Pharmacology Exam 2

Consequences of High BP

• stroke

• HF

• sexual dysfunction

• heart attack

• vision loss

• kidney disease/failure

Stages of HTN

Normal: <120 / <80

Elevated: 120-129 / <80

Stage 1: 120-139 / 80-89

Stage 2: 140 / 90

2 Main Factors in HTN

• cardiac output

• peripheral resistance

Determinants of BP

• cardiac output (systolic)

• systemic vascular resistance (diastolic)

Cardiac Output Formula

HR x SV

(heart rate times stroke volume)

Cardiac Output

total amount of blood ejected by one of the ventricles in L/min

Cardiac Output Normal Value

4 - 6 L

Stroke Volume

• amount of blood ejected from one of the ventricles per beat

• impacted by preload, afterload, contractility

Stroke Volume Normal Value

60 to 130 L

Preload

amount of blood in the left ventricle at the end of diastole

Afterload

resistance to ejection of blood from the ventricle

Systemic Vascular Resistance

the resistance of the systemic BP to left ventricular ejection

Contractility

• force generated by the myocardium

• enhancers: sympathetic activity + some meds (digoxin, dopamine or dobutamine)

• depressors: hypoxemia, acidosis + certain meds (beta blockers)

Kidney BP Regulation

• control of fluid volume

• RAAS

BV BP Regulation

• vasoconstriction

• vasodilation

• injury to endothelial lining

Beta 1 Receptors

in cardiac tissue, stimulate increased cardiac activity & HR

Beta 2 Receptors

in smooth vessels in muscle in blood cells, in bronchi, periphery and uterine muscle

Beta 3

in kidneys to help stimulate RAAS

Renin-Angiotensin System

1. Decreased pressure causes renin secretions from kidney

2. Liver produces angiotensinogen

3. Angiotensinogen to angiotensin I then angiotensin 2

4. Angiotensin 2 triggered aldosterone

5. Aldosterone causes increase NA and K reabsorption
   
   Final cause: higher BV, sodium and water

Hypotension Response

• SNS stimulation

• secretion of adrenal medulla by epinephrine and norepinephrien

• formation of angiotensin II and aldosterone

• kidneys retain fluid

• increase BP

Hypertension Response

• increase in renal secretion causing fluid loss

• depleted circulatory volume

• decrease CO, BP and ABP

First Line B/P Controls

• lifestyle changes

  • stress reduction

  • reduction of weight

  • exercise

  • decrease sodium intake

  • decrease alcohol intake

  • no smoking

Antihypertensive Meds and Prototypes

• Captopril (ACE Inhibitors)

• Losartan (ARBs)

• Amlodipine (CCB)

• Propranolol (BB)

• Furosemide/Nitro (Diuretics)

• Hydralazine (Direct Vasodilators)

ACE Inhibitors

• works in lung

• prevents ACE from conversion of angiotensin II (vasoconstrictor)

• decrease BP

• slight potassium increase

• loss of NA and fluid

• cause little change in CO and rate, decreases peripheral resistance

ACE Inhibitor Uses

• hypertension

• heart failure

• MI

ACE Inhibitor Adverse Effects

• angioedema (sudden swelling or welts under skin, common in areas of eyes, lips and swelling of tongue)

• neutropenia (serious complication of captopril)

• persistent irritating cough

• insomnia, hyperkalemia, teachycardia

• nausea, vomiting

ACE Inhibitor Contraindications

• potassium-sparing direutics such as spiralactone

• salt substitutes that contain potassium risk for hyperkalemia

• black box: pregnancy

Angiotensin II Receptor Blockers (ARB)

• ARBs are one of the recommended classes as first-line agents for controlling hypertension

• blocks vasoconstricing and aldosterone secreting effects of angiotensin II at receptors

