Cardiovascular Flashcards
Quinidine mechanism of action
Blocks fast Na channels in open or active state
Increases Action potential duration and effective refractory period
Blocks K channels causing prolonged repolarization
Muscarinic receptor blockade which can increase HR and AV conduction
Vasodilation via Alpha block and possible reflex tachycardia
Quinidine used for
Orally effective used for many arrhythmias and atrial fibrillation
Need INITIAL DIGITALIZATION to slow AV conduction
Quinidine adverse affects
1) Cinchonism (GI, tinnitus, ocular dysfunction, CNS excitation)
2) Hypotension
3) Prolongation of QRS and increase in QT interval associated with Syncope (torsades)
4) Black water Fever
Quinidine drug interactions
Hyper K enhances effects and Hypo K decreases affects
Displaces Digoxin from tissue binding sites enhancing toxicity
Procainamide mechanism of action
Blocks fast Na channels that are open or activated
Incarease action potential duration and effective refractory period
Blocks K channels
Has less Muscarinic receptor block
Metabolized via N-acetyltransferase to N-acetyl procainamide, an active metabolite
Procainamide used for
Antiarrhythmia
Procainamide adverse affects
SLE - like syndrome in slow acetylators
Hematotoxicity causing thrombocytopenia and agranulocytosis
Torsades
Class 1A antiarrythmics drugs
1) Quinidine
2) Procainamide
Class 1A antiarrhythmics MOD
1) block fast, active Na Channels
2) Block K channels
3) Some Muscarinic receptor blockade
Increases APD and ERP
Affect Phase 0
Disopyramide action
Class 1A antiarrythmic with the most M blockade
Not used for arterial arrythmia
Used for VENTRICULAR arrhythmia
Drugs that cause SLE- like disease
1) Procainamide
2) Isoniazid
3) Hydralazine
Lidocaine mechanism of action
Block fast Na channels in inactivated state (damaged tissue)
Decrease APD due to block of SLOW Na “window” currents - increases diastole and extends the time for recovery
Give in IV to prevent First Pass metabolism
Lidocaine used for
Arrythmias due to:
1) post MI
2) Open-heart surgery
3) Digoxin toxicity
Lidocaine adverse affects
CNS toxicity causing seizures
Mexiletine mechanism of action
Blocks fast Na channels in inactivated state
Given orally
Same as Lidocaine
Tocainide mechanism of action
Blocks fast inactivated Na channels
Same as Lidocaine
Given orally
Tocainide adverse affects
can lead to agranulocytosis and decrease on other blood cells
Class 1B drugs
Lidocaine
Mexiletine
Tocainide
Class 1B drugs Mechanism of action
Blocks fast, inactivated Na channels
Blocks slow Na channels
Found in Ischemic tissue
Flecainide mechanism of action
Blocks fast Na channels in His-Purkinje tissue
Has no effect on APD
No ANS effect
Flecainide adverse affects
can cause sudden death post MI
Class 2 drugs
Beta blockers:
1) Propranolol (B1=B2)
2) acebutolol (B1)
3) Esmolol (B1 short acting for SVT)
Class 2 antiarrythmics mechanism of action
Prevent Beta receptor activation decreasing cAMP
Decrease SA and AV nodal activity
Decrease slope of phase 4 (diastolic current) in AP in Pacemaker
Amiodarone mechanism of action
Decreases K channel slowing phase 3 (repolarization) of AP
Increase APD and ERP
Mimics class 1, 2, 3, and 4 antiarrythmics
Large VD and multiple effects
Amiodarone adverse affects
1) Pulmonary fibrosis
2) blue pigmentation of the skin (Smurf Skin)
3) Phototoxicity
4) Corneal deposits
5) Hepatic necrosis
6) Thyroid dysfunction
Sotalol mechanism of action
Decrease conductance of K channels slowing phase 3
Non - selective Beta blockade - Beta 1 leading to decrease HR, AV conduction
Sotalol adverse affects
Torsades (the worst)
Class 3 drus
Amiodarone
Sotalol
Class 3 mechanism of action
Block K channels decrease phase 3
