irbesartan
Pharmacologic class: Angiotensin II receptor antagonist
Therapeutic class: Antihypertensive
Pregnancy risk category D
FDA Box Warning
• When used during second or third trimester of pregnancy, drug may cause fetal injury and even death. Discontinue as soon as pregnancy is detected.
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.