Irbesartan

A to Z Drug Facts

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

  Indications Treatment of hypertension; nephropathy in type 2 diabetes.

  Contraindications Standard considerations.

  Route/Dosage

Hypertension

Adults: PO Start with 150 mg once daily; then titrate to 300 mg once daily as necessary.

Children (13 to 16 yr): PO Start with 150 mg once daily; then titrate patients requiring a further reduction in BP to 300 mg once daily.

Children (6 to 12 yr): PO Start with 75 mg once daily; then titrate patients requiring a further reduction in BP to 150 mg once daily.

Nephropathy in Type 2 Diabetes

Adults PO Titrate dose to 300 mg once daily.

Volume- and Salt-Depleted Patients

PO Start with 75 mg.

  Interactions

Lithium:

Plasma concentrations my be increased by irbesartan, resultingin an increase in the pharmacologic and adverse effects of lithium.

  Lab Test Interferences None well documented.

  Adverse Reactions

CARDIOVASCULAR: Chest pain; tachycardia; edema. CNS: Headache; anxiety/nervousness; dizziness. GI: Diarrhea; dyspepsia/heartburn; abdominal pain; nausea/vomiting. RESPIRATORY: Upper respiratory infection; influenza; pharyngitis; rhinitis; sinus abnormality OTHER: Musculoskeletal pain/trauma; fatigue; UIT; rash.

  Precautions

Pregnancy: Category C (first trimester); Category D (second and third trimesters). Can cause injury or death to the fetus if used during second or third trimester. Lactation: Undetermined. CHILDREN: Safety and efficacy not established in children younger than 6 yr. Renal function impairment: Use with caution in patients whose renal function may depend on the activity of the renin-angiotensin-aldosterone system (eg, patients with severe CHF); use may be associated with oliguria, progressive azotemia, acute renal failure, and death. Hypotension: Initiation of antihypertensive therapy may cause symptomatic hypotension in patients with intravascular volume or sodium-depletion.

  Administration/Storage

• Give prescribed dose once daily with or without food.
• Administer alone or in combination with other antihypertensives.
• Do not administer to pregnant women because fetal and neonatal morbidity and death can occur.
• Administer with caution and reduced dosage in patients with possible depletion of intravascular volume or history of hepatic impairment.
• Store tablets at controlled room temperature (59° to 86°F).

  Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note history of anuria, lupus erythematosus, or kidney or liver disease.
• Ensure that serum electrolytes are monitored periodically.
• Monitor and record BP and pulse. Should hypotension result, old medication and notify health care provider.
• Take safety precautionsif orthostatic hypotension occurs.
• Monitor for sighns of hypersensitivity including angioedema involving swelling of the face, lips, eyelids, and tongue. Discontinue medication and notify health care provider immediately if noted.

  Patient/Family Education

• Explain name, dose, action, and potential side effects of drug.
• Advise patient to take prescribed dose once daily, without regard to meals.
• Advise patient to try to take each dose at about the same time each day.
• Inform patient that drug controls, but does not cure, hypertension, and to continue taking drug as prescribed even when BP is not elevated.
• Caution patient not to change the dose or stop taking unless advised by health care provider.
• Instruct patient in BP and pulse measurement skills.
• Advise patient to monitor and record BP and pulse at home and to inform health care provider should abnormal measurements be noted. Also advise patient to take record of BP and pulse to each follow-up visit.
• Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
• Instruct patient to lie or sit down if they experience dizziness or lightheadedness when standing.
• Caution patient that inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to excessive fall in BP, resulting in lightheadedness or fainting.
• Emphasize to hypertensive patient importance of other modalities on BP: weight control, regular exercise, smoking cessation, moderate intake of alohol and salt.
• Advise patient to contact health care provider if pregnant, planning to become pregnant, or breastfeeding.
• Instruct patient to stop taking drug and immediately report any of these symptoms to health care provider: fainting; swelling of the face, lips, eyelids, or tongue.
• Caution patient to not take any prescription or OTC medications, salt substitutes, or dietary supplements unless advised by health care provider.
• Advise patient that follow-up visits and lab tests may be required to monitor therapy and to keep appointments.

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