Cardiac Drugs Flashcards
Drugs acting on the Renin-Angiotensin-Aldosterone System
-Angiotensin-converting enzyme inhibitors (ACE inhibitors)
-Angiotensin II receptor blockers (ARB)
-Direct Renin Inhibitors
-Aldosterone inhibitors
RAAS System
-Plays an important role in regulating blood pressure, blood volume, and fluid & electrolyte balance.
-Mediates certain pathophysiologic changes associated with HTN, heart failure and MI.
Angiotensin
-Precursor of Angiotensin II.
-Weak biological activity.
Angiotensin II
-Participates in all processes regulated by the RAAS.
-Prominent actions are vasoconstriction and stimulation of aldosterone.
-Raises blood pressure.
-Can act on the heart and cause pathologic changes in their structure and function.
-Vasoconstriction caused by Angiotensin II
-Acts directly on vascular smooth muscle to cause constriction.
-Prominent in arterioles and less so on veins.
Aldosterone
-Released from the adrenal cortex.
-Acts on distal tubules of the kidney to cause retention of sodium and excretion of potassium and hydrogen.
-Since sodium is retained so is water which increases blood volume.
-Regulates blood volume and blood pressure.
Angiotensin II
-Formed by renin and angiotensin-converting enzyme (ACE)
-More potent than angiotensin 1
Renin
-catalyzes the formation of angiotensin I from angiotensinogen.
-Produced from the juxtaglomerular cells of the kidney and undergoes controlled release into the bloodstream.
Angiotensin-converting enzyme
-Located on blood vessel surfaces and vasculature of the lungs.
-catalyzes the conversion of angiotensin I to angiotensin II.
Renin-angiotensin-aldosterone-system
-Helps regulate blood pressure in the presence of hemorrhage, dehydration, or sodium depletion.
Two basic processes of the RAAS raising blood pressure:
Acting through angiotensin II
1. Vasoconstriction
2. Renal retention of water and sodium
Angiotensin II acts in two ways in two ways to promote renal retention of water.
-Constricts renal blood vessels, angiotensin II reduces renal blood flow and thereby reduces glomerular filtration.
-Angiotensin II stimulates the release of aldosterone from the adrenal cortex. Aldosterone acts on the renal tubules to promote retention of sodium and water and the excretion of potassium.
ACE Inhibitors
-Used for treating hypertension, heart failure, diabetic neuropathy, and MI.
-Decrease levels of angiotensin II being produced.
-Increase levels of bradykinin (through inhibition of kinase II)
ACE Inhibitors
-Dilate blood vessels (primarily at the arterioles, and to a lesser extent veins)
-reduce blood volume through effects of the kidneys
-prevent or reverse pathologic changes in the heart and blood vessels mediated by angiotensin II and aldosterone.
-Can cause hyperkalemia
ACE inhibitors
-Increase bradykinin causes vasodilation.
-Given after an MI
-Drugs end in -pril
ACE inhibitor therapeutic uses
-Hypertension
-Heart failure
-Myocardial infarction-stops further deuteriation of vessels
-Diabetic and nondiabetic neuropathy
-Prevention of stroke, MI, and death of patients at high cardiovascular risk.
ACE inhibitors adverse effects
-First dose hypotension- risk for fall. Dizziness
-Fetal injury
-Cough caused by accumulation of bradykinin secondary to inhibition of kinase II.
-Angioedema- swelling in face. Stop immediately and do not take again.
-Hyperkalemia- interrupts normal process and holds onto potassium
-Dysgeusia (change in taste) and rash
-Renal failure- contraindicated for people with kidney issues. Bilateral renal artery stenosis.
-Neutropenia- associated with captopril
-Do not give to pregnant women
ACE inhibitors drug interactions
-Diuretics- may cause electrolyte issues.
-Antihypertensive agents
-Drugs that raise potassium levels- ACE inhibitors are potassium sparing.
-Lithium- can cause lithium to accumulate to toxic levels
-NSAIDS- may reduce antihypertensive effects
ACE inhibitor administration
-Administered orally, except enalapril can be given IV.
-Captopril (capoten) and Moexipril need to be administered with food.
ACE inhibitor drugs
Benazepril (Lotensin)
-Hypertension
Captopril (Capoten)
-Hypertension
-Heart failure
-LVD after MI
-Diabetic neuropathy
-Needs to be given one hour before meals
Enalapril (Vasotec)
-Hypertension
-Heart failure
-Asymptomatic LVD
-Can be given IV
Fosinopril
-Hypertension
-Heart failure