Anti-Hypertensive Flashcards
Cardiovascular mortality risk doubles with each what BP increment?
20/10mmHG
What is hypertension?
> 130/>80
CO=
SV X HR
SV=
EDV-ESV
BP=
CO X SVR
Rationale for reducing CO?
Reduce blood volume
Reduce HR
Reduce SV
Rationale for reducing SVR?
Dilate systemic vasculature
5 anatomical site of BP control:
- Resistance arterioles
- Capacitance venules
- Pump output heart
- Volume kidneys
- CNS- sympathetic nerves
4 Renin angiotensin aldosterone system (RAAS) antagonists
- Angiotensin-converting enzyme (ACE) inhibitors
- Angiotensin II receptor blocker (ARBs)
- Neprilysin inhibitor plus ARBs
- Aldosterone antagonists (Potassium sparing diuretics)
Pathway for renin angiotensin aldosterone system (RAAS)
Angiotensinogen (liver) Angiotensin I from renin (kidney) Angiotensin II from ACE (lungs) Arteriole vasoconstriction and adrenal cortex Aldosterone Sodium retention
What does ACE inhibit
Angiotensin I and bradykinin
5 common clinical uses for ACE inhibitors
- Heart failure
- CAD
- HTN
- Chronic renal disease with proteinuria
5 adverse effects from ACE inhibitors
- Increase serum potassium
- Acute renal failure
- Pregnancy
- Dry cough and angioedema (rare)
- Hypotension in patients with volume and/or salt depletion
What does ACE inhibitors drug name end with?
“pril”
What does ARBs inhibit?
Angiotensin II attaching to the receptors to allow for vasoconstriction and aldosterone secretion
4 common clinical uses for ARBs
- Heart failure
- CAD
- HTN
- Chronic kidney disease with proteinuria
When is ARBs most common used?
As an alternative to ACE inhibitors when patients develop dry cough
4 adverse effects for ARBs
- Increase serum potassium
- Acute renal failure
- Pregnancy
- Hypotension in patients with volume and/or salt depletion
What does ARBs dug name end in?
“sartan”
What does neprilysin inhibitor plus ARBs inhibit?
Block break down of peptides (valsartan and LBQ675)
Block angiotensin II connecting to it’s receptors
Common clinical uses for neprilysin inhibitor plus ARB
Heart failure
5 Adverse effects of neprilysin inhibitor plus ARB
Hyperkalemia Cough Angioedema Renal function deterioration Hypotension
3 Contraindications for neprilysin inhibitor plus ARB
36 hours of ACE inhibitors (angioedema)
Pregnancy
Bilateral renal artery stenosis
What does direct renin inhibitor (DRI) inhibit?
Renin
Clinical uses for DRI
HTN
What is DRI available to be in combo with?
Amlodipine + HCTZ
What is the is the drug name for DRI?
Aliskiren (tekturna)
5 Adverse effects for DRI
Hyperkalemia Angioedema Renal function deterioration Diarrhea Hypotension in patients with volume and/or salt depletion
2 Contraindications for DRI
Aliskiren with ARBs or ACEIs in patients with DM
Pregnancy
Risk of hyperkalemia and renal impairment elevates when DRI is used with what in DM patients?
ARBs and ACEIs
Aldosterone antagonists inhibit what?
Sodium and water retention
What 2 drugs are aldosterone antagonists
Spironolactone
Eplerenone
How does aldosterone antagonists increase BP?
Induce sodium and water retention
4 clinical uses for aldosterone antagonists
Hyperaldosteronism
Resistant HTN
Heart failure
MI with LV dysfunction
3 Adverse effects for aldosterone antagonists
Renal dysfunction
Hyperkalemia
Endocrine abnormalities
What can aldosterone antagonists cause?
