Week 6 power points Flashcards
Four Factors That Affect Cardiac Performance
Preload
Afterload
Heart Rate
Contractility
Cardiac Output
Volume of blood flowing through either the systemic or the pulmonary circuit per minute = L/min
HR x SV = CO
Normal = 5L/min
Coronary Artery Disease (CAD)
- Progressive growth of atheromatous plaques, in the coronary arteries
- Injure the endothelial lining of the artery, causing an inflammatory reaction.
- Triggers development of larger plaques containing foam cells, platelets, fribrin, fats, that collect on the vessel lining.
- Limits blood flow.
- These plaques can rupture.
- Increased incidence among people with high serum lipid levels
Unmodifiable Risk Factors for CAD
Genetic predisposition
Age
Gender
Modifiable Risk Factors for CAD
Gout Cigarette smoking Sedentary lifestyle High stress levels Hypertension Obesity Diabetes Untreated bacterial infections Treatment with tetracycline
CAD Treatment
Decrease dietary fats Losing weight Eliminating smoking Increase exercise Decrease stress Treat hypertension Treat diabetes Treat gout
Lipoproteins Produced in the Liver
1) Low-density lipoproteins (LDL): Enter circulation as tightly packed cholesterol, triglycerides, and lipids.
Carried by proteins that enter circulation; broken down for energy or stored for future use as energy.
VLDL are turned into LDL
2) High-density lipoproteins (HDL): Enter circulation as loosely packed lipids.
Used for energy; pick up remnants of fats and cholesterol left in the periphery by LDL breakdown
Causes of Hyperlipidemia
- Excessive dietary intake of fats
- Genetic alterations in fat metabolism leading to a variety of elevated fats in the blood
- Hypercholesterolemia, hypertriglyceridemia, and alterations in LDL and HDL concentrations
Action of antihyperlipidemic agents
- Lower serum levels of cholesterol and lipids
- Prevention of CAD
Drugs Used to Treat Hyperlipidemia
- HMG-CoA inhibitors
- Bile acid resins or sequestrants
- Fibric Acid Agents
- Niacin
HMG-CoA Reductase Inhibitors “Statins” Indications
Example: Atorvastatin (Lipitor)
- Adjuncts with diet and exercise for the treatment of increased cholesterol and LDL levels that are unresponsive to dietary restrictions alone
- Slow progression of CAD
- Prevent first MI
HMG-CoA Reductase Inhibitors “Statins” Actions
- Inhibit HMG-CoA, decrease serum cholesterol levels, LDLs, and triglycerides, and increase HDL levels
HMG-CoA Reductase Inhibitors “Statins” assessment and teaching
- Undergo first-pass metabolism by the liver
- Assess Liver function and caution in persons with active liver disease or history of alcoholism
- Assess for pregnancy and lactation
- Take at night
- Can cause GI symptoms
- Monitor for muscle pain or tremors
- Rhabdomyolysis
HMG-CoA Reductase Inhibitors “Statins” Interactions
- Macrolides (Erythromycin), “Azoles”, Fibric Acid Agents (Gemfibrozil), Immunosuppresants (cyclosporine), and niacin
- Digoxin and warfarin
- Grapefruit juice
HMG-CoA Reductase: Lovastatin (Mevacor)
Older, Higher risk of rhabdomyolysis
HMG-CoA Reductase: Simvastatin (Zocor)
- Less liver toxicity
- Prevents MIs
- 10-17 yo. OK
HMG-CoA Reductase: Pravastatin (Pravachol)
- Effective at deceasing CAD, MI
- Children 8 and up
A patient is taking a HMG-CoA reductase inhibitor. Which of the following tests should be performed at the start of therapy and periodically after?
Liver function
Electrolyte levels
Complete blood count
ECG
Liver function
-Due to the fact that increased liver can occur in those receiving long term HMG-CoA therapy
Bile Acid Resins indications
Example: Cholestyramine (Questran)
-Reduce elevated serum cholesterol in patients with primary hypercholesterolemia
allow excretion in feces instead of reabsorption, and cause serum cholesterol levels to fall
Bile Acid Resins assessment and teaching
- Not absorbed systemically, Excreted in the feces
- Assess for pregnancy or lactation
- Can cause bloating and constipation
- Mix powder with water
- Colesevelam (Welchol)- taken as a tab and less frequently than the prototype
Bile Acid Resins Pharmacokinetics
Not absorbed systemically b/c excreted in the feces.
