Pharmacology General Flashcards
(96 cards)
Define Chronotrope
Agent that affects heart rate
(+) increases HR and (-) decreases HR
Define Inotrope
Agent that affects myocardial contractility
(+) increases contractility
(-) decreases contractility
Define Inotrope
Agent that affects rate of conduction
(+) increases conduction rate
(-) decreases conduction rate
What action do Vasoactive drugs have?
Agents that effect the vessel tone
What action do Vasopressors have?
Agent that causes vasoconstriction, increasing systemic vascular resistance.
TDLR; Increase BP
What mechanism of action does: Catecholamine have?
Depends where they bind
sympathomimeteic action; similar to vasopressors
Increases (response to stimuli/stress)
- HR, BP, metabolic rate
- Vasodilation or vasoconstriction
- Regulation of mood/behaviour
- Regulation of Metabolic process
Which drug group are direct-acting?
aka have a mimicking or modifying affect?
Muscarinic receptor agonists
which drug group inhibits and is indirect-acting?
acetylcholinesterase inhibitors
(ach)
Agonist vs Antagonist drugs?
Agonist drugs: STIMULATE
- bind to receptor; producing/stimulating a response via chemical or receptor
Antagonist drugs: STOP
- bind to the receptor on the primary site which stops the receptor from producing a response
where are a-adrenergic receptors located
- What is their function?
Located in the peripheral vasculature
Regulate smooth muscle tone
Which neurotransmitters bind to a-adrenergic receptor sites?
Sympathetic: Norepinephrine and epinephrine.
Where are B-adrenergic receptors found?
Airways and Cardiac muscles
what function do B-andrenergic receptors have?
Inhibitory for airways
Excitatory for cardiac muscles
What are the 2 subtypes for B-adrenergic receptors?
B1 and B2
what does B-1 adrenergic receptors agonist stimulation do?
Excites.
- Increases heart rate
- myocardial contractility
- rate of conduction.
In the heart.
what does B2 adrenergic receptors agonist stimulation do?
Relax/stop
Lungs and smooth muscles relax
via bronchodilation
what happens when Dopaminergic receptors cause agonal stimulation ?
Agonist stimulation causes vasodilation and increased blood flow to the cerebral coronary and renal vascular beds
Where are dopaminergic receptors located?
Smooth muscle cells in the cerebral coronary and renal vascular beds
Function of Epinephrine (adrenalin)?
Stimulation.
Both an A and B agonist.
Combo of vasopressor, inotropic, chronotropic, and domotropic properties.
When would you use epinephrine?
Cardiac arrest: initial does 1mg (1:10,000 sol’n), repeat every 3-5 mins.
pulseless arrhythmias:
-Ventricular tachycardia
-V Fib
-PEA asystole
Why is epinephrine used for cardiac arrest?
increases both coronary and cerebral perfusion pressure (CPP) pressures
What is Cerebral perfusion pressure (CPP)
Pressure gradient causing cerebral blood flow to the brain.
must be maintained within narrow limits:
-Too little = brain tissue to become ischemic.
-Ttoo much = raised intracranial pressure.
why would you want a Hypotension action from epinephrine?
Anaphylaxis or severe allergic reactions.
its an infusion admin’d SQ or IM
Norepinephrine (NE) is also referred to as
Levophed
A powerful a and B1 receptor agonist.