Verapamil and diltiazem mechanism of action
Class 4 antiarrythmics that block Ca Channels
Decrease phae 0 and phase 4
Decrease SA and AV nodal activity
Verapamil adverse affects
1) consitpation
2) dizziness
3) flushing
4) hypotension
5) AV block
6) Gingival hypoplasia
Diltiazem adverse affects
Same as Verapamil minus constipation
Class 4 drugs
Verapamil and Diltiazem
Ca blocks
Class 4 antiarrythmic drug interactions
Additive AV block with Beta blockers and Digoxin
Verapamil displaces Digoxin from tissue-binding sites, increasing Digoxin toxicity
How to treat Torsades
1) Control HypoK
2) Correct HypoMg
3) Discontinue drug causing prolonged QT
4) attempt to shorten APD with Isoproterenol or electrical paceing
Drugs causing QT prolongation (Torsades)
Class 1A and Class 3 drugs
Thioridazine
TCA
Adenosine Action
Causes Gi coupled decrease in cAMP
Decrease SA and AV nodal activity
Adenosine is DOC for
Paroxysmal supraventricular tachycardia
AV nodal arrhythmia
Adenosine adverse affects
1) Flushing
2) Sedation
3) Dyspnea
Adenosine interaction with Methylxanthines
Methyxanthines are Theophylline and caffeine
Adenosine antagonized by Methylxanthines
Methylxanthines will decrease affect of Adenosine
Stratagey for antihypertensives
Decrease TPR - CCB
Decrease CO - Beta blockers, CCB
Decrease body fluids - Diuretics, ACEI, ARB
Decrease BP
Clonodine and Methyldopa Mechanism of action
Alpha 2 agonist that decreases sympathetic outflow
Decreases TPR and HR
Clonodine used for
Mild to moderate hypertension
Opiate withdrawl
Methyldopa used for
Mild to moderate HT
Hypertensive managment in pregnancy
Issue with Clonodine
Can lead to MASSIVE rebound HT if stopped
Reserpine mechanism of action
Decreases presynamptic storage levels decreasing CO and TPR because of decreased Norepi, Dopamine and serotonin in CNS
Reserpine adverse affects
Depression (severe leading to suicide)
Edema
Increase GI secretion
Guanethidine mechanism of action
Inhibit NE release
Adverse affects of Alpha 1 blockers used for HT
1) First dose syncope (sudden fall of BP)
2) Orthostatic Hypotension
3) Urinary incontinence
Advantages of using Alpha 1 blockers for HT
Good for HT and BPH
Increase HDL and Decrease LDL
Adverse affects of using Beta blockers in HT
1) CVS depression
2) Fatigue
3) Sexual dysfunction
4) Increase LDL and TG
5) mask DM
Hydralazine mechanism of action
1 for preganancy induced HT
Decrease TPR via arteriolar dilation
Acts through Nitric Oxide
Hydralazine adverse affects
1) SLE like syndrome in Slow Acetylators
2) Edema
3) Reflex Tachycardia
Nitroprusside Mechanism of action
Decrease TPR via dilation of both arterioles and venules
DOC for Hypertensive emergencies via IV
Acting through Nitric oxide
Nitroprusside adverse affects
Causes cyanide toxicity when co-administered with nitrites and thiosulfates
Minoxidil mechanism of action
Opens K channels causing HYPERPOLARIZATION of smooth muscle results in ARTERIOLAR vasodilation
Minoxidil used for
1) severe HT
2) Baldness
Diazoxide mechanism of action
Opens K channels causing HYPERPOLARIZATION of smooth muscles reults in arteriolar vasodilation
Diazoxide used for
Hypertensive emergencies
Adverse affects of Minoxidil
1) Hypertrichosis (Hirsturism)
2) Edema
3) Reflex tachycardia
Adverse affects of Diazoxide
1) hyperglycemia (decrease insulin release)
2) Edema
3) reflex tachycardia
Captopril (-Prils) mechanism of action
ACE inhibitors
Block formation of AT 2 resulting in prevention of AT1 - receptor stimulation
Decrease aldosterone and vasodilation
Losartan (-Sartan) mechanism of action
ARB
Blocks AT1 receptors
Same result as ACEIs on BP mechanisms
Aliskiren mechanism of action
Directly inhibit Renin
ACEI, ARB and Aliskiren used for
Mild eot moderate HT