Bile Acid Resins contraindications
- Allergy
- Complete biliary obstruction: which would prevent bile from being secreted into the intestine
- Abnormal intestinal function: could be aggravated by the presence of these drugs
- Pregnancy and lactation: potential decrease in the absorption of fat and fat-soluable vitamins could have a detrimental effect on the fetus or neonate
Bile Acid Resins interactions
- Can be used concurrently with Statins
- Malabsorption of fat-soluble vitamins
- Thiazide diuretics, digoxin, warfarin, thyroid hormones, and corticosteroids- and lots others….
- Do not take with other medications (1 hour after or 4 hours before) these drugs have delayed absorption when taken with BAS
Bile Acid Resins adverse effects
- Headache, fatigue, and drowsiness
- Direct GI irritation: nausea and constipation
- Could lead to fecal impaction and aggravation of hemorrhoids
- Increased bleeding times
- decreased absorption of
- Vitamin K and subsequent decreased production of clotting factors
- Vitamin A and E deficiencies
- decreased absorption of fat-soluble vitamins, causes rash and muscle pain
Fibric Acid Agents
- Example: Gemfibrozil (Lopid)
- Inhibits peripheral breakdown of lipids
- Reduces production of triglycerides and LDL and Increases HDL
- Can cause GI and muscle discomfort
- Monitor for Gallstones
- DO NOT combine with Statins
- Gemfibrozil (Lopid)
- Type of fibrate: decrease in lipoprotein and triglyceride synthesis and secretion.
- Do not combine with statins = increased risk of rhabdo.
Niacin (vitamin B3)
- Vitamin B3, inhibits release of free fatty acids from adipose tissue
- Much higher doses than typically Vitamin replacement
- Should be done under the supervision of a physician
- Increases rate of triglyceride removal from plasma
Niacin (Vitamin B3) side effects
- Severe cutaneous flushing and hot flashes
- Nausea & abdominal pain
- Increase in uric acid
- increased uric acid (gout)
- Nicotinic acid: Increases rate of triglyceride removal from plasma and generally reduces LDL and triglyceride levels and increases HDL levels.
- Initial effect within 5-7 days with maximum effect in 3-5 weeks
Lipid lowering agent: Ezetimibe (Zetia) indication
- When combined with a statin it is called Vytorin
- Purpose
- Decease serum cholesterol levels.
- May be used with diet/exercise, Statins, or Bile Acid Resins
Lipid lowering agent: Ezetimibe (Zetia) assessment and teaching
- Monitor for pregnancy
- Most common side effects are GI, however CNS changes can also occur
Cardiovascular Disease (CVD)
- Includes conditions of heart and blood vessels
- Hypertension is most common form of CVD
- Most frequent causes of death in U.S
- Prehypertension (120-139/80-89) affects approximately 22% of the adult population
- High blood pressure affect 1 in 4 Americans
- Diabetics are 2-3 times more likely to have hypertension than nondiabetics
- African Americans have the highest rate (33%)
- Among people with HTN, more than 32% do not realize they have the disease –”silent killer”
Elements Determining Blood Pressure
- Heart rate
- Stroke volume: Amount of blood that is pumped out of the ventricle with each heartbeat
- Total peripheral resistance: Resistance of the muscular arteries to the blood being pumped through them
Physiological Regulation of Blood Pressure
1) Central and autonomic nervous systems
- Vasomotor center
- Baroreceptors
- Chemoreceptors
2) Emotions affect blood pressure
- Stress and anger increase
- Depression and lethargy decrease
Endocrine System
- Regulates blood pressure
- Natural hormones affect blood pressure daily
- Epinephrine and norepinephrine injections raise B/P
- Antidiuretic hormone raises B/P by raising blood volume
Bloop pressure lifestyle and genetic factors
1) Lifestyle
- Exercise or activity regimen
- Use of medication
- Dietary habits
2) Genetic
- Race
- Gender
- Family history of hypertension
- Estimated that 20% of the people in the US have hypertension and many are unaware.
- 90% have essential hypertension: hypertension with no known cause. [Secondary HTN = pheochromocytoma, tumor in the adrenal gland]
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Risks for Coronary Artery Disease Related to Hypertension
- Thickening of the heart muscle
- Increased pressure generated by the muscle on contraction
- Increased workload on the heart
Stepped Care Approach to Treating Hypertension
-Because an underlying cause of hypertension is usually unknown, treatment is aimed at altering the body’s ability to regulate BP.
