Cardiovascular - Pharmacology Flashcards

1
Q

Antihypertensive therapy

  • Primary (essential) hypertension
  • Hypertension with CHF
  • Hypertension with diabetes mellitus
A
  • Primary (essential) hypertension
    • Diuretics, ACE inhibitors, angiotensin II receptor blockers (ARBs), calcium channel blockers.
  • Hypertension with CHF
    • Diuretics, ACE inhibitors/ARBs, β-blockers (compensated CHF), aldosterone antagonists.
    • β-blockers must be used cautiously in decompensated CHF and are contraindicated in cardiogenic shock.
  • Hypertension with diabetes mellitus
    • ACE inhibitors/ARBs, calcium channel blockers, diuretics, β-blockers, α-blockers.
    • ACE inhibitors/ARBs are protective against diabetic nephropathy.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Calcium channel blockers

  • Examples
  • Mechanism
  • Clinical use
  • Toxicity
A
  • Examples
    • Amlodipine, nimodipine, nifedipine (dihydropyridine)
    • Diltiazem, verapamil (non-dihydropyridine).
  • Mechanism
    • Block voltage-dependent L-type calcium channels of cardiac and smooth muscle, thereby reduce muscle contractility.
    • Vascular smooth muscle
      • Amlodipine = nifedipine > diltiazem > verapamil.
    • Heart
      • Verapamil > diltiazem > amlodipine = nifedipine
      • Verapamil = ventricle
  • Clinical use
    • Dihydropyridine (except nimodipine): hypertension, angina (including Prinzmetal), Raynaud phenomenon.
    • Non-dihydropyridine: hypertension, angina, atrial fibrillation/flutter.
    • Nimodipine: subarachnoid hemorrhage (prevents cerebral vasospasm).
  • Toxicity
    • Cardiac depression, AV block, peripheral edema, flushing, dizziness, hyperprolactinemia, and constipation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Hydralazine

  • Mechanism
  • Clinical use
  • Toxicity
A
  • Mechanism
    • Increases cGMP –>Ž smooth muscle relaxation.
    • Vasodilates arterioles > veins
      • Afterload reduction.
  • Clinical use
    • Severe hypertension, CHF.
    • First-line therapy for hypertension in pregnancy, with methyldopa.
    • Frequently coadministered with a β-blocker to prevent reflex tachycardia.
  • Toxicity
    • Compensatory tachycardia (contraindicated in angina/CAD), fluid retention, nausea, headache, angina, Lupus-like syndrome.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Hypertensive emergency

  • Commonly used drugs
  • Nitroprusside
  • Fenoldopam
A
  • Commonly used drugs
    • Nitroprusside, nicardipine, clevidipine, labetalol, and fenoldopam.
  • Nitroprusside
    • Short acting
    • Increases cGMP via direct release of NO.
    • Can cause cyanide toxicity (releases cyanide).
  • Fenoldopam
    • Dopamine D1 receptor agonist—coronary, peripheral, renal, and splanchnic vasodilation.
    • Decreases BP and increases natriuresis.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Nitroglycerin, isosorbide dinitrate

  • Mechanism
  • Clinical use
  • Toxicity
A
  • Mechanism
    • Vasodilate by increasing NO in vascular smooth muscle –> increase in cGMP and smooth muscle relaxation.
    • Dilate veins >> arteries.
    • Decreases preload.
  • Clinical use
    • Angina, acute coronary syndrome, pulmonary edema.
  • Toxicity
    • Reflex tachycardia (treat with β-blockers), hypotension, flushing, headache
    • “Monday disease” in industrial exposure: development of tolerance for the vasodilating action during the work week and loss of tolerance over the weekend results in tachycardia, dizziness, and headache upon reexposure.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Antianginal therapy

