Antihypertensives Flashcards
ACE inhibitors mechanism
No reflex tachycardia, etc.
Decreased sodium and H2O retention
Increased renin
Increased bradykinin (potent vasodilator)
ACE inhibitor drugs
Captopril
Enalapril
Lisinopril
ACE inhibitors Description
Decrease PVR therefore decrease BP
- *Decrease diabetic nephropathy**
- *Decrease albuminuria**
ACE inhibitors indications
HTN-must effective in young white patients (black and elderly have low renin … add a diuretic)
CHF
DOC patients s/p MI
ACE inhibitors Adverse
Hyperkalemia
Dry cough
Rash, fever, altered taste, hypotension
Angioedema (supervise first dose)*
Acute renal failure in patients with BILATERAL RENAL ARTERIAL STENOSIS
Decreased vasoconstriction on efferent therefore decreased GFR, elevated creatinine
ACE inhibitor contraindications
Pregnancy–fetal hypotension leading to renal agenesis and anuria
Hyperkalemia
Bilateral renal a. stenosis
Angiotensin receptor blockers (ARB) Drugs
Losartan
Valsartan
Angiotensin receptor blockers description
Alternative to ACE - I
Blocks the ATII receptor
Angiotensin receptor blockers mechanism
Very similar to ACE-I
Decreased PVR decreased BP
Decreased nephrotoxicity
No effect on bradykinin
Angiotensin receptor blockers Indication
HTN (white people)
CHF
s/p MI
Angiotensin receptor blockers adverse effects
Similar to ACE-I
Angio edema risk is much lower (related to bradykinin)
Angiotensin receptor blocker contraindications
Pregnancy - fetal hypotension, renal failure, anuria
Hyperkalemia
Bilateral renal a. stenosis
Renin inhibitor drugs
Aliskiren
Renin inhibitor mechanism
Inhibits production of both ATII and aldosterone
Aliskiren contraindications
Pregnancy
Bilateral renal a. stenosis
Hyperkalemia
Calcium channel blocker drugs
Verapamil
Diltiazem
Nifedipine
Amlodipine
Verapamil Description
Calcium channel blocker
Non dihydropyridine
Least selective
Cardiac and vascular smooth muscle effects
Verapamil mechanism
Bind to L type calcium channels in the heart and muscle of the peripheral vasculature ->decreased calcium entry -> relaxation of muscle -> -ve inotropism and/or vasodilation
Verapamil indication
Used in patients with angina, migraine or SVT
Used when first line agents are ineffective or contraindicated (patients with diabetes, asthma and PVD)
Effective in blacks and whites
Intrinsic natriuretic effect -> no need to add a diuretic
Verapamil adverse
High dose of short acting -> increased risk for MI
- *Reflex tachycardia**
- Constipation*
Verapamil contraindication
**CHF due to -ve inotropic effects **
Diltiazem description
Calcium channel blocker
Non dihydropyridine
A little more selective for vasculature than verapamil but still affects heart
Good side effect profile
Diltiazem mechanism
Bind to L type calcium channels in the heart and muscle of the peripheral vasculature -> decreased calcium entry -> relaxation of muscle -> -ve inotropic effects and/or vasodilation
Diltiazem indication
Pts with angina, migraine or SVT
Used when first line agents are ineffective or contraindicated (diabetes, asthma and PVD)
Effective in blacks and whites
Intrinsic natriuretic effect -> no need to add a diuretic
Diltiazem Adverse
High dose short acting increases risk of MI
Reflex tachycardia
Nifedipine and Amlodipine description
Dihydropyridines
Act only on smooth vascular muscle
Second gen amlodipine has little interaction with digoxin and warfarin
Nifedipine and amlodipine mechanism
Calcium channel blockers
Greater affinity for vasculature so they don’t cause a decrease in CO
Very useful for HTN but not arrhythmias
Nifedipine and amlodipine indication
Used when first line agents are ineffective or contraindicated (diabetes, asthma, PVD)
Effective in blacks and whites
Intrinsic natriuretic effect -> no need to add a diuretic
Nifedipine and Amlodipine Adverse
Hypotension -> dizziness, HA, fatigue, peripheral edema
Bradycardia
Heart block
Thiazides drugs
Chlorthalidone
Hydrochlorothiazide
Metolazone
Thiazide indications
DOC for black and elderly (with normal renal and cardiac function)
Thiazide Mechanism
Increased sodium and H2O excretion therefore decreased ECF -> decreased CO and renal blood flow (in the long term, there is normal plasma volume but decreased PVR)
Thiazide adverse
**Hypokalemia** Hyperuricemia Hyperglycemia Hypomagnesium Hyperlipidemia
Thiazide contraindications
Diabetes
