Drugs modifying cardiac rate and force Flashcards
Clinical uses of adrenaline
- rapid uptake
- cardiac arrest IV
- anaphylactic shock IM!!
Adrenaline pharmacodynamics?
positive inotropic and chronotropic actions (β1)
redistribution of blood flow to the heart (constricts blood vessels in the skin, mucosa and abdomen (α1))
dilation of coronary arteries (β2)
What is Dobutamine?
Stimulates B1 adrenceptors
Clinical use Dobutamine?
acute, but potentially reversible, heart failure
B-adrenoreceptor antagonists always target B1 receptors
FALSE
Can block both 1 and 2 or can be selective
What are B-adrenoreceptor antagonists used to treat?
- Atrial fibrillation Supraventricular tachycardia by delayeding conduction through AV node
- Angina
- Heart failure: low dose improved mortality
- Hypertension: not first line unless angina present
Adverse effects of Beta Blockers
Bronchospasm
Aggravation of cardiac failure: sympathetic drive driving force adequate CO in these patients
Bradycardia
Hypoglycaemia: in patients with poorly controlled diabetes glucose released due to B2 receptors
Fatigue: skeletal muscle perfusion controlled B2 receptors
Cold extremities: loss of 2-adrenoceptor mediated vasodilatation in cutaneous vessels
Clinical application of atropine?
First line in management of haemodynamically comrpomised bradycardia
Pharmacodynamic effects of atropine?
- inc HR
No effect BP
T/F
Effects digoxin dangerously enhanced by hypokalaemia
T
Clinical use of digoxin?
- Acute heart failure (IV)
- Heart failure with atrial fibrillation
Side effects digoxin?
excessive depression of AV node conduction (heart block)
propensity to cause arrhythmias
nause, vomiting, diarrhoea GI effects
distrubance colour vision
What is levosimendan?
Calcium sensitizer
How do calcium sensitizers work?
Binds to troponin C and sensitizes it to action of calcium
What is Levosimendan used to treat?
Acute decompensated heart failure (IV)
