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CVS Pharmacology - Coggle Diagram
CVS Pharmacology
CHF
Diuretics
Loop diuretic - Furosemide
Inhibits water resorption - Loop of Henle
Block ion transporters
Prevent Na+, K+, 2Cl- reabsorption
Side effects
Electrostatically imbalanced
Hypokalemia
Resistance - rotate drug
"K+ sparing" diuretic
Inhibits aldosterone action at DCT
Prevent Na+ reabsorption
K+ retained
Spironolactone
:arrow_down: effectiveness , :red_cross: hypokalemia
Thiazide
Inhibit Na+ and Cl- resorption at DCT
Electrostatically balanced
Reduce preload
Carbonic anhydrase inhibitor
Inhibits carbonic acid resorption
--> CO2 + H2O
+ve inotrope
Drug types
Amrinone; milrinone (IV)
Methylxantines
Bronchodilator
Inodilator
Vasodilation
Inhibit CAMP
Cellular energy source in arteries
Pimobendan
Indications
B2
Cardiac enlargement without CHF signs
C
Treatable signs of CHF
Angiotensin-associated
Drugs
Types
Angiotensin converting enzyme inhibitor (ACE-I)
Prevents conversion of Ang1--> 2
Angiotensin receptor blocker (ARB)
Inhibit vasoconstriction on arterioles
Effects
:red_cross: aldosterone secretion
:arrow_down: Na+ + :droplet: absorption
:red_cross: systemic vasoconstriction
:arrow_down: BP + afterload
:arrow_down: GFR
:arrow_down: efferent arteriole constriction+tone
Hydrostatic pressure
Mild azotaemia ; hyperkalemia ; systemic hypotension
Treat proteinuria
:arrow_down: Further basement membrane damage
A1 receptor agonist
Vasoconstriction of arteries + arterioles
Non-specific
+Stimulate B1/B2 receptors
Efficacy: noradenaline > adrenaline
Direct cardiac effect [Cardiac emergencies]
+ve Inotrope
Mechanism
:arrow_up: intracellular [Ca2+]
:arrow_up: myofibril contraction
:arrow_up: myofilaments Ca sensitivity
Expose actin sites --> myosin binding
Inodilator: Pimobendan (Vetmedin, Cardisure)
Routes
Oral solution, tablets, IV inj
Phosphodiesterase inhibitor
Inhibit cAMP - cellular energy source
Arterial vasodilation
Indications
Chronic dilated cardiomyopathy
Myxomatous mitral valvular disease
Others
Amrinone; milrinone (IV)
Methylxantines (chocolate) - theobromine
Antiarrhythmic drugs
Block cardiac ion channels
Myocyte cell membranes
:arrow_down: electrical conductivity
Na+, K+, Ca2+
Class categories
Ventricular
1 : block Na+ channels
Membrane stabilisers
Local anaesthetic agents eg. lignocaine
3: Block K+ channels
+/- B blocker
Supraventricular
2: B AR blockers
4: Block Myocyte Ca2+ channel
Atrial fibrillation
5: Cardiac glycoside - digoxin
+supraventricular ARs
Indications
Cardiac dysrhythmias (arrhythmias)
Causes
Digoxin
High dose of adrenaline
Idiopathic
Intrinsic myocardium damage
Eg. ischaemia; hypoxia
Restore adequate circulation / pulse
Treat underlying disease
Normal CO
Complications
Worsen arrhythmia
-ve inotrope action
Muscarinic receptor antagonist
Counter cholinesterase inhibitors
Eg. Atrophine
Acute brachycardia
Short acting
Eg. Opiod-induced
M2
M2 receptors at SA node
B1 adrenoreceptor
B1 adrenoreceptor antagonist [-ve inotrope]
Class 2 antiarrhythmic agent
Propranolol (non-selective) ; atenolol (B1 selective blocker)
:arrow_down: force of contraction
:arrow_down: BP - hypotensive
Counteract :arrow_up: cardiac sympathetic stimulation
Hypertrophic cardiomyopathy
:arrow_down: ventricular contraction force
Hyperthyroidism :cat2: ; chocolate toxicity :dog2:
Functional adrenal medulla tumours
CNS excitability / anxiety
Mediated by dopamine + noradrenaline
B1 adrenoreceptor agonist [+ve inotrope]
Selective
Constant rate infusion
Dopamine; dobutamine
Maintain HR
Post cardiac arrest
Non-selective
Efficacy: Isoprenaline > Noradrenaline > adrenaline
Acute cardiac arrest