Hypertension drugs

What is hypertension?

SILENT KILLER

Per the CDC….

• 50% of US adults have HTN

• inreases risk of stroke and heart attack- major leading causes of death

• men > women

• highest rate among among African American & Hispanic population

What is HTN?

• aka high blood pressure

• consistent elevation of systemic force against arterial wall

• >130/90

What are common s/s of HTN?

• Headache

• Dizziness

• Blurred Vision

• Difficulty breathing

What are risk factors/causes of HTN?

• Smoking

• Poor diet

• Stress, emotions

• Stress, emotions

• Nursing education:

  • improve public awareness

  • increasing screening, teaching about early intervention which translate into prvention of disease

What are the treament plans with the different BP categories?

• Normal: none

• Elevated: Lifestyle changes

• High blood pressure (HTN stage 1): lifestyle changes and 1 medication (typically lisinopril)

• High blood pressure (HTN stage 2): lifestyle changes and 2 medications

• Hypertensive crisis: hospital, IV meds

BP=…..

Cardiac output (how much blood is pumped) x peripheral resistance (how narrow/stiff vessels are)

What are the key components of blood pressure?

• Systolic pressure: max pressure in arteries when the heart contracts

• Diastolic pressure: pressure in arteries when heart is at rest (refilling)

How do blood pressure meds work?

• Diuretics: decrease volume

• Beta blockers: decrease cardiac output

• ACE/ARB: decrease vasoconstriction and decrease volume

• CCB- decrease resistance

What are the main components of HTN?

• Blood volume

• Peripheral resistance

• Cardiac output

What affects blood volume?

• Fluid loss: dehydration

• Fluid retention: aldosterone, ADH

What affest peripheral resistance/diameter of arteries?

• Sympathetic nervoud system activity

• Renin/angiotensin ll

• Increase in blood viscosity

What affects cardiac output?

• Stroke volume: preload, contractility, afterload

• Heart rate: sympathetic nervous system activity, parasympathetic nervous system activity, Epinephrine

What is blood volume?

• total amount of blood in vascular system (around 5 liters)

• volume can change due to disease, drugs, regulatory factors

• more blood volume = increased pressure

• controlled primarily by the kidneys

What is peripheral resistance/diameter of arterioles?

• blood travelling around the vasculature at a high rate of speed comes in contact with the smooth endothelium of the vessels, where friction slows it down

• the friction is called peripheral resistance

  • vessels constrict: bp increases

  • heart pumps faster: bp usually increases

  • drugs that raise peripheral resistance: raise bp and vice versa

  • SNS: causes vasoconstriction which increases peripheral resistance and bp

  • PNS: little direct effect on most blood vessels, mainly affects heart rate

What is cardiac output?

• the volume of blood pumped in a ventricle per minute

  • heart rate (# of beats/minute)

  • stroke volume (amount of blood (mL) pumped by the blood in one contraction

  • Heart Rate x Stroke Volume = Cardiac Output

How do we regulate blood pressure?

• Cardiovascular- vasomotor center signals from baroreceptros and chemoreceptors; sympathetic nerves

• CNS: medulla oblongata sends signals

• Kidneys- RAAS system

What hormones regulate blood pressure?

• epinephrine/nor-epi

• angiotensin ll

• aldosterone

• ADH

What are types of HTN?

• Primary (essential)- no single identifiable cause (about 90% of HTN)

• Secondary- a specific cause can be identified, for example….

  • Cardiovascular disease, chronic kidney disease, heart failure, drugs

What are the classes of medication to treat HTN?

• “ABCD”

• ACE inhibitors (Angiotensin-Converting Enzyme), ARB’s (Angiotensin Receptor Blocker)

• Beta Blockers

• Calcium Channel Blockers

• Diuretics

  • loop diuretics

  • thiazide diuretics

  • potassium (K+) sparing diuretics

How do diuretics work for HTN?

• Reduce blood volume

• Water and sodium excretion in the urine

• Diuretics act by inhibiting sodium reabsorption at specific sites along the kidney's nephron, increasing urinary water loss

What are the main types of diuretics?

• Potassium-Wasting

  • hydrochlorothiazide

• Potassium-Sparing

  • spironolactone

What is hypokalemia?

• lethargy and fatigue

• leg cramps

• low, shallow respirations

• lethal cardiac dysrhythmias- tachycardia

• low pulse (thready pulse)

• decreased GI motility

• flat T waves looks like a U wave

What is hyperkalemia?

• M- muscle weakness

• U- urine: oliguria, anuria

• R- respiratory distress

• D- decreased cardiac contractility- bradycardia

• E- ECG changes- peaked T waves

• R- reflexes: hyperreflexia or areflexia (flaccid)

What are the non-diuretic medications for HTN?

• ACE inhibitors (Angiotensin-Converting Enzyme)- ends in “pril”

• ARB’s (Angiotensin Receptor Blocker)- ends in “tartan”

• Beta Blockers (BB)- ends in “lol”

• Calcium Channel Blockers (CCB)- ends in “divine, zem, amil”

What is the worst possible side effect of ACE inhibitors?

• Angioedema (caused by pro-inflammatory bradykinins)

  • swelling of lips, eyes, throat, and other body regions —> lead to throat closure

  • most often begins within hours/days of starting medication

How do Beta 1 selective- blockers work?

• Work by blocking adrenergic receptors (blocks the fight or flight response)

• Decrease HR and heart contractility —> decreased cardiac output and lower systemic blood pressure

• also work by blocking B1 in the juxtaglomerular apparatus which inhibits the secretion of renin and the formation of angiotensin ll

What’s the connection between potassium and insulin?

• potassium plays a key role in helping the pancreatic beta cells (that make insulin) do their job

• these cells rely on ptassium to generate electrical signals that trigger the release of insulin after you eat

• when potassium is low

  • the electrical activity of beta cells gets disrupted

  • as a reult, less insulin is releases, even when blood sugar is high

  • this can lead to impaired glucose tolerance and make blood sugar harder to control

What is hypertensive crisis?

• BP > 180/120

• can cause organ damage

• most common cause is uncontrolled, poorly manages essential HTN

• treatment: IV BP meds (don’t want to drop BP too fast- hypotension)

What is the contraction of muscles regulated by?

• the amount of calcium ions inside the cell