Pharm Week 9: Drugs Affecting the cardiovascular system

based off brain boost

What is midodrine

a hypotensive agent

what is the action of midodrine?

activates alpha1- adrenergic receptor (agonist) → leading to peripheral vasoconstriction and an increase in vascular tone and blood pressure

what are the indications of midodrine?

treatment of orthostatic hypotension

midodrine can cause ___?

serious supine hypertension

what should you monitor in midodrine?

BP in the standing, sitting, and supine position

What are vasopressors?

used to lower BP

what are some examples of vasopressors?

norepinephrine, epinephrine, dopamine, phenylephrine

Where are infusions of vasopressors taken place?

intensive care unit (ICU) with frequent BP monitoring

What is heart failure?

a condition in which the heart fails to effectively pump blood throughout the body

What are the 2 contractile proteins in cardiac muscle?

Actin and myosin

what keeps actin and myosin apart?

troponin

what is the first goal in heart failure treatment?

decrease the workload of the heart

angiotensin receptor inhibitor (ARNI)

• used in treatment of HF

• ACE inhibitor, or ARB inhibitor (blocks RAAS)

beta blockers

used to treat HF

metroprolol, bisoprolol

reduce sympathetic stimulation

diuretics

used to treat HF

loop, potassium-sparing

vasodilators

used to treat HF

hydralazine

isosorbide dinitrate

used to treat HF

What is a cardiac glycoside?

digoxin (lanoxin)- available PO or IV

digoxin actions

• increases myocardial intracellular calcium → causing increased force of contraction (positive inotrope)

• increased Cardiac output (CO)

• decreased renin relase → decreased RAAS activation

• decreased HR ( negative chronotropic effect)

• decreased conduction velocity though the atrioventricular (AV) node

digoxin indications

• mild to moderate HF

• a fib., atrial flutter, and paroxysmal atrial tachycardia

digoxin pharmacokinetics

• therapeutic range: 0.8-2.0 ng/mL

• excreted thru kidneys

digoxin adverse effects

• vision changes (blurred vision, yellow halo around objects)

• bradycardia

• dysrhythmias (with low K+ levels)

• digoxin toxicity: when levels are too high (> 2.4ng/mL ) can be life threatening

  • early warning signs: anorexia, N/V → can progress to heart block; monitor K+ levels

_____ increases the risk of digoxin toxicity

hypokalemia

what is the reversal agent for digoxin?

digoxin immune fab (DigiBind)

what does digoxin immune fab do ?

binds to digoxin facilitating its elimination

what is ivabradine (Corlanor)?

a hyperpolarization- activated cyclic nucleotide- gated channel blocker

when is ivabradine used?

when beta blcoker therapy isnt working

must be in a normal, sinus rhythm with a HR of ≥ 70)

what is adverse effects of ivabradine?

bradycradia, atrial fibrillation, hypertension, luminous phenomena (visual changes)

What is dobutamine?

positive inotrope/sympathomimetric used in sever HF

is dobutamine a continuous infusion?

Yes: mcg/kg/min

what is a phosphodiesterase inhibitor?

milrinone (primacor)

what is milirinone used for ?

severe HF

what is the infusion for milirinone?

continous, mcg/kg/min

must be renally dosed

what are antirrhythmic agents?

drugs used to treat dysrhythmias

has 4 classes

class I antirhythmic action

action: blocks the Na+ channels in the cell membrane →phase 0 when Na+ rushes into the cell and results in depolarization

what is an example of a class I antirhythmic

Lidocaine, quinidine, procainamide

what are Class I antirhythmic agents used in?

treatments of life-threatening ventricular dysrhythmias, prevention of atrial tachycardia( flecainide), and prevention of paroxysmal atrial tachycardia (propafenone)

what should be avoided with those taking quinidine?

grapefruit → can interfere with metabolism and lead to toxic levels

lidocaine can cause____

hypotension, dysrhythmias, and CNS effects

what are class II antirhythmic

beta blockers (-olol)

what do class II antirhythmic agents do?

block beta-receptors, causing depression of phase 4 of the action potenial

slow conduction through the AV node and decrease the release of renin (from esmolol IV FORM ONLY)

what is the caution of propanolol (inderal)

caution with asthma → bronchoconstriction can occur with beta-2 receptor blockade

Monitor HR/BP

Class II antirhythmic contraindications

cardiogenic shock, sinus bradycardia, or AV Block

what is a class III antirhythmic?

amiodarone (cordarone): PO or IV

-(arones)

what are class III antirhythmic used for?

block K+ channels and prolong phase 3 of the action potential ( time of rapid repolarization as the Na+ gates closed and K+ flows out of the cell)

what is amiodarone used for ?

treatment of life-threatening ventricular tachycardia and ventricular fibrillation and in maintaining normal sinus rhythm after conversion of dysrhythmias (i.e. a fib, atrial flutter)

What are the adverse effects of amidarone?

• GI: N/V, anorexia

• hypotension (IV use)

• pulmonary toxicity

• skin discolaration (blue-grey ) with long term usage

• fatigues

• HF, cardiac arrhythmias, cardiac arrest

• hepatotoxicity

what are class IV antirhythmic?

non-dihydropyridine CBB

verapamil & diltiazem

what is the action of class IV antirhythmic?

block calcium channels in the cell membrane

what should you avoid with class IV antirhythmic?

GRAPEFRUIT

what is adenosine?

used to convert supreventrivcular tachycardia (SVT) to normal sinus rhythm ( short duration action)

Class II antirhymatic

adenosine interrupts the _____?

AV node reentry pathways and slows AV conduction time

what is the dosage of adenosine?

6mg rapid IV push (then elevate the arm) → followed by 12 mg IV q1-2 minutes x2 PRN

what kind of monitoring is necessary with adenosine?

cardiac monitoring done during administration and physician should be at the bedside

Adenosine cautions

caution in clients with asthma → can cause bronchospasm

amiodarone is the drug of choice for treatment of _______

VF or pulseless ventricular tachycardia (VT) in cardiac arrest