Pharmacy Block 2 HTN Flashcards
HTN is defined as sustained arterial BP of what measurements?
SBP >130
DBP >80
PT that is using anti-HTN medications
What is a strong predictor of CV disease in adults?
SBP in adults +50y/o
Sustained elevated BP is directly correlated to what six ailments?
MI Angina HF KF Early death 2* to CVD Retinopathy
What are the benefits of lowering BP?
Dec stroke rixk x 40%
Dec MI risk by 25%
Dec HF risk by 50%
Define Essential HTN
90% of HTNs that have no identifiable cause, can only be controlled
Major contributor- obesity
Define Secondary HTN
Comorbid Dz or drug induced
First step in treatment- removing offending agent/treatment of Dz
What are the most common secondary causes of Secondary HTN?
Renal dysfunction from chronic kidney disease
Renovascular disease
Define Resistant HTN
PT is not at the BP goal despite optimal dose of three Anti-HTNs from different classes including diuretic
Define Isolated Systolic HTN
SBP +140
DBP +90
What causes ISH?
Pathophysiological changes in arterial vasculature from the aging process
What is the Pulse Pressure equation?
What does a high number mean?
PP= SBP - DBP High= Increased arterial stiffness, increased CVD risk
What is the equation for BP?
BP= CO x TPR
Total Peripheral Resistance
Cardiac Output is the function of what 3 things?
Stroke Volume
HR
Venous Capacitance
What is the Cardiac output equation?
CO= HR x SV
Total peripheral resistance is a function of what two things?
Vascular constriction- periphery
Vascular hypertrophy- heart
CO largely determines ___
TPR largely determines __
SBP
DBP
How does Arterial BP fluctuate throughout the day?
Lowest during sleep
Sharp rise prior to awakening
Highest at mid-morning
Definition of CO
Volume of blood ejected per unit time
What is the Mean Arterial Pressure Equation?
MAP= CO x Systemic Vascular Resistance
Cardiac output can be affected what variables?
Blood Volume: Na, Mineralcorticoids, ANP
Cardiac factors: HR, contractility
What are the Neural Factors that affect TPR?
Constrictors (A-adrenergic)
Dilators (B-adrenergic)
What are the Local Factors that affect TPR?
Auto Regulation
Ionic (pH, hypoxia)
What are the Humoral Factors that affect TPR?
Constrictors- Angiotensin 2, Catecholamines, Thromboxanes, Leukotrienes, Endothelin
Dilators- Prostaglandins, Kinins, NO
The RAAS regulates what 3 things in the body?
Na
K
Fluid Balance
SNS is regulated largely by ______ via _____
Negative feedback
Baroreceptors
What is the most influential contributor to the homeostatic regulation of BP?
RAAS
What are the baroreceptors for the RAAS?
Juxtaglomerular Cells in afferent arterioles of kidney
Where is renin stored in the body?
Jux cells
What is the role of renin?
Converting angiotensinogen to Angiotensin 1
Renin release is stimulated by what 3 things?
Dec renal artery pressure/flow to kidney
Catecholamine activation of sympathetic nerves
Decreased Na and Cl in distal tubule
How does Angiotensin 2 increase BP?
Pressor and Volume Effects
Pressor- constriction, catecholamine release, inc SNS
Volume- Inc aldosterone synth from adrenal cortex
Angiotensin 2 has important actions at what 5 locations?
Vascular smooth muscle- constriction Adrenal cortex- aldosterone synth/release Kidney- inc Na absorption Heart- inc rate Brain- inc ADH release
Where does aldosterone main act?
It is controlled by what 2 things?
It regulates what 3 things?
Distal convoluted tubule
RAAS and K+
Na reabsorption, K secretion, Na/K+ATPase channel
3 drugs that effect the Sympathetic Nerve Terminals
Guanethidine
Guanadrel
Reserpine
4 drugs that affect the Vasomotor Center of the brain?
Methyldopa
Clonidine
Guanabenz
Guanfacine
What drug affects the sympathetic ganglia?
Trimethaphan
What drugs affect the B-receptors of the heart?
Propranolol
B blockers
What drugs affect the angiotensin receptors of large vessels?
Losartan
Angiotensin receptor blockers
What drugs affect the A-receptors of vessels?
Prazosin
A1 blockers
What drugs affect the kidney tubules?
Thiazides
What drugs affect the B-receptors of juxtaglomerular cells that release renin?
Propranolol
B blockers
What are 6 medications that affect vascular smooth muscles?
Hydralazine Minoxidil Nitroprusside Diazoxide Verapamil/CCBs Fenoldopam
Overall/basic function of diuretics
Lower BP by depleting body of Na and reducing volume
Overall/basic function of anti-adrenergic agents?
Inhibit cardiac function
Reduce peripheral resistance
Increase venous pooling
Overall/basic function of direct vasodilators?
Reduce BP by relaxing smooth muscles/dilating vessles
Overall/basic function of angiotensin blockers?
Reduce peripheral vascular resistance and blood volume
What drug has it’s action site in the PCT?
Acetazolamide
What drug has it’s action site in the descending loop of Henle?
What drug has it’s action site in the ascending loop of Henle?
Osmotic diuretics
Loop diuretics
What drug has it’s action site in the DCT?
Thiazides
What drug has it’s action site in the collecting duct?
K+ sparing
Thiazides can lower BPs by how much?
SBP- 15-20
DBP- 8-15
_____ have been shown to be the best tolerated of the medication classes used to treat HTN
Diuretics
Thiazides are not effective in PTs with what kidney issues?
CrCl < 30ml
SrCr > 2/5mg
Thiazides cause the body to lose what minerals?
Inc excretion of Na and Cl
Loss of K and Mg2
Dec urine Ca excretion
Reduced peripheral resistance
How long does it take for the HTN and diuretic actions of Thiazides to take effect?
HTN: 1-3wks
Diuretic: immediatley
As a class, Thiazides become ineffective when PTs GFR is below what level?
<30mls
Except- Metolazone, remains effective until 10-20mls
What is the only thiazide available by IV?
Chlorothiazide
What 3 things need to be monitord for in PTs taking Thiazides?
BUN
E+
BP
What happens if a PT taking a Thiazide takes Digoxin?
Induces Hypokalemia, causes ventricular arrhythmia
ACEIs reduction of Angiotensin 2 synthesis reduces what five things?
Smooth muscle constriction Aldosterone synthesis Na reabsorption HR ADH release
ACEIs lower BP by what methods?
Reducing peripheral resistance w/out inc CO, rate or contractility
Vasodilation
Reduces Na/water retention
Reduces SNS output