ARBs
ARBs
ARBs selectively block the binding of angio tensin II to specific tissue receptors found in the vascular smooth muscle and adrenal gland. This action blocks the vasoconstric tion effect of the reninangiotensin system as well as the release of aldosterone leading to decreased BP; may block vessel remodel ing that occurs in hypertension and con tributes to the development of atherosclero sis.
Indications
Treatment of hypertension, alone or in com bination with other antihypertensives Nephropathy in type 2 diabetes (losartan, irbesartan) Treatment of heart failure in patients re sistant to ACE inhibitors (valsartan) Reduction in the risk of stroke in patients with hypertension and left ventricular hy pertrophy (losartan) Contraindications and cautions
Contraindicated with hypersensitivity to any ARB, pregnancy (use during the second or third trimester can cause injury or even death to the fetus), lactation. Use cautiously with renal impairment, hypo volemia. Adverse effects
CNS: Headache, dizziness, syncope, mus cle weakness, fatigue, depression CV: Hypotension Dermatologic: Rash, inflammation, ur ticaria, pruritus, alopecia, dry skin GI: Diarrhea, abdominal pain, nausea, constipation Respiratory: URI symptoms,cough, si nus disorders Other: Cancer in preclinical studies, UTIs, pain Interactions
Drugdrug Decreased effectiveness if com bined with phenobarbital Risk of increased lithium levels Risk of hyperkalemia if com bined with potassiumsparing diurectics, potas sium supplements, salt substitutes, aliskiren Nursing considerations
Assessment
History: Hypersensitivity to any ARB, preg nancy, lactation, renal impairment, hypo volemia Physical: Skin lesions, turgor; body T; re flexes, affect; BP; R, respiratory ausculta tion; renal function tests Interventions
Administer without regard to meals. Black box
warning Ensure that pa tient is not pregnant before beginning therapy; suggest the use of barrier contraception; fetal injury and deaths have been reported. Find an alternative method of feeding in fant if ARBs are given to a nursing mother. Depression of the reninangiotensin system in infants is potentially very dangerous. Alert surgeon and mark on patient’s chart that an ARB is being taken. The blockage of the reninangiotensin system after surgery can produce problems. Hypotension may be reversed with volume expansion. If BP control does not reach desired levels, diuretics or other antihypertensives may be added to the drug regimen. Monitor patient’s BP carefully. Monitor patient closely in situations that may cause a decrease in BP secondary to re duction in fluid volume—excessive perspi ration, dehydration, vomiting, diarrhea— excessive hypotension can occur. Angiotensin II Receptor Blockers (ARBs) 20 ? Angiotensin II Receptor Blockers (ARBs) Adverse effects
in italics are most common; those in bold are lifethreatening. U Do not crush. Teaching points
Take these drugs without regard to meals. Do not stop taking these drugs without con sulting your health care provider. Use a barrier method of birth control while using these drugs; if you become pregnant or desire to become pregnant, consult your physician. You may experience these side effects: Dizzi ness (avoid driving a car or performing haz ardous tasks); nausea, abdominal pain (proper nutrition is important; consult a di etitian to maintain nutrition); symptoms of upper respiratory tract or urinary tract in fection, cough (do not selfmedicate, con sult your health care provider if this becomes uncomfortable). Report fever, chills, dizziness, pregnancy. Representative drugs
azilsartan candesartan eprosartan irbesartan losartan olmesartan telmisartan valsartan
