Cardiac Pharmacology

Question 1

What are the five main categories (and subcategories) of cardiac drugs?

Answer 1

• Arrhythmia
• Angina
• Hypertension
• Lipids
• Thrombolytic
  (autonomic, VWs, glycoside)
  (symptomatic, prevention)
  (RAAS & ABCD, endothelial)
  (statins, fibrates, bile acid resins, ezetimbe)
  (vit K/warfarin, heparin/DOACs, TXA2/P2Y12, GIIb/IIIa and Prostanol, fibrinolysis)

Question 2

Describe the drug categories used for arrhythmia (1/5).

Answer 2

• Autonomic (beta agonists, muscarinic antagonists)
• Vaughn-Williams
• Glycoside (digoxin)

Question 3

Describe the drugs, mechanisms, and side effects of the Vaughn-Williams classification. (1/5)

Answer 3

• I a, b, c (Na blockers - lidocaine and flecanide)
• II (B-blockers. BALD FISH side effects)
• III (K blockers - amiodarone (7 P’s) and sotalol)
• IV (CCBs - verapamil, amlodipine, diltiazem - SHED the GAPS)
  Bradycardia, Arrythmia, Limbs cold, Disturbs glucose, Fatigue, Insomnia, Sexual disfunction, Hypotension
  Photosensitive rash, pigment (blue), peripheral hypothyroidism, peripheral neuropathy, prolongs QT interval, first Pass (hepatotoxicity), Pulmonary fibrosis
  SoB, headache, edema, dizziness, GI upset, angina, palpitation, sleepiness

Question 4

Describe the mechanism and side effects of digoxin (a glycoside). (1/5)

Answer 4

Na/K ATPase inhibitor - increases force, slows AVN conduction.
iBACK - indigestion (GI symptoms), bradycardia, AVN block, Confusion, K low

Question 5

Anti-anginal drugs are split into two types - symptomatic and prevention. Symptomatic drugs are covered previously, but briefly recap them here. (2/5)

Answer 5

GTN (activates NO to cause vasodilation. Causes dizziness and hypotension)
B-blockers: BALD FISH
CCB: SHED the GAPS

Question 6

Describe the three types of prevention drugs in angina. This includes mechanism and side effects. (2/5)

Answer 6

• HCN inhibitor (ivabradine - blocks If current - bradycardia, blurred vision)
• K activator (minoxidil and nicorandil - vasodilates with NO - neuro (flushing, dizziness, headache), ulcers, hirsutism)
• Late Na blocker (ranolazine - reduces force not affecting rate - i.e. opposite digoxin)

Question 7

Describe the RAAS and ABCD category of hypertensive drugs. This includes drugs, mechanism, and side effects. B and C are dealt with elsewhere. (3/5)

Answer 7

Renin antagonist (alskrilen - diarrhoea, renal failure, not in diabetes)
ACEi (ramipril, captopril - side effects CAPTOPRIL - cough, angioedema, potassium up, taste change, orthostatic hypotension, proteinuria, rash, increase in renin, low BP)
Diuretics:
- loop (ascending loop of Henle Na/K/2Cl - furosemide and bumetanide) and thiazide (distal tubule Na/Cl - bendroflumethazide). Both cause low electrolytes, BP, and gout
- K-sparing (aldosterone antagonist - spironolactone and eplerenone - oestrogen symptoms)

Question 8

Describe the endothelial category of anti-hypertensive drugs. These are additional and for resistive cases. (3/5)

Answer 8

Endothelin antagonists (bosentan etc. - used for pulmonary hypertension)
NO activator (nitroprusside)
Alpha inhibitor (doxazosin)

Question 9

Hydralazine is an alternative to ACEi used for hypertension. Describe its mechanism, side effects, and indications. (3/5)

Answer 9

Increases Ca2+ intracellularly, reducing afterload.
Flush, tachy, palpitation, fluid retention, headache, drug induced lupus
In Africans (+ nitrate) or severe pregnant hypertension

Question 10

Neprilysin inhibitors are the only drugs used in heart failure not discussed elsewhere. Describe the drug and its side effects.

Answer 10

Sacubitril/valsartan

Hypotension, hyperkalaemia, renal impairment

Question 11

Describe statins. Their mechanism of action also helps describe their side effects. (4/5)

Answer 11

Inhibits HMG-CoA reductase, upregulating intake of cholesterol into liver cells.
S/E: HMG-CoA RI:
Hepatotoxicity, Myositis, GI upset, Can’t sleep, Angio-oedema, Rhabdomyolysis, Increase risk diabetes

Question 12

Describe the main drugs used to lower cholesterol apart from statins. This includes mechanism and side effects. (4/5)

Answer 12

Fibrates - decreases VLDL and enhance LPL. s/e include rhabdomyolysis, GI upset, pruritis and rash
Bile acid binding resins (cholestyramine) - diarrhoea
Ezetimibe (NPC1L1 inhibitor - prevents cholesterol absorption in duodenum)

Question 13

Describe the main anti-coagulant drugs (vitamin K/warfarin, Heparin/LMWH/DOACs). Focus on names and mechanism, with the main side effect. (5/5)

Answer 13

Vitamin K - forms II, VII, IX, and X
Warfarin - vitamin K epoxide reductase inhibitor. Many different side effects and interactions
Heparin (UFH) - activates antithrombin III by blocking thrombin (IIa and Xa)
LMWHs - enoxaparin, dalteparin, fondaparinux, blocks Xa
DOACs - dabigatran, rivaroxaban, apixaban. Can be used instead of warfarin

Question 14

Describe the anti-thrombotic drugs used acutely in ACS (aspirin, adenosine inhibitors, and thrombolytics). (5/5)

Answer 14

Aspirin - binds COX-1 to prevent TXA2 synthesis. 300mg acute and 75mg prophylaxis. May result in GI bleed
Adenosine inhibitors - clopidogrel, ticagrelor, prasugrel - block P2Y12 receptors on platelets
Fibrinolytic drugs - streptokinase + ‘plase - activates plasmin from plasminogen degrading clot. Used when PCI time > 120 min