Loop Diuretics
Ethacrynic acid
Furosemide
Torsemide
Loop diuretics description
Prompt action in pts with poor renal function or heart failure
Loop diuretic mechanism
decreased renal vascular resistance
increased renal blood flow
Loop diuretics indication
DOC for pts with poor renal function or unresponsive to other diuretics ex. thiazide
Amiloride and Triamterene
ENaC
Decrease the potassium lost in urine caused by thiazide or loop diuretics
Disopyramide description
Antiarrhythmic
Class 1A Stronger -ve inotrope than quinidine and procainamide Strong antimuscarinic properties Causes peripheral vasoconstriction Blocks K channels
Disopyramide indication
Antiarrhythmic
Supraventricular and ventricular arrhythmia
Disopyramide adverse
Antiarrhythmic
Pronounced -ve inotropic effects
Cardiac failure without preexisting myocardial dysfunction
Severe antitmuscarinic effects (dry mouth, urine retention, blurred vision, constipation, etc)
Class 1 A general
Antiarrhythmic
Sodium channel blockers
Never drug of choice
Ventricular and Supraventricular
Class 1A effect
Antiarrhythmic
Slow phase 0 depolarization (sodium channels)
Also prolongs phase 3 (potassium channels)
Slowing of conduction, prolonging AP & increase ventricular effective refractory period
Intermediate speed of association with activated and inactivated Na channels -> affects normal healthy tissue too
Procainamide, Disopyramide, and Quinidine
Class 1 B general
Antiarrhythmic
Sodium channel blocker
Ventricular only
Class 1 B effect
Antiarrhythmic
Slows phase 0 and decreases slope of phase 4
Minimally shortens phase 3 repolarization (no clinical effect)
Little effect of depolarization in normal cells
Rapid association/dissociation with sodium channels
Used primarily in ventricular arrhythmia (atria is too fast)
Tocainide adverse
Antiarrhythmic
Severe hematological and pulmonary toxicity
Mexiletine adverse
Antiarrhythmic
Mainly CNS and GI
Lidocaine is drug of choice when?
Antiarrhythmic
DOC for V tach and V fib after cardioversion in acute ischemia
Lidocaine toxic dose produces
Antiarrhythmic
Convulsions and coma
Class 1 C general
Antiarrhythmic
Sodium channel blocker
Ventricular and supraventricular
Class 1C effect
Antiarrhythmic
Markedly depress phase 0 of AP, no change in repolarization (K)
Slowing of conduction of AP, but little effect on duration or ventricular effective refractory period
Associate and re-associates slowly with sodium channels -> prominent effects even in normal cells ***Most likely of class 1s to cause arrhythmia***
Propafenone description
Antiarrhythmic
Class 1C
Decreases slope of phase 0 without affecting duration of AP
Prolongs conduction and refractoriness in all areas of the myocardium
Reduces spontaneous automaticity
Propafenone indication
Antiarrhythmic
Life threatening ventricular arrhythmia and maintenance of normal sinus rhythm in patients with symptomatic a fib
Class II mechanism
Antiarrhythmic
Beta blockers
Supraventricular only
Class II effect
Antiarrhythmic
Reduce HR and myocardial contractility (beta 1)
Prolongs repolarization at AV node and decreased slope of phase 4 (blocking adrenergic release) -> slows conduction of impulses through the myocardial conduction
Reduce rate of spontaneous depolarization in cells with pacemaker activity
Little effect on AP in most myocardial cells
Class III mechanism
Antiarrhythmic
K channel blockers
Ventricular and supraventricular
Class III effect
Antiarrhythmic
Blocks repolarizing K channels Prolongs AP (and QT interval) without altering phase 0 or resting membrane potential Prolongs effective refractory period
ALL have potential to induce arrhythmia
Amiodarone adverse main
Antiarrhythmic
Interstitial pulmonary fibrosis
Blue / gray skin discoloration due to iodine accumulation
Amiodarone contraindications
Antiarrhythmic
Patients taking digoxin, theophylline, warfarin, quinidine or have bradycardia, SA or AV block, severe hypotension, or respiratory failure
Dofetilide
Antiarrhythmic
Potent and pure K channel blocker
Class III
Dofetilide indication
Antiarrhythmic
Maintaining or conversion to norma sinus rhythm in chronic a fib / flutter
Dofetilide Adverse
Antiarrhythmic
HA, chest pain, dizziness, v tach, Torsades (prolongs QT interval)
Class IV mechanism
Antiarrhythmic
Calcium channel blockers
Supraventricular only
Class IV effect
Antiarrhythmic
