Lecture Course 3: Cardio And Renal

Question 0

Flecainide

Answer 0

Na channel blocker.
Class IC antidysrythmic.
No effect on AP but very slow association and dissociation.

Question 1

Spermine

Answer 1

Intracellular polyamide which acts as a valve in inward rectifying potassium channels.

Question 2

Amiodarone

Answer 2

Prolongs the cardiac AP and thus also the refractory period
Can block both inward Na and outward K - complex mechanism
Used for ventricular dysrhythmia

Question 3

Digoxin

Answer 3

Cardiac glycoside
Inhibit NaKATPase
[Ca]i ≈ Na³
Calcium extrusion reduced
Used in treatment of congestive heart failure.

Question 4

Digitoxin

Answer 4

Cardiac glycoside
Inhibit NaKATPase
Cai ≈ Na³
Calcium extrusion reduced
Used in treatment of congestive heart failure.

Question 5

Ouabain

Answer 5

Cardiac glycoside
Inhibit NaKATPase
Cai ≈ Na³
Calcium extrusion reduced
Too potent for use in treatment of congestive heart failure.

Question 6

Dobutamine

Answer 6

B1 agonist. Sympathomimetic agent.
Used in congestive heart failure, esp in shock. Intravenous.
Positive ionotropic effect but may also increase rate, and increases O2 demand
May cause dysrhythmia, potentiate hypertension, etc

Question 7

Bisoprolol

Answer 7

B1 antagonist

Used to treat heart failure

Question 8

Carvedilol

Answer 8

B1 blocker

Used to treat heart failure

Question 9

Milrinone

Answer 9

PDE type III inhibitor (potentiates cGMP)
Inodilator. May produce dysrhythmia.
Prevents cGMP breakdown which causes similar effects to b blockers
Vasodilation in smooth muscle

Question 10

Dipyridamole

Answer 10

PDE V inhibitor.
Raises intracellular cAMP
Used in treatment of heart failure

Also blocks transport of adenosine into cell, thus prolonging neurotransmitter action

Question 11

Caffeine

Answer 11

Methyxanthine.
Non selective PDE inhibitor
Increases intracellular calcium
A1 and A2 antagonists 
-> positive ionotropic and chronotrophic effects
May lead to dysrhythmia

Question 12

Theophylline

Answer 12

Methyxanthine.
Non selective PDE inhibitors
A1 and A2 antagonists 
-> positive ionotropic and chronotrophic effects
May lead to dysrhythmia

Question 13

Pimobendan

Answer 13

Inodilator - inhibits PDE III
‘calcium sensitiser’ - increases cardiac calcium binding efficiency without requiring greater energy
Used in treatment of canine dilated cardiomyopathy and mitral valve regurgitation, especially Dobermen!

Question 14

Levosimendan

Answer 14

Inodilator - inhibits PDE III
‘calcium sensitiser’ - increases cardiac calcium binding efficiency without requiring greater energy
Used in human medicine in other countries

Question 15

Streptokinase

Answer 15

Anti clot drug
Binds plasminogen activator to activate Plasmin
Plasmin inhibits factor 7, 5 and Thrombin

Question 16

Plasmin

Answer 16

Serine protease, activated by anti clot drugs
Hydrolyses Arg-Lys bonds
Targets 7a, 5a, thrombin

Question 17

Anistreplase

Answer 17

Combination of plasminogen and anisoylated streptokinase
Streptokinase activates Plasmin
Anisoyl group removed in blood - prolonged activity
Anti clot drug

Question 18

Alteplase & duteplase

Answer 18

Recombinant human tissue plasminogen activator
Greater activity on plasminogen bound to fibrin clot -> localises action
Activates Plasmin - targets 7a, 5a, thrombin
Anti clot drug
Alteplase = single chain
Duteplase= double chain

Question 19

Aspirin

Answer 19

Prevents platelet aggregation/bridging by inhibiting ADP binding to platelets
Often used in this respect alongside Clopidogrel

Question 20

Clopidogrel

Answer 20

Inhibits platelet aggregation by inhibiting ADP binding to platelet receptor
Used in combination with aspirin

Question 21

Eptitibatide

Answer 21

Anti clot drug
Cyclic heptapeptide inhibitor
Inhibits glycoprotein IIb/IIIa which causes platelet aggregation in conjunction with fibrinogen

Question 22

Tirofiban

Answer 22

Anti clot drug
Non peptide inhibitor
Inhibits glycoprotein IIb/IIIa which causes platelet aggregation in conjunction with fibrinogen
Prevention of myocardial infarction in older patients

Question 23

Abciximab

Answer 23

Monoclonal antibody against vitronectin receptor on platelets, endothelial and vascular smooth muscle
Vitronectin involved in cell adhesion and haemostatis
Used with coronary angioplasty for coronary artery thrombosis

Question 24

*Heparin*

Answer 24

Endogenous/injectable Anticoagulant, produced by basophils and mast cells Binds antithrombin IIIA (ATII) to expose its active site Activated enzyme inactivates thrombin and Xa Treatment for DVT, myocardial infarction, unstable angina and as a prophylactic drug to prevent clots forming during surgery

Question 25

*Warfarin*

Answer 25

Oral anticoagulant Inhibits synthesis of thrombin, VII, IX, X and regulatory protein factors C, S, Z via enzyme ATII Also used to prevent clot formation on prosthetic heart valves Interacts with food and drink chemicals :/

Question 26

*Dabigatran*

Answer 26

New anticoagulant Thrombin inhibitor via ATII a Atrial fibrillation drug/short term prophylactic to prevent clotting in hip/knee replacement surgery

Question 27

River ouabain

Answer 27

Factor Xa inhibitor | Used in atrial fibrillation/temporary prophylactic

Question 28

*Aminocaproic acid or tranexamic acid*

Answer 28

Prevents severe bleeding during excessive clot lysis | Inhibits plasminogen activation

Question 29

*Acetazolamide*

Answer 29

Diuretic Carbonic anhydrase inhibitor - decrease NaHCO3- re absorption - > nateuresis Mostly obsolete as a diuretic, used to lower intraocular pressure in glaucoma

Question 30

*Mannitol*

Answer 30

Osmotic diuretic Small molecule that is filtered via the glomerular apparatus No reabsorption but retains osmotic pressure -> less H₂O efflux -> less Na efflux Maintains urine flow. Used acutely to treat cerebral oedema

Question 31

*Furosemide* and Bumetanide

Answer 31

Loop diuretics Fast acting: within an hour orally, within 10 minutes IV Venodilatory action precedes diuretic Blocks NaKCC in thick aLoH Powerful - 15-25% filtrate excretion Problems : Hypokalaemia and metabolic alkalosis Calcium and magnesium loss Uric acid excretion reduced ~> gout

Question 32

*hydrocholorothiazide* and bendroflumethazide

Answer 32

Thiazide diuretic Act in DCT by inhibiting NaCl cotransporter Problems: - hypokalaemia (do NOT combine with cardiac glycosides) and metabolic alkalosis - Uric acid excretion down (gout) - increases Mg excretion, decrease calcium excretion

Question 33

*amiloride* and *triamterene*

Answer 33

Potassium sparing diuretic Block apical sodium channels in late DCT, a major side of potassium loss Often combined with loop or thiazide diuretics