  • Goal
  • Calcium channel blockers
  • Pindolol and acebutolol
  • Nitrates
  • β-blockers
A
  • Goal
    • Reduction of myocardial O2 consumption (MVO2) by decreasing 1 or more of the determinants of MVO2: end-diastolic volume, blood pressure, heart rate, contractility.
  • Calcium channel blockers
    • Nifedipine is similar to nitrates in effect
    • Verapamil is similar to β-blockers in effect.
  • Pindolol and acebutolol
    • Partial β-agonists contraindicated in angina.
  • Nitrates
    • Affect preload.
  • β-blockers
    • Affect afterload.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Antianginal therapy

  • For each: increased, decreased, or little/no effect
    • Nitrates
    • β-blockers
    • Nitrates + β-blockers
  • End-diastolic volume
  • Blood pressure
  • Contractility
  • Heart rate
  • Ejection time
  • MVO2
A
  • End-diastolic volume
    • Nitrates: Decreased
    • β-blockers: Increased
    • Nitrates + β-blockers: No effect or decreased
  • Blood pressure
    • Nitrates: Decreased
    • β-blockers: Decreased
    • Nitrates + β-blockers: Decreased
  • Contractility
    • Nitrates: Increased (reflex response)
    • β-blockers: Decreased
    • Nitrates + β-blockers: Little/no effect
  • Heart rate
    • Nitrates: Increased (reflex response)
    • β-blockers: Decreased
    • Nitrates + β-blockers: Decreased
  • Ejection time
    • Nitrates: Decreased
    • β-blockers: Increased
    • Nitrates + β-blockers: Little/no effect
  • MVO2
    • Nitrates: Decreased
    • β-blockers: Decreased
    • Nitrates + β-blockers: Really decreased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Lipid-lowering agents:
HMG-CoA reductase inhibitors (lovastatin, pravastatin, simvastatin, atorvastatin, rosuvastatin)

  • Effect on LDL
  • Effect on HDL
  • Effect on triglycerides
  • Mechanisms of action
  • Side effects / problems
A
  • Effect on LDL (“bad cholesterol”)
    • Really really decreased
  • Effect on HDL (“good cholesterol”)
    • Increased
  • Effect on triglycerides
    • Decreased
  • Mechanisms of action
    • Inhibit conversion of HMG-CoA to mevalonate, a cholesterol precursor
  • Side effects / problems
    • Hepatotoxicity (increased LFTs), rhabdomyolysis (esp. when used with fibrates and niacin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Lipid-lowering agents:
Niacin (vitamin B3)

  • Effect on LDL
  • Effect on HDL
  • Effect on triglycerides
  • Mechanisms of action
  • Side effects / problems
A
  • Effect on LDL (“bad cholesterol”)
    • Really decreased
  • Effect on HDL (“good cholesterol”)
    • Really increased
  • Effect on triglycerides
    • Decreased
  • Mechanisms of action
    • Inhibits lipolysis in adipose tissue
    • Reduces hepatic VLDL synthesis
  • Side effects / problems
    • Red, flushed face, which is decreased by aspirin or long-term use
    • Hyperglycemia (acanthosis nigricans)
    • Hyperuricemia (exacerbates gout)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Lipid-lowering agents:
Bile acid resins (cholestyramine, colestipol, colesevelam)

  • Effect on LDL
  • Effect on HDL
  • Effect on triglycerides
  • Mechanisms of action
  • Side effects / problems
A
  • Effect on LDL (“bad cholesterol”)
    • Really decreased
  • Effect on HDL (“good cholesterol”)
    • Slightly increased
  • Effect on triglycerides
    • Slightly increased
  • Mechanisms of action
    • Prevent intestinal reabsorption of bile acids
    • Liver must use cholesterol to make more
  • Side effects / problems
    • Patients hate it—tastes bad and causes GI discomfort, decreased absorption of fat-soluble vitamins
    • Cholesterol gallstones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Lipid-lowering agents:
Cholesterol absorption blockers (ezetimibe)

