CV Flashcards
Beta one receptors effect ____ while beta two receptors effect _____
Heart; Lungs
What are the beta adrenergic antagonists MOA
Inhibit symp. stimulation - lowering BP/HR (1) and blocking bronchodilation (2)
If patient taken off beta blocker too quickly, what condition can happen?
Rebound cardiac excitation
Beta blockers are used cautiously in which types of patient population? (Three discussed) Why?
Diabetics because beta two receptors normally inc. glucose levels in blood; therefore blocking causes hypoglycemia
Pt with history of severe allergic reactions b/c epinephrine (treatment) won’t be effective
Pt with COPD (including asthma) b/c beta 2 receptors normally cause bronchodilation if stimulated
Beta blockers are subdivided into 3 groups. Give the distinctions of each generation in regards to the receptor it affects.
1st - affect beta 1 and 2
2nd - cardioselective (beta 1)
3rd - has vasodilating actions (beta 1,2,alpha 1)
If patient HR is under ____ or BP systolic under _____ hold beta blocker
60; 90
Common 1st generation beta blocker
Propanolol
Common 2nd generation beta blocker
Metoprolol
3 beta blockers approved for heart failure
Bisoprolol
Carvedilol
Metoprolol
Common 3rd generation beta blocker
Labetolol - used in HTN crisis
Centrally acting alpha2 agonists MOA
Action: stimulate the alpha2 receptors in the CNS, which decreases sympathetic outflow of the neurotransmitter norepinephrine (NE).
Two common centrally acting alpha 2 agonists
Clonidine
Methyldpoa
Adrenergic Neuron-Blocking agents MOA
Action: inhibit the uptake of NE into storage vesicles resulting in depletion of catecholamines & serotonin from central & peripheral axon terminals.
First line drug class for treating HTN
Diuretics
Name the 4 subclasses of diuretics and where does each work in kidney
Loop - work in loop of henle
thiazide - early distal convoluted tubule
potassium sparing - late distal convoluted tubule & collecting duct
osmotic - proximal convoluted tubule
Loop diuretics MOA
Action/uses: inhibit sodium & water reabsorption in loop of henle - promotes excretion of water, sodium and potassium
Common loop diuretic drug
Furosemide (Lasix)
Which electrolytes to monitor when on diuretic
Mg, K, Na, Cl
How to administer potassium
NEVER give IV push, only IVPG (no more than 10mEq/hr) and IV fluids ( no more than 40mEq/liter) or PO
How to recognize thiazide drug class (suffix) and MOA
-thiazide
promote excretion of sodium, chloride, potassium, and water by decreasing their reabsorption in the distal tubule
Potassium sparing MOA
promote excretion of sodium & water by inhibiting sodium-potassium exchange in the distal tubule
Two subcategories to potassium sparing drug class and common drugs to each
Aldosterone antagonists- Spironolactone
- inhibit action of aldosterone
Non-aldosterone antagonists (works faster and more direct) - Amiloride HCL and triamterene
- fluid which has built up in the tissues of the lungs or body is drawn back into the bloodstream to replace the fluid passed out by the kidneys. This eases symptoms such as edema (pulmonary and extremity)
Osmotic diuretic MOA and drug name
MOA: most of the drug stays in the nephron creating an osmotic force. It inhibits passive reabsorption of water.
Mannitol
Uses of mannitol and unique a/e
Prophylaxis of renal failure
Reduction of increased intracranial pressure (Inc. ICP)
Reduction of intraocular pressure
A/E: edema! watch pt with CHF or pulmonary edema closely