Cardiovascular Agents 2 Flashcards
Drugs for the Treatment of Congestive Heart Failure
- VASODILATORS
- ACE INHIBITORS
- DIURETICS
- BETA STIMULATORS
- CARDIOTONIC DRUGS
Produce relaxation of the vascular smooth muscle, decreasing peripheral resistance and reducing blood pressure
They cause reflex tachycardia that occurs when BP drops
VASODILATORS
Nitrates that act to directly relax vascular muscle tone and cause decrease in blood pressure with pooling of blood in the veins.
VASODILATORS
Are employed to decrease the blood volume, which decreases the venous return and the blood pressure. The results are decreased preload and decreased afterload.
DIURETICS
These agents affect the intracellular calcium levels in the heart muscles leading to increased contractility.
CARDIOTONIC DRUGS
This will stimulate the beta receptors in the sympathetic nervous system, increasing the myocardial contraction, called positive inotropic effect.
BETA STIMULATORS
These are agents extracted from the foxglove plant. These are available in oral and parenteral preparations
CARDIAC GLYCOSIDES
Agents that block the conversion of angiotensin I to angiotensin II. The result is blockage of the vasoconstriction and decreased blood volume. The afterload will be decreased.
ACE INHIBITORS
Example of Cardiotonic Drugs
- CARDIAC GLYCOSIDE
- PHOSPHODIESTERASE INHIBITORS
The myocardium will contract forcefully that results to increased cardiac output and increased blood flow. This effect is called ______
POSITIVE INOTROPIC EFFECT
This effect causes the heart rate to slow down due to the decreased rate of cellular repolarization. May also cause bradycardia.
NEGATIVE CHRONOTROPIC EFFECT
Examples of cardiac glycosides
- Digoxin
- Digitoxin
- Ouabain
Used to treat severe hypertension
VASODILATORS
Example of vasodilators
- Hydralazine
- Minoxidil
- Diazoxide
- Sodium Nitroprusside
It acts directly on vascular smooth muscle to cause muscle relaxation, leading to vasodilation and drop in BP
VASODILATORS
One of the adverse effect of vasodilators which may occur with nitroprusside
CYANIDE TOXICITY
They INCREASE levels of calcium inside the cell by inhibiting the Sodium-Potassium pump
CARDIAC GLYCOSIDES
Digitalis is also called ____
DIGOXIN
T / F:
Cardiac glycosides cause more calcium to accumulate inside the cell during depolarization
TRUE
Clinical uses of cardiac glycosides
- Congestive heart failure
- Dysrhythmias
Cardiac glycosides are not given to patients with?
ELECTROLYTE IMBALANCE:
- Hypokalemia
- Hypomagnesemia
- Hypercalcemia
Antidote for digitalis toxicity & cardiotoxicity:
Digitalis toxicity:
- DIGOXIN IMMUNE (Ovine, Digibind)
Cardiotoxicity:
- Phenytoin
- Lidocaine
Drug-Drug interactions of cardiac glycosides
Can INCREASE effects of digitalis: Verapamil, Amniodarone, Quinidine, quinine, erythromycin, tetracyclines
Can INCREASE risk of toxicity & arrhythmias: Potassium-losing diuretics (Furosemide)
Can cause IMPAIRED absorption of digitalis: cholestyramine, charcoal, colestipol
What to monitor before administering digitalis?
APICAL PULSE for 1 minute
Withhold the administration of digitalis if apical pulse is?
Adults:
- Less than 60
- More than 110
Infants:
- Less than 90
Therapeutic level of digitalis in the blood
0.5 - 2.0 nanograms/mL