Step 1: lifestyle modifications are instituted (weight reduction, smoking cessation, reduce alcohol and salt in the diet, also increase exercise)
Step 2: drug therapy is added if the measures in step 1 are insufficient. May start with a diuretic, Beta blocker, ACE inhibitor or ARB, or CA++ channel blocker.
Step 3: drug dose or class may be changed or another drug added if the patient’s response is inadequate
Step 4: includes all of the above measures with the addition of more antihypertensive agents until blood pressure is controlled
Types of Drugs Used to Control Blood Pressure
1) Diuretic
2) Beta-blocker
3) ACE inhibitor
4) Calcium channel blocker
Diuretics
- Drugs that increase the excretion of sodium and water from the kidney.
- Often 1st HTN treatment agents
1) Thiazide Diuretics: Chlorothiazide, Hydrochlorothiazide
2) Loop Diuretics: Furosemide, Bumetanide(Bumex)
3) Carbonic anhydrase inhibitors: Acetazolamide(Diamox)
4) Potassium-Sparing Diuretics: spironolactone, triamterene
Diuretics Mechanism of action Primary use Adverse effects Example drugs
- Mechanism of action: increase amount of urine produced and excreted
- Primary use: for mild to moderate hypertension
- Adverse effects: electrolyte imbalances, especially loss of potassium
Example drugs: hydrochlorothiazide (HydroDiuril), furosemide (Lasix)
Calcium Channel Blocker indication
- Example: Nifedipine (Procardia, Adalat)
- Treatment of essential hypertension in the extended release form
- Because of all of actions Ca++ Channel Blockers it is used for HTN, Antiarrhythmic and antianginal
Calcium Channel Blocker action
Inhibits movement of calcium ions across the membranes of cardiac and arterial muscle cells, depressing the impulse and leading to slowed conduction, decreased myocardial contractility, and dilation of arterioles
Ca++ channel blockers prevent the movement of calcium into the cardiac and smooth muscle cells when the cells are stimulated. This block interferes with?
the muscle cell’s ability to contract => loss of smooth muscle tone, vasodilation, and decreased in peripheral resistance. This decreases BP, cardiac workload, and myocardial oxygen consumption.
Calcium Channel Blocker Assessment and teaching
-Monitor for heart block or sick sinus syndrome
-Not used in pregnancy or lactation
-Monitor vitals
-Can cause nausea
-Monitor for peripheral edema
-Avoid Grapefruit juice- increases absorption
-Drug-to-drug interaction
Cyclosporine
most Ca++ channel blockers end in?
DIPINE (exceptions: Diltiazem and Verapamil)
Calcium channel blockers: Amlodipine (Norvasc)
- Not sustained release
- Oral used alone or in combo w/other agents to treat HTN
- Also used for angina
- does not have to be an extended release form. -
Calcium channel blockers: Felodipine (Plendil):
used for HTN in adults, NOT used for angina
Calcium channel blockers: Nifedipine (Procardia XL)
sustained release for the treatment of HTN
Calcium channel blockers: Verapamil (Calan SR)
Verapamil (Calan SR)
Sustained release used for HTN
Affects both cardiac and periphery
ACE Inhibitors Indications
Treatment of hypertension, CHF, diabetic nephropathy, and left ventricular dysfunction following an MI
Example: Enalapril (Vasotec)
ACE Inhibitors action
Block ACE from converting angiotensin I to angiotensin II, leading to a decrease in blood pressure, a decrease in aldosterone production, and a small increase in serum potassium levels along with sodium and fluid loss
- Action: Increase in K+, Na+ and fluid LOSS!!!!
Example: Enalapril (Vasotec)
ACE Inhibitors Assessment and Teaching
- Can cause GI irritation
- Monitor Closely for Angioedema
- Can cause a dry, annoying, cough
- Caution in patients with CHF
- Take first dose at bedtime
- Monitor potassium level as hyperkalemia can occur
ACE Inhibitors drug-drug interaction
Allopurinol
ACE Inhibitors contraindications
known to cross the placenta and have serious fetal abnormalities. Several ACE inhibitors have been detected in breast milk.
Caution in CHF :
Benazepril (Lotensin) Adverse effects
HTN
**Cough