  • Effect on LDL
  • Effect on HDL
  • Effect on triglycerides
  • Mechanisms of action
  • Side effects / problems
A
  • Effect on LDL (“bad cholesterol”)
    • Really decreased
  • Effect on HDL (“good cholesterol”)
    • No effect
  • Effect on triglycerides
    • No effect
  • Mechanisms of action
    • Prevent cholesterol absorption at small intestine brush border
  • Side effects / problems
    • Rare increased LFTs, diarrhea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Lipid-lowering agents:
Fibrates (gemfibrozil, clofibrate, bezafibrate, fenofibrate)

  • Effect on LDL
  • Effect on HDL
  • Effect on triglycerides
  • Mechanisms of action
  • Side effects / problems
A
  • Effect on LDL (“bad cholesterol”)
    • Decreased
  • Effect on HDL (“good cholesterol”)
    • Increased
  • Effect on triglycerides
    • Really really decreased
  • Mechanisms of action
    • Upregulate LPL –> increased TG clearance
    • Activates PPAR-α to induce HDL synthesis
  • Side effects / problems
    • Myositis (increased risk with concurrent statins), hepatotoxicity (increased LFTs), cholesterol gallstones (esp. with concurrent bile acid resins)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cardiac glycosides

  • Examples
  • Mechanism
  • Clinical use
  • Toxicity
  • Antidote
A
  • Examples
    • Digoxin
      • 75% bioavailability
      • 20–40% protein bound
      • t1/2 = 40 hours
      • Urinary excretion.
  • Mechanism
    • Direct inhibition of Na+/K+ ATPase leads to indirect inhibition of Na+/Ca2+ exchanger/antiport.
    • Increased [Ca2+]i –>Ž positive inotropy.
    • Stimulates vagus nerve –>Ž decreased HR.
  • Clinical use
    • CHF (increased contractility)
    • Atrial fibrillation (decreased conduction at AV node and depression of SA node).
  • Toxicity
    • Cholinergic—nausea, vomiting, diarrhea, blurry yellow vision (think Van Gogh).
    • ECG—increased PR, decreased QT, ST scooping, T-wave inversion, arrhythmia, AV block.
    • Can lead to hyperkalemia, which indicates poor prognosis.
    • Factors predisposing to toxicity—renal failure (decreased excretion), hypokalemia (permissive for digoxin binding at K+-binding site on Na+/K+ ATPase), verapamil, amiodarone, quinidine (decreased digoxin clearance; displaces digoxin from tissue-binding sites).
  • Antidote
    • Slowly normalize K+, cardiac pacer, anti-digoxin Fab fragments, Mg2+.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Antiarrhythmics—Na+ channel blockers (class I)

A
  • Slow or block (decrease) conduction (especially in depolarized cells). 
  • Decrease slope of phase 0 depolarization and increase threshold for firing in abnormal pacemaker cells.
  • Are state dependent (selectively depress tissue that is frequently depolarized [e.g., tachycardia]).
  • Hyperkalemia causes increased toxicity for all class I drugs.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Antiarrhythmics—Na+ channel blockers (class IA)

  • Examples
  • Mechanism
  • Clinical use
  • Toxicity
A
  • Examples
    • Quinidine, Procainamide, Disopyramide.
    • “The Queen Proclaims Diso’s pyramid.”
  • Mechanism
    • Increased AP duration, increased effective refractory period (ERP), increased QT interval.
  • Clinical use
    • Both atrial and ventricular arrhythmias, especially re-entrant and ectopic SVT and VT.
  • Toxicity
    • Cinchonism (headache, tinnitus with quinidine), reversible SLE-like syndrome (procainamide), heart failure (disopyramide), thrombocytopenia, torsades de pointes due to increased QT interval.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Antiarrhythmics—Na+ channel blockers (class IB)

  • Examples
  • Mechanism
  • Clinical use
  • Toxicity
A
  • Examples
    • Lidocaine, Mexiletine.
  • Mechanism
    • Decrease AP duration.
    • Preferentially affect ischemic or depolarized Purkinje and ventricular tissue.
    • Phenytoin can also fall into the IB category.
  • Clinical use
    • Acute ventricular arrhythmias (especially post-MI), digitalis-induced arrhythmias.
    • IB** is Best post-MI.**
  • Toxicity
    • CNS stimulation/depression, cardiovascular depression.
17
Q