Myocardial, renal, and vascular fibrosis
Contraindication for aldosterone antagonists
- SCr >2.5 (men) >2 (women)
2. Potassium >5
2 mechanism of actions for diuretics (decrease BP)
- Depleting body of sodium and H2O
2. Reducing blood volume (decrease SV)
6 types of diuretics
- Loop diuretics
- Thiazide diuretics
- Potassium sparing diuretics
- Osmotic diuretics
- Carbonic anhydrase inhibitors
- Vasopressin (ADH) antagonists
3 uses for loop diuretics
- Edematous
- Hyperkalemia
- HTN (2nd line)
7 Adverse effects for loop diuretics
- Na/volume depletion
- Hypokalemia
- Hypocalcemia
- Hypomagnesemia
- Metabolic alkalosis
- Hyperuricemia
- Ototoxicity
4 thiazides
Hydrochlorothiazide
Chlorthalidone
Indapamide
Metolazone
Is thiazide 1st or 2nd line to treat HTN?
First line
Is thiazide more or less potent than loops?
Less potent
8 adverse effects of thiazide
- Hypovolemia
- Hypokalemia
- Hypoatremia
- Hypochloremia
- Hypomagnesemia
- Hyperkalemia
- Hyperuricemia
- Metabolic alkalosis
2 different potassium sparing diuretics
Sodium channel blockers
Aldosterone receptor antagonists
Are potassium sparing diuretics weak or strong diuretics
Weak
What is the adverse effect for potassium sparing diuretics?
Hyperkalemia
What do central anti-adrenergics target?
Adrenergic neurons in CNS
What does central anti-adrenergics prevent?
Releasing of catecholamines
How is central anti-adrenergics controlled?
Negative feedback inhibition (alpha 2= inhibit NE release)
Where on the brain is the inhibitory effect on NE located at?
Prefrontal cortex
What drug is a central anti-adrenergic (alpha2 agonists)
Clonidine
What 4 things specifically lower BP in central anti-adrenergics?
- Lower venous return
- Lower TPR
- Lower HR
- Lower SV
What does methyldopa get converted into?
Methylnorepinephrine
What does methylnorepinephrine do when released?
NOT activate adrenergic receptors
CAN act on the alpha2 receptors (further inhibit NE release)
What is a big adverse effect of central anti-adrenergic?
Rebound HTN with withdrawal
4 clinical uses of central anti-adrenergic
- HTN (NOT 1st line and resistant HTN)
- ADHD
- HTN in pregnancy
- Treatment of withdrawal
2 non-selective alpha antagonists
Phenoxybenzamine
Phentolamine
What is phenoxybenzamine?
Irreversible, non-competitive antagonist
What is phentolamine?
Reversible, competitive antagonist
How are phenoxybenzamine and phentolamine treated?
Pheochromocytoma
When is phentolamine used?
HTN crisis
4 adverse effects of nonselective alpha antagonists
- Reflex tachycardia
- Postural hypotension
- Cardiac arrhythmias
- Ischemic cardiac events
Adverse effect of phentolamine?
Stimulates GI SM and enhance gastric acid secretion
Adverse effects of phenoxybenzamine?
Mutagenic
What does alpha1 antagonists do?
Inhibit binding of NE to Postsynaptic alpha1 receptors
What does alpha1 antagonists cause?
Relax SM
Decrease PVR and venous return
Clinical use of selective alpha1 antagonists
HTN (not 1st line)
5 adverse effects of selective alpha1 antagonists
- Postural hypotension
- Syncope
- Fluid retention
- Nasal congestion
- Drowsiness
What is 1st does phenomenon
Faintness and/or syncope within 30min-6hrs after initial dose
Use low initial dose at bedtime
Titrate slowly
What 3 locations at beta1 receptors?
Heart
SA and AV node
Kidneys
What 3 locations are beta2 receptor
Lungs
Vascular SM
Liver/pancreas
Beta1 blockade cause?
Decrease HR
Decrease contractility
Decrease renin release
Beta2 blockade cause?
