Drugs and the Heart Flashcards
(Review) What is an agonist and antagonist?
Agonist - binds to receptor and has an effect on the cell
Antagonist - binds to receptor but has no effect on the cell
What is a cholinergic agonist?
Binds to and activates the muscarinic receptors
- elicits PNS effect on heart (slower HR)
- example: nicotine
What does an acetylcholinesterase inhibitor do?
Inhibits the enzyme acetylcholinesterase, which is supposed to break down acetylcholine
- therefore, ACh is not broken down and PNS is active for longer
What is the effect of Anticholinergics (cholinergic antagonist)?
- prevent Ach from binding to the muscarinic receptors
- prevent PNS activation
What is the effect of adrenergic agonists?
- bind to beta 1 adrenergic receptors (which are all GPCRs) which activates the SNS
- quickens HR
- example: EpiPen
What is the effect of adrenergic antagonists (Beta Blockers)?
- prevent epinephrine and norepinephrine from binding to adrenergic beta 1 receptors
- prevents heart rate from speeding up
- beta blockers usually end in -olol
What is bradycardia?
Condition where the heart is beating too slow
Difference between first generation and second generation beta blockers
First generation - non-selective as to which beta 1 adrenergic receptors it binds to in the body
Second generation - cardioselective
What is a heart Arrhythmia?
A condition where the heart is beating too slow (bradycardia), too quickly (tachycardia), or irregularly (fibrillation)
3 types of arrhythmias
- Supraventricular arrhythmias
- Ventricular arrhythmias
- Bradyarrhythmias
What are the two main reasons arrhythmias occur?
- issue generating action potentials
- issue conducting action potentials
3 main ways arrhythmias can be treated
- Beta blockers
- Channel Blockers (K, Ca, or Na)
- Pacemakers