Blocks L type calcium channels
Decrease inward calcium current -> decrease rate of phase 4 spontaneous depolarization
Slows conduction in SA and AV nodes
Major effects on vascular smooth muscles and heart
Use primarily for supraventricular arrhythmia
Digoxin description
Antiarrhythmic
Shorten refractory period in atrial and ventricular myocardial cells
Prolongs effective refractory period and diminishes conduction velocity in AV node
Digoxin Indication
Antiarrhythmic
Control ventricular response rate in A fib and flutter with impaired left ventricular function or heart failure
Mechanism of action
Heart failure- +ve inotrope -> increases intracellular calcium
Arrhythmia - Direct AV node blocking effects (inhibits calcium currents) and vagomimetic properties (activates ACh mediated K currents in the atrium)
Major indirect actions
Hyperpolarization, shorten atrial APs, increase AV node refractoriness -> decrease fraction of impulses that are conducted through the node
Digoxin adverse
Antiarrhythmic
Toxic dose -> ectopic ventricular beats (v tach and V fib)
Adenosine description
Antiarrhythmic
Naturally occurring nucleoside (P1r agonist)
High dose: Decrease conduction velocity and prolongs refractory period as well as decreases automaticity in AV node
Adenosine indication
Antiarrhythmic
DOC for abolishing acute SVT (emergency situations)
Lidocaine is used in acute V tach emergencies
Mechanism of action
Enhanced K conductance; decrease cAMP mediated Calcium influx -> hyperpolarization, especially in the AV node
Adenosine PK
Antiarrhythmic
half life 15 sec
Adenosine adverse
Antiarrhythmic
Low toxicity - Flushing, burning, chest pain (similar to MI, hypotension)
Bronchoconstriction in asthmatics (may last up to 30 mins)
Magnesium description
Antiarrhythmic
Functional calcium antagonist
Magnesium indication
Antiarrhythmic
Torsades de pointes (prolonged QT interval)
Digitalis induced arrhythmia (lidocaine also used)
Prophylaxis of arrhythmia in acute MI
Atropine indication
Antiarrhythmic
Used in bradyarrhythmia to decrease vagal tone -> increased HR
Rhythm control
Antiarrhythmic
Restore and maintain sinus rhythm -> generally involves drugs acting on the AV node to slow conduction Class IC (flecainide and propfenone) and Class III (amiodarone and dofetilide)
Rate Control
Antiarrhythmic
Control ventricular rate while allowing atrial fibrillation to continue
-ve dromotropic agents to slow conduction in the AV node
Calcium channel blockers, Beta blockers, digoxin
In the treatment of hypertension, a reduction in cardiac output is most likely to result in the development of which of the following? Chronic cough Periorbital edema Peripheral edema Peripheral neuropathy Type 2 Diabetes
Peripheral edema
A reduction in body fluid volume is most likely to result in the development of what?
Reflex tachycardia
One of the potential consequences of reducing blood pressure is increasing renin activity. Which of the following agents affects the renin-angiotensin process in the body? Atenolol Captopril Minoxidil Nifedipine Verapamil
Captopril
Spironolactone
Eplerenone
Aldosterone antagonist -> inhibition of Na+ and H2O retention -> inhibition of vasoconstriction
Decreased cardiac remodeling
1st line in patients with HTN and severe LV dysfunction
-reduced K+ excretion-> risk of hyperkalemia
Atenolol & Metoprolol mechanism
Beta 1 selective
Decreased CO, contractility and HR
Decreased CNS sympathetic output (especially with exercise)
Decreased NE and renin (Beta1) -> decreased ATII and aldosterone
Atenolol & Metoprolol, Propanolol, Pindolol indication
More effective in young/white patient
DOC only for patients with CAD or left ventricular dysfunction and HTN
Atenolol & Metoprolol, Propranolol, Pindolol PK
May take weeks to develop full effects
Atenolol, Metoprolol, Propranolol, Pindolol Adverse
Bradycardia, CNS effects, hypotension, impotence, lipid disturbance (decreased HDL, increased TAG), hypoglycemia
Abrupt withdrawal -> angina and MI in patients with heart disease
Propranolol contraindication
Asthma and COPD, sinus bradycardia
Pindolol, Propranolol, Atenolol, Metoprolol Contraindication
Sinus bradycardia, mask symptoms of hypoglycemia (diabetics)
Pindolol indication
B partial agonist
Preferred beta blocker in pregnancy
Doxazosin, Prazosin, Terazosin Class
alpha blockers
Alpha blocker drugs for HTN
