Drugs

Question 1

By binding to and inhibiting this transporter, digitalis causes the intracellular [Na+] to rise. An increase in intracellular sodium content reduces Ca++ extrusion from the cell via the Na+/Ca++ exchanger. Consequently, more Ca++ is pumped into the sarcoplasmic reticulum, and when subsequent action potentials excite the cell, a greater-than-normal amount of Ca++ is released to the myofilaments, thereby enhancing the force of contraction.

Answer 1

Digixon

Question 2

The major therapeutic electrical effect of digoxin occurs at the

Answer 2

AV node.

Question 3

Digixon modifies autonomic nervous system output by enhancing vagal tone and reducing ___ activity. As a result, digitalis decreases the frequency of transmission of atrial impulses through the AV node.

Answer 3

sympathetic

Question 4

It is not beneficial in forms of heart failure associated with normal ven- tricular contractility (i.e., heart failure with preserved ejection fraction).

Answer 4

Digixon

Question 5

Many factors contribute to digitalis intoxication, the most common of which is ___, often caused by concurrent administration of diuretics. ____ exacerbates digitalis toxicity because it further inhibits Na+K+-ATPase.

Answer 5

hypokalemia

Question 6

At low dosages, less than 2 μg/kg/min, dopamine interacts primarily with dopaminergic receptors distributed in the renal and mesenteric vascular beds. Stimulation of these receptors causes local vasodilation and increases renal blood flow and glomerular filtration, facilitating diuresis

Answer 6

Dopamine

Question 7

Medium dosages of dopamine, 2 to 10 μg/kg/min, increase inotropy directly by stimulating cardiac β1-receptors

Answer 7

These actions increase heart rate, cardiac contractility, and stroke volume, all of which augment CO.

Question 8

High-dose dopamine is indicated in ____. However, these doses are inappropriate in most patients with cardiac failure because the peripheral vasoconstriction increases the resistance against which the heart contracts (i.e., higher afterload), which could impair left ventricular output.

Answer 8

hypotensive states such as shock

Question 9

____ is a synthetic analog of dopamine that stimulates β1-, β2-, and α-receptors. It increases cardiac contractility by virtue of the β1 effect but does not increase peripheral resistance because of the balance between α-mediated vasoconstriction and β2-mediated vaso- dilation

Answer 9

Dobutamine

Question 10

Like dopamine, it is useful for short-term therapy (less than 1 week), after which time it loses its efficacy, presumably because of down-regulation of adrenergic receptors. The major adverse effect is the provocation of tachyarrhythmias

Answer 10

Dobutamine

Question 11

Unlike norepinephrine and epinephrine, it is a “pure” β-agonist, having activity almost exclusively at β1- and β2-receptors, with almost no α-receptor effect. In the heart, ___ has positive inotropic and chronotropic effects, thereby increasing CO.

Answer 11

isoproterenol

Question 12

____ is sometimes used in emergency circumstances to increase the heart rate in patients with bradycardia or heart block

Answer 12

Isoproterenol

Question 13

____ should be avoided in patients with myocardial ischemia, in whom the increased heart rate and ino- tropic stimulation would further increase myocardial oxygen consumption.

Answer 13

Isoproterenol

Question 14

___ displays the electrophysiologic effects inherent to class IA agents but also has anticholinergic properties that may augment conduction at the AV node, thus antagonizing its direct suppressant effect.

Answer 14

Quinidine

prolongs QT, widens QRS

Question 15

Cinchonism refers to CNS toxicity by ____ manifested by tinnitus, confusion, hearing loss, and visual disturbances. Quinidine can cause excessive prolongation of the QT interval, which may lead to torsades de pointes.

Answer 15

quinidine

Question 16

____ has similar electrophysiologic effects as quinidine, though it does not prolong the action potential (and therefore QT interval) as much.

Answer 16

Procainamide

Question 17

____ has mild ganglionic blocking effects that may cause peripheral vasodilation and a negative cardiac inotropic effect.

Answer 17

Procainamide

Question 18

______’s electrophysiologic and antiarrhythmic effects are similar to those of quini- dine, but it has a greater anticholinergic effect. More so than quinidine or procainamide, _____ also has a pronounced negative inotropic effect and must be used with caution in patients with left ventricular systolic dysfunction.

Answer 18

Disopyramide

Question 19

Digoxin is not beneficial in forms of heart failure associated with normal ventricular contractility (i.e., heart failure with preserved ejection fraction).

Although no longer a mainstay of therapy in heart failure, digitalis is sometimes useful in treating patients with heart failure complicated by

Answer 19

atrial fibrillation

Question 20

The treatment of digitalis-induced tachyarrhythmias may include administration of potassium (if hypokalemia is present), intravenous ____ for bradyarrhythmias, or lidocaine (discussed later in the chapter) for ventricular ectopy

Answer 20

atropine

Question 21

Milrinone, a nondigitalis, noncatecholamine agent, exerts its positive inotropic actions by inhibiting phosphodiesterase type 3 in cardiac myocytes.

Milrinone is sometimes used in the treatment of acute heart failure when there has been insufficient improvement with conventional vasodilators, inotropic agents, and diuretics. It has the potential for serious adverse effects, including provocation of ventricular arrhythmias, and chronic milrinone therapy is associated with ___ mortality. Its use is therefore lim- ited to hospitalized patients for short-term therapy.

Answer 21

increased

Question 22

_____ has proved useful for maintaining blood pressure in patients with vasodilatory shock, as may occur in sepsis. It may also be beneficial during advanced life support for cardiac arrest because it increases coronary perfusion pres- sure, augments blood flow to vital organs, and improves the likelihood of successful resuscitation in patients with ventricular fibrillation.

Answer 22

Vasopressin

Question 23

____ is an intravenous direct thrombin inhibitor, which is equivalent to UFH plus a GP IIb/IIIa inhibitor in preventing adverse ischemic outcomes, with less associated bleeding, in patients with UA or NSTEMI treated with an early invasive strategy.

Answer 23

Bivalirudin

Question 24

In clinical trials in patients with UA or NSTEMI, the LMWH ____ has demonstrated reduced death and ischemic event rates compared with UFH.

Answer 24

enoxaparin

Question 25

____ is a subcutaneously administered agent that is a very specific factor Xa inhibitor. Its effect is similar to the LMWH enoxaparin at reducing cardiac adverse events but with fewer bleeding complications.

Answer 25

Fondaparinux

Question 26

DTIs do not cause thrombocytopenia and are used to maintain anticoagulation and prevent thrombo- sis in patients with HIT. ____ is approved for use as an anticoagulant in patients with unstable angina undergoing percutaneous coronary intervention.

Answer 26

Bivalirudin

Question 27

The most common side effects of____ are related to the CNS and include confusion, paresthesias, dizziness, and seizures. These effects are dosage related and can be prevented by monitoring serum levels of the drug.

Answer 27

lidocaine

Question 28

In some circumstances, even more powerful antiplatelet agents are utilized in ACSs. The glycoprotein (GP) IIb/IIIa receptor antagonists (which include the monoclonal antibody ____) are potent antiplatelet agents that block the final common pathway of platelet aggregation

Answer 28

abciximab

Question 29

In a percutaneous coronary intervention (PCI) capable hospital, the goal is to get the patient to PCI within 90 minutes. Once this is possible, it is recommended to administer a ____. Some research has shown a 60% decrease in death and further MI with this class of medications.

Answer 29

GP IIb/IIIa inihibitor, such as abciximab,