• increases renal flow

• decrease systemic vascular resistance

• less likely to cause hyperkalemia, angioedema, cough

Angiotensin II Receptor Blockers (ARB) Uses

• first line agent to control HTN

• diabetic nephropathy

• patients who can not take ACE inhibitor

• less likely to produce dry cough

Angiotensin II Receptor Blockers (ARB) Uses

• dizziness

• muscle cramps

• heartburn

• diarrhea

• decreased sensation to touch

• angioedema

• hyperkalemia

• caution with herbs/food

• black box: pregnancy

Calcium Channel Blocker

• block calcium vessels

• lead to vasodilation of vascular smooth muscle

• decrease contraction force, oxygen consumption and HR

• slow AV node conduction

Calcium Channel Blocker Uses

• HTN

• CAD

• Angina

Calcium Channel Blocker Contraindications

• hypersensitivity

Calcium Channel Blocker Adverse Reactions

• edema of feet and hands

• pulmonary edema

• hypotension

• headache

• drowsiness

• fatigue

• dizziness

• flushing

• palpations

• nausea

• abdominal pain

Beta-Adrenergic Blockers (Beta Blockers)

• inhibits SNS activity

• beta 1 in heart

• decrease HR (neg chrono)

• decrease myo contractility (neg ino)

• decrease rate of conduction (neg dromo)

• alpha block adds vasodilation in meds like labetalol - (reduces renin release which decreases angiotensin II, causes vasodilation and promotes excretion of NA and water)

• dilates BP

• decreases vascular resistance

Beta-Adrenergic Blockers (Beta Blockers) Usage

• decrease HR

• decrease force of myocardial contraction

• decrease CO

• decrease renin

Beta-Adrenic Blockers (Beta Blockers) Contraindications

• extensive hepatic first pass

• first dose phenomenon

• black box warning: abrupt withdrawal for CAD

Vasodilators

• used in severe hypertension not responding to other medications

• acts directly on smooth muscle to cause vasodilation —> decrease BP

• most potent = nitroprusside

Vasodilator Use

• acts on arterioles to decrease B/P

• limited effect on HTN when used alone

Vasodilator Adverse Effects

• sodium retention

• H20 retention

Diuretics

• first line for mild HTN

• helps the kidneys get rid of excess water and salt

• reduces blood vol —> decrease BP

• categorized by where they function

• combination used when more than one variety is used together

• used with antihypertensive due to fluid retention

Heart Failure

• complex clinical syndrome resulting in insufficient oxygen supply to tissues and organs

  • decreased CO —> decreased tissue perfusion

  • EF is amount of blood pumped out of LV

• occurs when reduced EF of the LV

• occurs with defect in filling

• associated with CV disease

• sometimes reversible

• chronic, progressive

Heart Failure Risk Factors

• hypertension

• CAD

• certain comorbities

• genetic risk cardiomyopathy

Stages of Heart Failure

• stage A - high risk, no symptoms

• stage B - structural, no syptoms

• stage C - structural, previous or current symptoms

• stage D - refractory symptoms needing interventions

Classes of HF

• class 1 - no limit in activity, ordinary activity doesn’t cause undue symptoms

• class 2 - slightly limited, fatigue, SOB, palpitation during activity

• class 3 - marked limitation, fatigue, SOB, palpation at less than norm activity

• class 4 - struggle at rest, worsens with activit

Types of HF

• left sided systolic (HF with reduced EF)

• left sided diastolic (HF with same EF)

• right sided

• biventricular

Blood Flow in Heart

• superior vena cava / inferior vena cava

• right atrium

• tricuspid valve

• right ventricle

• pulmonary valve

• pulmonary artery

• pulmonary vein

• left atrium

• mitral valve

• left ventricle

• aortic valve

Left Sided HF

• most common form of HF

• results from inability of LV to:

  • fill during diastole

  • empty during systole

• blood backup into LA

• pulmonary hydrostatic pressure causes fluid leakage —> pulmonary edema

• observations:

