Cardiovascular Medications Flashcards
Define an Inotrope
agents that increase myocardial contractility e.g dobutamine, adrenaline
define a vasopressor
agents that cause vasoconstriction leading to increased SVR (systemic vascular resistance) - + BP e.g. Noradrenaline, metaraminol
define chronotrope
agents that alters the HR. Can be positive (e.g. atropine) or negative (e.g. beta blockers)
define vasodilator
agents that cause dilation of the blood vessels by promoting the relaxation of vascular smooth muscle e.g. GTN
what do Alpha 1 receptors do and give a drug example.
- increase CO
- increase peripheral resistance
- cause vasoconstriction
- noradrenaline, dopamine, adrenaline
what do Alpha 2 receptors do?
- ## inhibits the release of endogenous norepinephrine leading to vasodilation
what do beta 1 receptors do?
-increase myocardial contractility, HR and CO.
what do Beta 2 Alpha 1 receptors do?
- cause vasodilation of bronchioles, peripheral and renal circulations
- decreases peripheral vascular resistance
what does dopaminergic receptors do?
-causes vasodilation - increases blood flow to renal and mesentery
what does Noradrenaline do?
Works on both Alpha 1 and Beta 1 receptors
Mechanism of action:
-Causes vasoconstriction of peripheral vessels
-↑ SVR
-Improves Blood pressure and organ perfusion
-Increases contractility and Heart rate
what are the indications of Noradrenaline?
Indications:
- Restore BP in acute hypotensive states, such as sepsis
- Target a mean arterial pressure (MAP) of 70mmHg to ensure adequate organ perfusion
what is the concentrations that noradrenaline come, what is the onset and duration time?
Concentration: 8mg/16mg/32mg in 100mls N/Saline
Onset 1-2 mins
Duration 1-2mins
what does Adrenaline do?
Mechanism of action:
-Acts on both the heart and lungs
-In the lungs causes bronchodilation
-Low doses act on B1 & B2 receptors = ^ HR & contractility - CO
-In high doses will further ^ Hr & contractility.
Also has Alpha 1 effects - causing vasoconstriction
what are the indications for Adrenaline?
Indications
-Cardiac arrest, bronchospasm, anaphylaxis, arrhythmias - VF, VT
First-line treatment in ALS
what is the standard dose of Adrenaline?
Standard dose 1mg/ml, make with NS 6mg (SS)
12mg (DS)/100ml
24mg (QS)/100ml
what does Metaraminol do?
Mechanism of action
- Vasoconstrictor - stimulates alpha effects – peripheral vasoconstriction - +BP & +SVR (afterload)
- Indirect effects on sympathetic nerve endings causing the release of endogenous noradrenaline
what are the indications for Metaraminol?
Indications
-Short term management of acute hypotension (can be administered peripherally)
what is the standard doses that metaraminol can come in?
Standard dose: 10mg/20mls or 20mg/40mls NaCl
(0.5mg/ml)
explain what a low dose of dopamine can do?
Low doses - dopaminergic effects (0.5-3mcg/kg/min)
Effects: Dilation of renal, mesenteric, cerebral & coronary blood vessels –renal perfusion & diuresis
explain what moderate doses of dopamine can do?
Moderate doses – Beta1 effect (4-8mcg/kg/min)
Effects: increase contractility – improved CO
explain what high doses of Dopamine can do?
High doses – Alpha effects (>10mcg/kg/min)
Effects: vasoconstriction
explain what Vasopressin drugs can do?
Also known as anti-diuretic hormone – regulate body’s retention of H2O
- Acts on V1, V2, V3 receptors
- At high doses it acts on smooth muscle receptors to cause peripheral vasoconstriction and increase SVR and BP
- Less potently acts on kidneys to promote water reabsorption
what are the indications for vasopressin drugs?
Indications:
-To increase BP in vasodilatory shock when low SVR persists despite fluid resuscitation and first-line vasopressor
what are some side effect that could be caused by using a vasopressor drug?
Side Effects:
- Myocardial, mesenteric or peripheral ischemia
- Hyponatraemia (due to water retention)
