Cardiotonic drugs and treatment of CHF

Question 1

Atropine sulfate: Class (5)

Answer 1

Pharmacologic: Muscarinic receptor antagonist, belladonna alkaloid
Therapeutic: antiarrhythmic, vagolytic, mydriatic

Question 2

Atropine sulfate: PD (2)

Answer 2

Blocks the effects of ACh on the SA and AV nodes -> increases conduction and HR
Decreases secretions in various glands (salivary, bronchial, sweat)

Question 3

Atropine sulfate: PK

Answer 3

Given IV, endotracheally, and topically (in the eye)

Question 4

Atropine sulfate: Toxicity (3)

Answer 4

Avoid in pts with glaucoma
Obstructive uropathy
GI obstruction, ileus, toxic megacolon

Question 5

Atropine sulfate: Special issues (5)

Answer 5

Can cause agitation, confusion (esp. in elderly), delirium, disorientation
Blurred vision
Constipation
Urine retention
Watch out esp. in older men with BPH

Question 6

Atropine sulfate: Indications, dose

Answer 6

For symptomatic bradycardia, give 0.5-1mg IV push, may repeat
Given pre-op to reduce secretions and to block cardiac vagal reflexes - 0.4mg IM 1h before anesthesia

Question 7

Dopamine: Brand name

Answer 7

Intropin

Question 8

Dopamine: Class (2)

Answer 8

Pharmacologic: adrenergic and dopaminergic receptor agonist
Therapeutic: inotropic agent, vasopressor

Question 9

Dopamine: PD

Answer 9

Stimulates DA receptors (increases renal blood flow), beta-1 (med doses) and alpha-1 (high doses) receptors at different infusion rates

Question 10

Dopamine: PK (3)

Answer 10

Can only be infused IV
Acts quickly within minutes
Half life brief (minutes), hence continuous infusion

Question 11

Dopamine: Toxicity (6)

Answer 11

Ectopy, tachycardia, angina, nausea, peripheral gangrene (excess vasoconstriction)
Extravasation

Question 12

Dopamine: Special issues (4)

Answer 12

Correct hypovolemia first
Administer through large vein
Prevent extravasation
Monitor patient closely

Question 13

Dopamine: Indications, dose

Answer 13

Shock, CHF
1 mcg/kg/min up to 30mcg/kg/min
(low = 1-2, moderate 2-10, high 10-30)

Question 14

Dobutamine: Brand name

Answer 14

Dobutrex

Question 15

Dobutamine: Class (2)

Answer 15

Adrenergic receptor agonist

Positive inotropic agent

Question 16

Dobutamine: PD (2)

Answer 16

Selectively stimulates beta-1 adrenergic receptors to increase contractility and SV -> increased CO
HR remains unchanged

Question 17

Dobutamine: PK (3)

Answer 17

Can only be infused IV
Acts quickly within minutes
Half-life brief (minutes) -> continuous infusion

Question 18

Dobutamine: Toxicity (5)

Answer 18

Ectopy, PVCs, tachycardia, hypertension, hypotension

Question 19

Dobutamine: Special issues (2)

Answer 19

Correct hypovolemia first

Monitor pt closely

Question 20

Dobutamine: Indications, dose

Answer 20

For most patients, 2.5-10mcg/kg/min

Rarely up to 40 may be needed