  • pulmonary congestion/edema

  • S3/gallop

  • DOE

  • low O2

  • oliguria

Pulmonary Edema

• can cause severe hypoxemia

• monitor lung sounds for changes

• frothy blood tinged sputum, restless, cyanosis, confusion, tachypnea, tachycardia

• actions: O2, diuretics, vasodilators

HF with reduced EF

• systolic failure

• can’t pump effectively because:

  • low contraction

  • increased afterload

  • mechanical abnormalities

• decreased LV ejection fraction (LVEF)

Ejection Fraction Percentage

amount of blood pumped out of ventricle / total amount of blood in ventricle

HF with preserved EF

• diastolic HF

• inability of ventricles to relax and fill during diastole

  • decreased SV and CO

• primary cause is HTN

• same end result as systolic failure

Right Sided HF

• RV doesn’t pump effectively

• fluid backs up in venous system

• fluid moves into tissues and organs

• left-sided HF is most common cause

  • other causes: stenosis, regurgs, valve disease, etc.

Biventricular Failure

• both right and left

• inability of both ventricles to pump effectively

  • fluid build-up

  • venous engorgement

  • decreased perfusion to vital organs

  • compensatory mechanisms

BNP Levels

100 - Good!

101-299 - Mild Increase

300+ - Mild HF

600+ - Moderate HF

900+ - Severe HF

Natriuretic Peptides

• ANP, BNP

• released in response to increased BV and ventricular wall stretch

• high BNP = fluid retention

• causes diuresis, vasodilation and lowered BP

Complications of Heart Failure

• pleural effusion

• dysrythmias and dysyncronous contraction

• hepatomegaly

• cardiorenal syndrome

• anemia

Management of Heart Failure

• vary according to severity/cause of condition

• oral/IV meds

• lifestyle modifictaions

• supplemental O2

• surgical interventions

Heart Failure Patient Education

• nutrition

• low sodium diet

• fluid restriction

• daily weights

Heart Failure Meds and Prototypes

• Enalapril (ACE Inhibitors)

• Digoxin (Cardiac glycosides)

• Sacubitril/Valsartan (ARNi)

• Metoprolol (Beta Blocker)

• Furosemide (Diuretics)

• Milrinone (CIA)

ACE Inhibitors

• improve morbidity and mortality in HF with reduced EF

• block conversion of angiotensin I to II

  • promotes vasodilation (lowers BP, LV afterload and aldosterone)

• treats hypertension, acute + chronic HF & asymptomatic LV dysfunction

ACE Inhibitor Adverse Effects

• angioedema

• neutropenia

• increased cough

• hyperkalemia

ACE Inhibitor Contraindications

• taking NSAIDS

• pregnancy

• allergies

ACE Inhibitor Nursing Implications

• assess BP before and after

• check electrolytes

Cardiac Glycosides

• positive ino, neg chrono, neg dromo
  (increases contract, decreases rate, decreases conduction)

• increases CO, kidney function, SV

• decreases preload

• used to manage mild to moderate HF

• used to control ventricular response in adults with AFIB

Digoxin Adverse Effects

• life threatening:

  • AV block

  • cardiac dysrhythmias

  • PVCs

• nausea

• vomiting

• dizziness

• loss of appetite

• abdominal discomfort

• visual disturbances

• mental changes

Digoxin Antidote

digibind

ARN Inhibitors

• blocks vasoconstriction effects of RAAS

• stimulates vasodilation

• inhibits neprilysin and angiotensin II dependent release

• used to manage chronic HF with reduced EF

Adverse Effects of ARN Inhibitors

• hypotension

• hyperkalemia

• cough

• dizziness

• renal impairment

• angioedema

ARN Inhibitor Contraindications

• pregnancy

• allergy

• use with ARB/ACE

• hx of angioedema

ARN Inhibitor Nursing Implications & Education

• interaction with lithium, grapefruit, St. John Wart

• birth control, take as directed, move slowly, stay hydrated, signs and symptoms of angioedema