Bronchoconstriction
Decrease insulin secretion
Vasoconstriction
Theorized effect on beta-blockers
Inhibit release of NT and decrease sympathetic activity
Beta1 selectivity for heart
Bradycardia
Negative inotropy
Decrease BP
Beta1 selective on lungs
Less bronchospasm
Beta1 selectivity with peripheral effects
Metabolic effects
Circulatory
2 effects on non-selective beta1 and beta2
- Similar cardiac and antiHTN effects
2. More pulmonary and peripheral effects
What does beta blocker drugs name end in?
“olol”
5 beta blocking effects
- Negative chronotropic
- Negative dromotropic
- Anti-arrhythmic
- Negative inotropic
- Anti-ischemic
3 non-vasodilation BB hemodynamics:
- Acute decrease in CO ~20% with compensatory reflex rise in SVR
- SVR returns to baseline
- BP lowers chronically from decreased HR and CO
Are BB first line antiHTN?
NO
Why aren’t BB 1st line antiHTN? (3)
- Other drugs have better CV protection
- Lowers brachial BP but not central BP
- Mortality may be higher with atenolol
What does vasodilation BB BP reduction come from?
Decreased HR and SVR
4 BB contraindications
- Bradycardia
- Severe asthma or bronchospasm
- Severe depression
- Cardiogenic shock or hypotension
6 BB adverse effects
- Smooth muscle spasm
- Exaggeration of the cardiac therapeutic actions
- CNS penetration
- Worsened quality of life
- Adverse metabolic side effects
- Withdrawal phenomenon
3 main clinical uses for BB
- Ischemic heart disease (chronic stable angina and acute coronary syndrome)
- Heart failure with reduced EF (metoprolol succinct, carvedilol, bisoprolol)
- Tachyarrhythmias
2 different types of Ca++ channels:
- T(transient) type
2. L type
What is t-type Ca channel?
- opens at more negative potentials
- dominant in SA node
What is L-type Ca channel?
- located on vascular SM, cardiac myocytes, cardiac nodal tissue
- dominant in AV node
- required for initiation of contraction via Ca++
2 types of Ca channel blockers?
- Non-dihydropyridines (NON-DHPs)
2. Dihydropyridines (DHPs)
What do NON-DHPs effect?
SA
AV
Contractility
What do DHP effect?
Contractility
Vasodilation
NON-DHPs effect on:
SA, AV, inotropic, myocardial blood flow, peripheral arterioles
Normal/decrease Decrease Decrease Increase Increase
DHPs effect on:
SA, AV, inotropic, myocardial blood flow, peripheral arterioles
Normal Normal Normal Increase Increase
BB effects on:
SA, AV, inotropic, myocardial blood flow, peripheral arterioles
Decrease all
2 NON-DHPs medications
Verapamil
Diltiazem
Verapamil
More cardio selective
More potent HR lowering effect
Stronger suppression of contractility
Diltiazem
More effective vasodilator
Better antiHTN
Moderate suppression of contractility
Clinical uses for NON-DHPs (4)
HTN
Supreventricular tachyarrhythmias
Chronic stable angina
Coronary spasm
3 contraindications of NON-DHPs
Severe hypotension or cardiogenic shock
LV dysfunction (<40%)
Bradycardia
Is nifedipine DHPs long or short acting?
Short
How does DHPs work?
Rapid vasodilation
Rapid drop BP
Rapid reflex adrenergic activation with tachycardia
Increase demand
Unusual side effects of DHPs (4)
Muscle cramps
Myalgia
Hypokalemia
Gingival swelling
How long or short acting DHPs preferred?
Long
Is DHPs first or second line HTN?
First
4 clinical uses for DHPs
HTN
Chronic stable angina
Coronary spasm
Raynaud’s phenomenon
Chief side effect of DHPs?