Doxazosin, Prazosin, Terazosin
Doxazosin, Prazosin, Terazosin Mechanism
Alpha blockers
Decreased PVR and MAP by relaxation of arterial and venous smooth muscle
Minimal change in CO, renal blood flow and GFR -> no long term tachycardia
Doxazosin, Prazosin, Terazosin Description
Competitive inhibition of alpha one receptors
Sodium and Water retention-> usually give with a diuretic
Doxazosin, Prazosin, Terazosin Indication
Alpha blocker
Mild to moderate HTN in combination with propranolol or a diuretic (less common now due to adverse effects)
BPH
Doxazosin, Prazosin, Terazosin Adverse
**Reflex tachycardia and orthostatic hypotension may be seen with first dose, but not long term (alpha 2 blocks response by inhibiting NE) -> ameliorate with beta blocker
Dizziness, drowsiness, HA, fatigue, nausea, palpitations
Doxazosin contraindications
Has been shown to increase rate of CHF
Labetalol class
mixed alpha beta blocker
Labetalol description
NO reflex tachycardia or increased CO (beta 1 effect is greater)
Safe in PREGNANCY
Labetalol indication
long term treatment of HTN
HTN emergencies: IV admin-> rapid drop in BP
Labetalol Adverse effects
Orthostatic hypotension
Labetalol contraindication
Pheochromocytoma
Clonidine & methyldopa class
central acting alpha 2 agonist
Central acting alpha 2 agonist description
Clonidine & Methyldopa
Does not decrease renal blood flow or GFR
Clonidine mechanism
Decreases sympathetic outflow (NE) by acting on presynaptic auto receptors -> decreases PVR and CO -> decreases BP
Clonidine PK
Oral; well absorbed. Administer with diuretic (sodium and water retention)
Clonidine adverse
Sedation, dry mouth, dizziness, HA, sexual dysfunction are common
Rebound HTN after abrupt withdrawal
Methyldopa mechanism
Decreased sympathetic outflow -> decreased PVR and BP
CO not affected
Methyldopa indication
DOC Pregnancy induced HTN
Renal insufficiency
Methyldopa PK
Oral; well absorbed
Administer with diuretic
Methyldopa adverse
Sedation, dry mouth, dizziness, HA, sexual dysfunction are common
Rebound HTN after abrupt withdrawal
Methyldopa contraindication
Can cause positive Coombs test, hemolytic anemia, hepatitis
Hydralazine class
Direct vasodilator
Hydralazine description
Never 1st line treatment
Direct acting smooth muscle relaxant
Reflex tachycardia, increased plasma renin ->Sodium and water retention
(coadmin with a diuretic and betablocker)
Hydralazine Mechanism
Opening of Potassium channels in smooth muscle -> arteriolar dilation (NOT venous)
Hydralazine Indication
DOC pregnancy induced hypertensive emergencies related to eclampsia
Hydralazine PK
Oral or IV
Hydralazine Adverse
HA, tachycardia, nausea, sweating, flushing
Lupus like syndrome
Reflex tachycardia and fluid retention
Volume overload -> edema and CHF
Minoxidil (Rogaine) class
direct vasodilator
Minoxidil (Rogaine) description
Never 1st line treatment
Direct acting smooth muscle relaxant
Reflex tachycardia, increased plasma renin ->Sodium and water retention
(coadmin with a diuretic and betablocker)
Minoxidil (Rogaine) mechanism
Opening of Potassium channels in smooth muscle -> arteriolar dilation (NOT venous)
Minoxidil (Rogaine) Indication
Severe malignant HTN
Male pattern baldness (hypertrichosis)
Minoxidil (Rogaine) Adverse
HA, tachycardia, nausea, sweating, flushing
Reflex tachycardia and fluid retention
Volume overload -> edema and CHF
Bosentan class
Non selective endothelin receptor blocker
Bosentan description
Blocks the endothelin mediated (ETa and ETb) vasoconstriction
Bosentan contraindications
PREGNANCY CATEGORY X
Epoprostenol description
synthetic PGI2
Epoprostenol mechanism
Lowers peripheral, pulmonary and coronary resistance
Bosentan indication
Pulmonary HTN
Epoprostenol indication
Pulmonary HTN
Epoprostenol PK
continuous IV infusion
Epoprostenol Adverse
Flushing, HA, JAW PAIN, diarrhea, arthralgia
Typical 1st line treatment
ACE-I’s ARB’s
1st line in patients with acute or chronic CAD
ACE-I’s, or ARB’s and add Beta blocker
Patients with LV dysfunction first line treatment
Thiazide or loop diuretic and beta blocker along with ACE-I or ARB (plus hydralazine and isosorbide dinitrate if black)
HTN treatment for MI patients
Begin on beta blocker before adding ACE-I or ARB
HTN treatment for patients who have a history of ischemic stroke
Get an ACE-I or ARB and a thiazide diuretic