ACEI and ARBs

ACEI and ARBs

• ACEI and ARBs are used in the treatment of hypertension with concomitant illnesses.
• Used in the treatment of heart failure, myocardial infarction, and diabetic nephropathy.

ACEI

ACEI work by blocking the enzyme that cleaves angiotension I to form the vasoconstrictor angiotension II. Because of this, there is a reduction in aldosterone. Decreased aldosterone results in less water absorption and sodium/potassium exchange in the distal renal tubule causing a slight increase in serum potassium. ACEIs also inhibit breakdown of bradykinin (Vasodilator) by blocking the enzyme kinase II. This increase in bradykinin causes a dry cough in some patients. The use of ACE inhibitors significantly reduces morbidity and mortality in heart failure patients.

Side effects of ACEI

• First dose hypotension (particularly in patients taking diuretics)
• Dry cough (most frequent symptom)
• Angioedema (most serious)
• Hyperkalemia (monitor potassium)
• Acute renal failure (occurs in bilateral renal artery stenosis)
• Fetal injury (contraindication in pregnancy)

ACEI drugs (ends in “pril”)

• Captopril capoten
• Enalapril vasotec
• Fasinopril monopril
• Lisinopril prinivil, zestril
• Quinapril accupril
• Ramipril altace

Copy of Ace Inhibitors

Treatment Principles of ACEI and ARBS

• ACEIs and ARBs have a low incidence of adverse reactions
• All ACEIs and ARBs have similar therapeutic action and adverse reactions
• Lower dose may be needed in patients with renal or hepatic insufficiency
• Useful in elderly
• Less effective in blacks when used as monotherapy
• ACEIs and ARBs are associated with significant fetal risk
• Do not use and ACEI and ARB together (use one or the other)

How to monitor ACEI and ARB: (baseline and periodic)

• Electrolyte panel
• Serum blood urea nitrogen and creatinine
• UA
• WBC
• Once stable: Recheck serum creatinine and potassium at 2 and 4 weeks
• No risk factors for renal deterioration: Recheck every 3 to 6 months

ACEI and ARBs should be avoided in patients with

• Renal failure
• Hypotension (sys BP <90 to 100 mm Hg or 30 mm Hg below baseline)
• Shock
• H/O bilateral renal artery stenosis
• Prior worsening of renal function with ACEIs
• Pregnancy

ARBs

Angiotension receptor blockers (ARBs) are potent competitive antagonists of the angiotension type 1 receptor. ARBs do not affect bradykinin levels and do not cause a dry cough. ARBs are as effective in lowering blood pressure as ACE inhibitors and are equally renal and cardiovascular protective, with fewer side effects. ARBs are a substitute for ACE inhibitors in patients that cannot tolerate the latter.

Side effects of ARBs

• ARBs have adverse effect profile similar to that of ACEI (except cough)
• First dose hypotension (particularly in patients taking diuretics)
• Angioedema (most serious)
• Hyperkalemia (monitor potassium)
• Acute renal failure (occurs in bilateral renal artery stenosis)
• Fetal injury (contraindication in pregnancy)

ARBs drugs (ends in “artan”)

• Candesartan atacand
• Losartan cozaar
• Telmisartan micardis
• Valsartan diovan

JNC8 Guidelines for ACEI/ARBs

• Non-black patients with hypertension, initial treatment can be a thiazide type diuretic, CCB, ACE inhibitor, or ARB
• In the general black population, including those with DM, initial therapy should be a thiazide type diuretic or CCB
• In patients >18 years of age with CKD, initial or add on therapy should be and an ACE inhibitor are ARB, regardless of race or diabetes status
• Do not use and an ACEI and ARB together in the same patient
• If goal blood pressure is not reached within a month of treatment, increase the dose of the initial drug or add a second drug (CCB, ACEI, or ARB)

Angiotensin II Receptor Antagonist (ARB) Chart

Key Notes For ACEI

• ACE inhibitors inhibit breakdown of bradykinin and decrease the secretion of aldosterone, resulting in decreased sodium and water retention
• BP is lowered, and this is not accompanied by changes in HR
• Renal perfusion is increased
• Renal vascular resistance is decreased
• Prevent ventricular remodeling and improve endothelial (inflammation) function after MI

Key Notes for ARBs

• ARBs block effects of angiotensin II by blocking the binding of angiotensin II to its receptors
• ARBs are more active against AT1 receptors
• ARB use in HF may be as effective as or slightly less effective than ACEIs
• No dry cough
• Decreased incidence of angioedema

References

Edmunds, M. W., & Mayhew, M. S. (2014). Pharmacology for the primary care provider (4th ed.). St.   Louis, MO: Elsevier Mosby.

Harvey, R. A., Clark, M. A., Finkel, R., Rey, J. A., & Whalen, K. (2012). Pharmacology (5th ed.). Baltimore, MD: Lippincott.

JNC8 Guidlines 2014. (2014). JNC 8 Guidlines. Retreived from:

 http://jama.jamanetwork.com/article.aspx.articleid=1791497