Action Antagonizes the effect of angiotensin II (vasoconstriction and aldosterone secretion) by blocking the angiotensin II receptor (AT₁ receptor) in vascular smooth muscle and the adrenal gland, producing decreased BP.

  Indications Treatment of hypertension either alone or in combination with other antihypertensive drugs; heart failure.

  Contraindications Standard considerations.

  Route/Dosage

Hypertension

Adults: PO Initial dose : 80 mg qd. Maintenance : 80 to 320 mg qd.

Heart Failure

Adults: PO Initial dose : 40 mg bid; titration to 80 and 160 mg bid should be done to the highest dose, as tolerated by the patient.

  Interactions

Lithium

Plasma concentrations may be increased by valsartan, resulting in an increase in the pharmacologic and adverse effects of lithium.

  Lab Test Interferences None well documented.

  Adverse Reactions

CNS: Headache; dizziness; fatigue. EENT: Sinusitis; pharyngitis; rhinitis. GI: Abdominal pain; diarrhea; nausea. HEMATOLOGIC: Neutropenia. METABOLIC: Hyperkalemia. RESPIRATORY: Cough. OTHER: Fatigue; viral infection; edema; arthralgia.

  Precautions

Pregnancy: Category D (second and third trimester); Category C (first trimester). Lactation: Undetermined. CHILDREN: Safety and efficacy not established. Liver disease: Use with caution. Valsartan is excreted hepatically and higher levels are possible in patients with decreased hepatic function. Renal disease: Decreases in renal function may occur in patients whose renal function is dependent on the renin-angiotensin system; patients with renal artery stenosis may experience acute renal failure. Use caution in treating patients whose renal function may depend on the activity of renin-angiotensin-aldosterone system (eg, severe CHF). Hypotension/Volume-depleted patients: Symptomatic hypotension may occur after initiation of valsartan therapy in patients who are intravascularly volume depleted (eg, those treated with diuretics). Correct these conditions prior to administration of valsartan or start treatment under close medical supervision.

  Administration/Storage

• Administer once daily without regard to food.
• Store at room temperature in tightly closed container. Protect from moisture.
• Can be administered alone or in combination with other antihypertensives.
• Administer with caution and reduced dosage to patients with possible depletion of intravascular volume or a history of hepatic impairment.

  Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Monitor BP and pulse. Should hypotension, tachycardia, or bradycardia result, withhold the medication and notify health care provider.
• Monitor for signs of hypersensitivity including angioedema involving swelling of face, lips, and tongue.
• Ensure that baseline blood and renal function studies have been obtained before administration and monitor during therapy.
• Obtain base BP and pulse and monitor closely for at least 2 hr after initial dose and during first 2 wk of therapy. If systolic BP is less than 90 or if patient has symptoms of hypotension, withhold medication and notify health care provider.
• Monitor for hyperkalemia in patients with impaired renal function or diabetes mellitus and in patients receiving potassium supplements or potassium-sparing diuretics.
• Assist patient with position changes and ambulation during initial phase of therapy. Orthostatic hypotension is common.
• Keep side rails raised if hypotension or dizziness occur.

  Patient/Family Education

• Instruct patient to take medication as prescribed at same time each day.
• Inform patients that valsartan controls but does not cure hypertension.
• Caution patients to take dose exactly as prescribed and not to stop taking medication even if they feel better. Instruct patient not to decrease or increase their dosage.
• Instruct patient not to take OTC medications without consulting health care provider.
• Instruct the patient in BP and pulse measuring skills. Advise patient to call health care provider should abnormal readings occur.
• Instruct patients in methods of fall prevention including arising slowly and sitting on side of bed before standing especially early in therapy.
• Inform patients of importance of adjunct therapies such as dietary planning, a regular exercise program, weight reduction, a low sodium diet, smoking cessation program, alcohol reduction, and stress management.
• Instruct patient to report the following symptoms to health care provider: changes in urinary output, discomfort during urination, weakness, fatigue, dizziness, lightheadedness, jaundice.
• Advise women to contact health care provider if pregnant, planning to become pregnant, or breastfeeding.
• Emphasize importance of follow-up visits and frequent assessment of BP while taking drug.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts