Cardiovascularagentsnew

1. CARDIOVASCULAR
AGENTS
for use in arrythmia:
contraction of ventricle and atrium is not synchronized.
Antiarythmia agents will block sodium channel,
potassium channel, calcium channel or
adrenergic receptor(adreneline,noradrenaline,
dopamine).
membrane stabilizing agents--aka
Class 1--- sodium channel blockers
The class I antiarrhythmic agents
interfere with the sodium channel.
Class I agents are divided into three groups
(Ia(lengthens action potential), Ib(shortens) and Ic( no
effect and increased sodium current depression)---
based upon their effect on the length of the action
potential.

2. • MOA----depresses cardiac conduction and
excitabiltity. action potential depends on the opening
of sodium ion channels, so a blockade of these
channels will slow the spread of impulse conduction
across the myocardium. mainly for tachycardia.
• Side effects:
• diarrhea, naseau, dizziness
• examples----
• lidocaine/Xylocaine
• mexiletine/Mextil
• procainamide/Pronestyl
• quinidine/Quinaglute
• tocainide/Tonocard
Vaughan Williams Classification I-IV
class 1--Na channel blocker

3. Class II--Beta blockers(olol)
used after heart attack/hypertension
moa---- beta receptors are found on muscle cells. These
drugs block adrenaline and noradrenaline from hitting
receptors. Beta-adrenergic blockers reduce
heart rate and conduction velocity through the AV node.
mainly for atrial dysrythmia.
side effects---bronchoconstriction, impotence, fatigue,
bradycardia, alopecia, depression
examples---
atenolol/Tenormin
carvedilol/Coreg
propanolol/Inderal
sotalol/Betapace
metaprolol/Lopressor

4. class III---potassium channel
blockers
moa--- K+ channels on cardiac cells affect plateau and
repolarization time. these drugs block K channel on
cardiac cells, yields more time to repolarize the cells so this
will suppress tachycardia.
side effects---possible pulmonary fibrosis, blue skin deposit,
liver damage
examples-- amiodarone, bretylium, sotalol, ibutilideamiodarone, bretylium, sotalol, ibutilide

5. class IV---calcium channel
blockers
calcium allows myosin heads to bind to actin
filaments and pull them to get a power stroke.
Cardiac muscle requires
extracellular calcium ions for contraction to occur.

6. class IV-calcium blockers
moa--Slow conduction velocity
Prolongs the refractory period
effective against supraventricular dysrhythmias
side effects----bradycardia, hypotension, constipation,
headache, dizziness, heart failure
consider----keep dilitazem from light
examples--
dilitazem/Cardizem
verapamil/Veralan

7. ACE inhibitors-(pril)
Angiotensin Converting Enzyme
mainly used in congestive heart failure----heart cannot meet
oxygen needs for the body. chambers of the heart may respond
by stretching to hold more blood to pump through the body or
by becoming stiff and thickened. heart muscle walls may
eventually weaken and become unable to pump as efficiently.
The body keeps high blood pressure by--- the protein renin from
kidneys finds protein angiotensinogen(453 amino acids)
from the liver and removes first 10 amino acids, this yields
angiotensin I(no biological activity). ACE removes another
2 amino acids to yield angiotensin II. This increases blood
pressure by increasing the amount of salt and water the body
retains. Also a vasoconstrictor.
side effects---hypotension, cough, hyperkalemia, headache,
dizziness, fatigue, nausea, and renal impairment.
examples---benazapril,enalapril, lisinopril, quinapril, ramipril,
perinopril, captopril

8. Angiotensin II antagonists
for patients who don’t tolerate ACE inhibitors.
Angiotensin II is allowed to be made but blocked at
receptor site by the drug, yields reduced blood pressure.
side effects----dizziness, headache, and/or hyperkalemia
examples-----
losartan, olmesartan, valsartan, irbesartan, eprosartan,
telmisartan, candesartan

9. Nitrates
used for angina pectoris----coronary blood flow is inadequate
for heart oxygen needs. chest pain with exertion.
moa----nitrates are converted quickly to nitric acid and yields
decreased venous return and reduced ventricular pressure,
Gives coronary vessel dilation.
side effects----orthostatic hypotension, flushing, nitroglygerin
inhalant is flammable, projection liquid from light.
examples---
isosorbide dinitrated/Isodil
isosorbide monomitrate/Imdur
nitroglygerin/Nitrostat

10. Vasodilators
moa---relax smooth muscle atrerioles, yields decreased
vascular resistance.
recommend with diuretics and sympathoplegic drugs.
side effects----headache, naseau, tachycardia, palpitations
examples----
minoxidil/Loniten
hydralazine/Apresoline
fendolapam/Corlopam

11. CNS agents
moa----reduce sympathetic outflow from vasomotor
center in the brain, yields reduced heart rate, cardiac output,
peripheral resistance.
side effects----drowsiness, fatigue, fluid retention
examples----
clonodine/Catapres
guanfacine/tenex
methyldopa/Aldomet

12. combination drugs
moa-----additive effect to lower blood pressure.
lower dosages yield less side effects
examples------
Lotensin/benazepril&HCTZ
Hyzaar/ losartan&HCTZ
Avalide/irbesartan&HCTZ