irbesartan

Action

Blocks aldosterone-secreting and potent vasoconstrictive effects of angiotensin II at tissue receptor sites, which reduces vasoconstriction and lowers blood pressure

Availability

Tablets: 75 mg, 150 mg, 300 mg

Indications and dosages

➣ Hypertension

Adults: 150 mg/day P.O.; may increase to 300 mg/day

➣ Nephropathy in patients with type 2 diabetes and hypertension

Adults: 300 mg P.O. once daily

Dosage adjustment

• Volume-depleted or hemodialysis patients receiving diuretics

Contraindications

• Hypersensitivity to drug or its components

Precautions

Use cautiously in:

• heart failure, volume or sodium depletion, renal disease, hepatic impairment

• black patients

• females of childbearing age

• pregnant or breastfeeding patients

• children ages 18 and younger (safety not established).

Administration

• Administer with or without food.

• Know that drug may be given with other antihypertensive drugs.

Adverse reactions

CNS: dizziness, fatigue, headache, syncope

CV: orthostatic hypotension, chest pain, peripheral edema

EENT: conjunctivitis, vision disturbance, ear pain, sinus disorders

GI: nausea, diarrhea, constipation, abdominal pain, dry mouth

GU: albuminuria, renal failure

Metabolic: gout, hyperkalemia

Musculoskeletal: joint pain, back pain, muscle weakness

Respiratory: upper respiratory tract infection, cough, bronchitis

Other: dental pain

Interactions

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

Lithium: increased lithium blood level

Nonsteroidal anti-inflammatory drugs: decreased antihypertensive effects

Potassium-sparing diuretics, potassium supplements: increased risk of hyperkalemia

Drug-diagnostic tests. Albumin: increased level

Drug-food. Salt substitutes containing potassium: increased risk of hyperkalemia

Patient monitoring

• Monitor vital signs, especially blood pressure.

• Watch for signs and symptoms of orthostatic hypotension.

• Watch blood pressure closely when volume depletion may cause hypotension (as in diaphoresis, nausea, vomiting, diarrhea, and postoperative period).

• Assess fluid intake and output. Keep patient well hydrated, especially if he's receiving diuretics concurrently.

• Monitor blood urea nitrogen and creatinine levels.

Patient teaching

• Tell patient he may take with or without food.

• Instruct patient to change position slowly and to stay well hydrated, to minimize blood pressure decrease when rising.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Tell female patient that drug has been linked to fetal injury and deaths. Caution her not to get pregnant during therapy. Advise her to use barrier contraception.

• Instruct female patient to report pregnancy.

• Instruct patient to report fever, chills, dizziness, severe vomiting, diarrhea, and dehydration.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.