Antiarrhythmics—Na+ channel blockers (class IC)

  • Examples
  • Mechanism
  • Clinical use
  • Toxicity
A
  • Examples
    • Flecainide, Propafenone.
    • Can I have Fries, Please.”
  • Mechanism
    • Significantly prolongs refractory period in AV node.
    • Minimal effect on AP duration.
  • Clinical use
    • SVTs, including atrial fibrillation.
    • Only as a last resort in refractory VT.
  • Toxicity
    • Proarrhythmic, especially post-MI (contraindicated).
    • IC** is Contraindicated in structural and ischemic heart disease.**
18
Q

Antiarrhythmics—β-blockers (class II)

  • Examples
  • Mechanism
  • Clinical use
  • Toxicity
A
  • Examples
    • Metoprolol, propranolol, esmolol, atenolol, timolol, carvedilol.
  • Mechanism
    • Decrease SA and AV nodal activity by decreasing cAMP, decreasing Ca2+ currents.
    • Suppress abnormal pacemakers by decreasing slope of phase 4.
    • AV node particularly sensitive—increased PR interval.
    • Esmolol very short acting.
  • Clinical use
    • SVT, slowing ventricular rate during atrial fibrillation and atrial flutter.
  • Toxicity
    • Impotence, exacerbation of COPD and asthma, cardiovascular effects (bradycardia, AV block, CHF), CNS effects (sedation, sleep alterations).
    • May mask the signs of hypoglycemia.
    • Metoprolol can cause dyslipidemia.
    • Propranolol can exacerbate vasospasm in Prinzmetal angina.
    • Contraindicated in cocaine users (risk of unopposed α-adrenergic receptor agonist activity).
    • Treat overdose with glucagon.
19
Q

Antiarrhythmics—K+ channel blockers (class III)

  • Examples
  • Mechanism
  • Clinical use
  • Toxicity
A
  • Examples
    • Amiodarone, Ibutilide, Dofetilide, Sotalol.
    • AIDS.”
  • Mechanism
    • Increase AP duration, increase ERP.
    • Used when other antiarrhythmics fail. 
    • Increase QT interval.
  • Clinical use
    • Atrial fibrillation, atrial flutter
    • Ventricular tachycardia (amiodarone, sotalol).
  • Toxicity
    • Sotalol—torsades de pointes, excessive β blockade.
    • Ibutilide—torsades de pointes.
    • Amiodarone—pulmonary fibrosis, hepatotoxicity, hypothyroidism/ hyperthyroidism (amiodarone is 40% iodine by weight), corneal deposits, skin deposits (blue/gray) resulting in photodermatitis, neurologic effects, constipation, cardiovascular effects (bradycardia, heart block, CHF).
    • Remember to check PFTs, LFTs, and TFTs when using amiodarone.
    • Amiodarone has class I, II, III, and IV effects and alters the lipid membrane.
20
Q

Antiarrhythmics—Ca2+ channel blockers (class IV)

  • Examples
  • Mechanism
  • Clinical use
  • Toxicity
A
  • Examples
    • Verapamil, diltiazem.
  • Mechanism
    • Decrease conduction velocity, increase ERP, increase PR interval.
  • Clinical use
    • Prevention of nodal arrhythmias (e.g., SVT), rate control in atrial fibrillation.
  • Toxicity
    • Constipation, flushing, edema, CV effects (CHF, AV block, sinus node depression).
21
Q

Other antiarrhythmics

  • Adenosine
  • Mg2+
A
  • Adenosine 
    • Increasing K+ out of cells Ž–> hyperpolarizing the cell and decreasing ICa.
    • Drug of choice in diagnosing/abolishing supraventricular tachycardia.
    • Very short acting (~ 15 sec).
    • Adverse effects include flushing, hypotension, chest pain.
    • Effects blocked by theophylline and caffeine.
  • Mg2+
    • Effective in torsades de pointes and digoxin toxicity.