Protective of Diabetic nephropathy (ACEI and ARBS)
CHF (ACEI adn ARBS)
ACEI, ARB, and Aliskiren Adverse affects
1) Dry cough (ACEI)
2) HyperK
3) Acute renal artery stenosis
4) Angioadema
PT has HT with Angina give:
Beta blockers and CCB
PT has HT and Diabetes give
ACEIs and ARBs
PT has HT and HF give
ACEIs, ARBs, and Beta blockers
PT has HT and post MI give
Beta Blocker
PT has HT and BPH give
Alpha 1 selective blocker
PT has HT and Dyslipidemia give
Alpha blocker, CCBs, ACEIs/ARBs
Bosentan mechanism of action
Endothelin - 1 receptor antagonist inhibiting ETA action of vasoconstriction Used for pulmonary HT
Bosentan adverse affects
Headache, flushing, hypotension and is contraindicated in pregnancy
Epoprostenol mechansim of action and use
Prostacyclin (PGI2) analog
Used via infusion pump to treat pulmonary HT
Sildenafil mechanism of action
Inhibits type V PDE and increases cGMP causing pulmonary artery relaxation and decreases pulmonary HT
Goal for treating HF
- Decrease preload: Diuretics, ACEI, ARB, venodilators
- Decrease afterload: ACEI, ARB, arteriodilators
- Increase contractility: Digoxin, beta agonist
- Decrease remodeling of cardiac muscle: ACEI, ARB, spironolactone, beta blockers
Digoxin mechanism of action
Inhibition of cardiac Na/K ATPase cuases increas intracellular Na.
Increase in Na decreases Na/Ca exchange causing an increase in intracellular Ca resulting in increase Ca release from Sarcoplasmic reticulum.
Increase in Ca causes increase actin-myosin interaction and increase in contractile force
Also, increase vagal activity resulting in parasympathetic actions
Digoxin pharmacokinetics
Long t 1/2: needs LD
Cleared by kidneys so take caution in renal failure
Large VD because it binds to tissue, caution in displacement via Verapamil and quinidine
Digoxin adverse affects
- Anorexia, nausea
- Prolonged PR
- Shortened PT
- Depressed ST or inverted Twave
- Visual defects, halos
- In toxic doses causes: Arrhythmia and heart block
Inamrinone and milrinone mechanism of action
Phosphodiesterase inhibitors causing Increase in cAMP in heart muslce resulting int increase inotropy and increase cAMP in smooth muscle resulting in decrease TPR
Ranolazine mechanism of action
Blocks late inward Na current in cardiac myocytes causing decrease in Ca accumulation resulting in decreased end diastolic pressure and improvement of diastolic coronary flow
Ranolazine adverse affects
- Constipation and nausea
- Increased QT
Acetazolamide mechanism of action
Carbonic Anhydrase inhibitor resulting in:
- Decrease H formation inside PCT
- Decrease Na/H antiport
- Increase Na dn HCO3 in lumen
- Increase Diuresis
Acetazolamide used for
Galucoma, Acute mountain sickness, Metabolic Alkalosis
Acetazolamide adverse affects
- Bicaronaturia and acidosis
- HypoK
- HyperCl
- Paresthesias
- Renal stones
- Sulonamide hypersensitivity
Dorzolamide is
Similar to Acetazolamide a CA inhibitor Used Topically for Glaucoma
Furosemide mechanism of action
Loop diuretic inhibiting Na/K/Cl transporter in TAL resulting in:
- Decrease intracellular K in TAL
- Decrease back diffusion of K
- Decrease positive potential
- Decrease reabsorption of Ca and Mg
- Increase diuresis
Furosemide used for
- Acutue pulomnary edema
- HF
- HT
- Refractory edema
- Acute renal faiulre
- Anion overdose
- HyperCa states
Ethacrynic acid is
A loop diuretic similar to furosemide with out the sulfonamide allergic reaction. However, causes irreversible ototoxicity
Drugs with sulfa allergies
- CA inhibitors
- Furosemide
- Thiazides
- Sulfa antibiotics
- Celecoxib
Furosemide adverse affects
- Sulfa reaction
- HypoK and Alkalosis
- HypoCa - can cause renal Ca stones
- HypoMg
- Hyperuricemia
Furosimede drug interactions
Lithium decreases clearance.
