cardiac drugs Flashcards
which diuretics do we not use for cardio patients
carbonic anhydrase (dorzolamide) and osmotic diuretics (oliguric renal failure patients)
treatment of choice in edema of cardiopulmonary, hepatic and renal origin
furosemide, loop diuretic
things to remember when you put a patient on furosemide
watch for dehydration and tolerance to the drug. increase dose=increase effect
what is the main difference between thiazide and loops (furosemide)
thiazide does can cause hypercalcemia and it can decrease renal blood flow. furosemide does the opposite
if we have a patient that is hypercalcemic and/or azotemic, what drugs do we avoid?
thiazide diuretics and digoxin ( +inotrope by increasing calcium)
competitive antagonist with aldosterone, this antagonist rship decreases cardiac fibrosis and reduces ion reuptake.
what drug?
spironolactone (potassium sparing diuretic)
what does NSAIDS do to our cardiac treatment
decreases the effects of diuretics and vasodilators, decreases furosemide getting to the loop of henle.
what do ACEi do? who are they for
decrease congestion by vasodilation and decrease ion reuptake
benazepril elanapril
dogs and cats
what is the preferred vasodilators for our renal failure patients
benazapril: hepatic and renal secretion
Treatment of choice in cats with systemic hypertension
amlodipine
drug that causes pulmonary vasodilation and used for pulmonary hypertension in combo with other drugs
sildenafil (phosphodiesterase inhibitor)
what is an effect of ACEi
azotemia
in hospital drug we reach for when MAP >220
hydralazine. risk of severe hypotension. ER drug
dog treatment when furosemide cant be used
thiazide diuretic
when do we reach for vasodilators
systemic hypertension or CHF adjunctive therapy especially in DMVD
when do we reach for antiarrhythmics
when there is an arrhythmia that is incompatible with life or it could lead to life threatening arrhythmias
emergency treatment for VTach
lidocaine IV or procainamide
what toxicity signs are we looking for when giving lidocaine IV
neuro signs, seizures. cats are extra sensitive
what do we do if its been an hour in VTach, and no drugs are working
sedate dog and shock to try and reset their heart. its painful and dangerous
ecg shows tachy with narrow QRS and regular rhythm. what drug do we reach for
procainamide, decreases slope and slows action potential
what are our class two antiarrhythmics
beta blockers, inhibit sympathetic influence
what antiarrhythmics can you never use together
potassium channel blockers and drugs that decrease potassium.
what myocytes use potassium to repolarize
ventricular cells. so K channel blockers work in vent
what cells use calcium to repolarize
atria and AV node. can only use on SVT
what is our acute management of afib
usually doesnt require ER drugs. can start oral digoxin + diltiazem.
chronic treatment for Vtach
mexiletine and sotalol
how should we think about mexiletine
oral form of lidocaine
acute treatment of SVT
vagal maneuvers- retropulsion and carotid massage. increases vagal tone to slow AV node
then diltiazem our C IV drug to slow depolarization
chronic treatment of SVT
diltiazem and atenolol
what is our goal with afib dogs? drug?
slow the rate of the fibs so that it is compatible with life. do not try and cure the fibs.
diltiazem and digoxin
digoxins slows av conduction by increasing PS tone
what does digoxin do to heartrate
negative chronotrope by slowing av conduction by increasing PS tone
what are the rules about digoxin use
- sample 8 days after you start the drug, 8hrs after dose was given, and serum levels need to be <0.8ng/ml
atrial fib in a horse
quinidine, or internal cardioversion if you caught it early and there is not heart failure.
what are our class II drugs
atenolol
atenolol, BBlocker, can be used for
chronic management of VTach or afib
due to it blocking sym effects
class III drugs and type
potassium channel blockers,
sotalol and amiodarone
why can we use C III drugs for atrial and ventricular arrhythmias
all myocytes use K+ to repolarize
why would I reach for dobutamine
+ inotrope (inc contractility)
acute heart failure with systolic dysfunction
dog comes in with acute heart failure due to DCM what drugs do i give
dobutamine and pimobendan (increase contractility)
why do we use dobutamine and not dopamine is heart failure treatment
dopamine is a vasoconstrictor which causes the heart to have to work harder. not ideal
treatment of acute onset heartfailure- respiratory signs
furosemide. give before rads even if unsure its heartfailure.
why do we like pimobendan for heart failure
it increases contractility while also vasodilating
who do we give pimobendan to
MMVD, DCM, any decrease in contractility HF
acute positive inotrope
dobutamine
when do we reach for spironalactone
when we have ACEi on board and feel like the chymase pathway is being used
stage C MMVD
DCM?
vasodilate and decrease blood volume
MMVD, DCM, stage C MMVD
ACEi . BID
how do we give thiazides
EOD in conjunction with furosemide to get exponential effects compared to furosemide alone
chronic heart failure drug combos
furosemide diuretic
pimobendan inc cont
ACEi: decrease BP, vasod
Spironalactone: helps ACEi
+- thiazide, +- digoxin if afib
+- antiarrhythmic
diuretics are contraindicated in what patients
pericardial effusion patients, their barely moving blood as it is and we dont need to decrease blood volume.
decrease in preload