Ankle edema
2 HTN emergency meds
Nicardipine IV
Clevidipine IV
Tunica intima
Endothelial cells
Tunica medica
SM cells
Sheets of elastin
Tunica externa
Loosely woven fibers of collagen
How do nitroglycerin (glyceryl trinitratel, NTG) work?
NTG produce NO
NO goes to SM cells
Stimulate guanylyl cyclase
Increase cGMP (vasodilates veins and arteries)
What do organic nitrates do to preload and afterload?
Decrease because of the vasodilation
What does organic nitrates do to myocardial oxygen consumption and oxygen delivery to heart tissue?
Decrease myocardial oxygen consumption
Increase oxygen delivery to heart tissue
3 most common ways to receive NTG?
Sublingual/spray
IV
Transdermal patch
2 nitrate preparations:
Isosorbid dinitrate (ISDN) Isosorbid mononitrate (ISMN)
What is isosorbid dinitrate?
Low bioavailability, high first pass metabolism
Converted to active mononitrate metabolite (via liver)
What is isosorbide mononitrate?
High bioavailability, no first pass metabolism
How does nitrate preparations produce vasodilation?
ISDN -> ISMN -> NO -> cGMP -> vasodilation
5 clinical uses of organic nitrates
- Chronic stable angina
- Unstable angina and ACS
- Acute HR and pulmonary edema
- Chronic heart failure
- HTN
Contraindication of nitrate?
Right ventricular infarction
4 Adverse effects of nitrate?
Headache
Hypotension, dizzy, syncope
Reflex tachycardia
Halitosis (bad breath)
Serious nitrate interaction
Decrease BP
Syncope
Erection
Nitrate tolerance (tachyphylaxis) (3)
- loss of nitrate-induced vasodilation
- reduced nitrate-induced BP lowering effect
- attenuation of nitrate-induced anti-ischemic effect
What is Monday disease at explosive factory?
Nitrate tolerance
How long does nitrate tolerance occur?
2-3days
What are 2 parenteral vasodilators?
Sodium nitroprusside
Fenoldopam
What 3 things are nitroprusside?
Complex of iron
Cyanide groups
Nitro so moiety
Does sodium nitroprusside cause tolerance?
No
How does sodium nitroprusside cause vasodilation?
Rapid uptake by RBCs
NO and cyanide
NO activates GC -> cGMP and causes vasodilation
What does sodium nitroprusside cause in preload and afterload?
Decreases in both
What does normal LV function do with sodium nitroprusside?
Decrease BP
What does severely impaired LV function do with sodium nitroprusside?
Decrease afterload leads to rise in SV and CO
What is sodium nitroprusside toxicity?
Cyanide toxicity
What is treatment for cyanide toxicity with sodium nitroprusside?
Hydroxocobalamin, sodium thiosulfate
3 additional toxicity problems with sodium nitroprusside?
Hypotension
Coronary steal
Increase ICP
3 Sodium nitroprusside clinical uses?
HTN emergencies
Acute decompensated HF
Perioperative HTN in cardiac surgery
In HF, a reduced afterload can do what to SV and CO?
Enhance them
2 therapeutic uses for hydralazine (oral direct vasodilator)?
HTN
HF with reduced EF
Therapeutic uses of minoxidil (oral direct vasodilator)?
Severe HTN poorly responsive to other HTN drugs
LAST RESORT
3 adverse effects of oral direct vasodilators
Headaches, flushing
Baroreceptor (mediated reflex tachycardia)
Salt and water retention (edema)
What is fenoldopam?
Selective agonist of D1-like dopamine receptor
Is fenoldopam rapid or slow acting?
Rapid acting arteriolar vasodilator
When is fenoldopam used?
HTN emergencies and postop HTN
What are the 2 major toxicities with fenoldopam?
Reflex tachycardia
Hypokalemia
What should be done when BB are used with fenoldopam?
With caution: substantial hypotension because BB inhibit sympathetic reflex