Digoxin in toxicity due to electrolyte disturbances
Thiazide mechanism of action
Na/Cl transporter inhibition in DCT resulting in:
- Increase luminal Na and Cl
- Increase diuresis
Thiazides used for
- HT and CHF
- Calcium kidney stones
- Nephrogenic DI
Thiazide adverse affects
- Sulfa reaction
- HypoK and Alkalosis
- HyperCa
- Hyperuricemia
- Hyperglycemia
- Hyperlipidemia
Indapamide is
A thiazide that does not cause Hyperlipidemia
Spironolactone mechanism of action
K-sparing diuretic that inhibits aldosterone receptors in the basolateral side of Collecting tubules. Causes increase K and decrease Na
Spironolactone used for
- Hyperaldosteronic sstate
- Adujunt to K-wasting
- Antiandorgenic uses (female hisutism)
- CHF
Spironolactone adverse affects
HyperK and Acidosis
Antiandrogen
Eplerenone is
A K-sparing that is selective aldosterone receptor blocker
Amiloride and mechanism of action
Na channel blocker in the luminal area of Collecting tubules
Triamterene is
Na channel blocker like amiloride
Amiloride used for
K sparing
Lithium induced nephrogenic DI
Amiloride adverse affects
HyperK and Acidosis
Acetazolamide Urinary Electrolytes
- Increase in Na
- Increase in K
- Double increase in HCO
Resulting in Blood ACIDOSIS
Furosemide Urinary Electrolytes
- Double increase in Na
- Increase in K
- Increase in Ca
- Increase in Mg
- Increase in Cl
Resulting in Blood ALKALOSIS
Thiazide Urinary Electrolytes
- Increase in Na
- Increase K
- Increase Cl
- Decrease Ca
Resulting in blood ALKALOSIS
K-sparing Urinary Electrolytes
- Small Increase in Na
- Decrease in K
Resulting in Blood ACIDOSIS
Lovastatin (-Statins) mechanism of action
HMG-CoA reductase inhibition results in:
- Decrease liver cholesterol
- Increase LDL receptor expression
- Decrease plasma LDL
- Decrease VLDL synthesis causing Decrease Triglyceridemia
Inhibits conversion of HMC CoA to Mevalonic acid then cholesterol
Lovastatin adverse affects
- Myalgia, Myopathy (check creatine kinase)
- Rhabdomyolysis (increase with Gemfibrozil)
- Hepatotoxicity (check liver enzymes)
Cholestyramine mechanism of action
Complexation of bile salts in the gut results in:
- Decrease enterohepatic recirculation of bile salts
- Increase synthesis of new bile salts by the liver
- Decrease liver cholesterol
- Increase LDL receptor expression
- Decrease blood LDL
Colestipol is
Same as cholestyramine a bile acid inhibitor
Cholestyramine adverse affects
- Increase VLDL and Triglycerides (contraindicated in Hypertriglyceridemia)
- GI disturbance (steatorrhea)
- Vit malabsorption
Niacin (Vit B3) mechanism of aciton
Inhibits VLDL synthesis resulting in:
- Decrease plasma VLDL
- Decrease plasma LDL
- Increase plasma HDL
Niacin (Vit B3) adverse affects
- Flusing, pruritus, burning pain (use asprin)
- Hepatotoxicity
Gemfibrozil mechanism of action
Fibrate that bind to PPARalpha and increase expression of lipoprotein lipase resulting in:
- Decrease VLDL and IDL
- Modest decrease in LDL
- Increase in HDL
Fenofibrate is
Same as gemfibrozil a fibrate
Gemfibrozil adverse affects
Cholesterol Gallstones
Myositis
Ezetimibe mechanism of action
Prevents intestinal absorption of cholesterol resulting in Decrease in LDL
Antihyperlipidemics that are used when there is an increase in cholesterol
- Cholestyramine
- Colestipol
- Ezetimibe
Antihyperlipidemic used when there is increase TG
- Gemfibrozil
- Fenofibrate
Antihyperlipidemics used when there is increas in Cholesterol and TG
- Statins
- Niacin
- Ezetimibe
Orlistat mechanism of action
Inhibits pancreatic lipase leading to decreas triglyceride breakdown in intestines