Pharm Exam 2 Cardiac-Diana

Question 1

Phosohodiasterase inhibitors

Answer 1

1. Inhibit the breakdown of cAMP by PDE3 increasing calcium from the SR therefore increasing the force of contraction of actin-myosin.
2. Vasodilation action of smooth muscle happens by inhibiting PDE3 increasing cAMP activating LMCK inhibiting smooth muscle contraction and causing relaxation.

Question 2

Digoxin

Answer 2

Increases the cell’s calcium by inhibiting action of Na+/K+ ATPase on the cell membrane of cardiac myocytes increasing intracellular Na+ decreasing Na+ and Ca+ exchange that leads to indirect increase of intracellular Ca+ activating acting and myosin

Question 3

Levosimedan

Answer 3

Calcium sensitizer works primarily during systole by modulating the action of calcium with actin and myosin prolonging the action of calcium during contraction.

Question 4

B1 receptors

Answer 4

1. platelets-causes platelet aggregation

2. heart-causes inotropic and chronotropic effect

Question 5

B2 receptors

After increasing cAMP it increases Na+K+ ATPase activity and hyper-polarization

Answer 5

1. bronchi, vascular smooth muscle, uterus (and heart)

Question 6

D1 receptors

Answer 6

1. Central-modulates extrapyramidal activity

2. Peripherally-vasodilation of renal and mesenteric vasculature

Question 7

D2 receptors

Answer 7

1. central-reduced pituitary hormone output

2. peripherally-inhibit further noradrenaline release

Question 8

Metabolism of vasopressors

Answer 8

1. Catecholamines (Ex: epi, norepi, dopamine, dobutamine,iso, etc) are inactivated by catechol-O- methyltransferase (COMT) and Monoamine oxidase (MAO) (not dobutamine).
2. ~25 % of Dopamine is converted to norepi in adrenergic nerve terminals with reuptake of norepi in these terminals.
3. Phenylephrine is metabolized by MAO
4. Vasopressin metabolized by vasopressinases in liver and kidney
5. Ephedrine and Milrinone are excreted in the urine
6. Levosimendan metabolizes into active compounds, and eliminated up to a week after drug is stopped

Question 9

alpha 1 receptor

Answer 9

Located in vascular smooth muscle
Stimulation produces vasoconstriction in capacitance & resistance vessels
Produces relaxation in intestinal smooth muscle

Question 10

alpha 2 receptor

Answer 10

stimulation leads to inhibition of NE release, platelet aggregation and inhibition of insulin release

Question 11

Dopamine

Answer 11

1. Synthesized in the kidney and has both diuretic and natriuretic effects and in the CNS is a neurotransmitter
2. Stimulates alpha, beta 1 and dopamine 1 primarily in mesenteric and renal vasculature.

Question 12

Dopamine

Answer 12

increases contractility, renal blood flow, glomerular filtration rate, sodium excretion, and urine output
Drug of choice for septic shock esp. with systolic dysfunction

Question 13

Dopamine dosage

Answer 13

a) 3mcg/kg/min
increases renal blood flow, inhibits aldosterone, which increase urine output
b) 3-10mcg/kg/min 
act on β receptors
increasing myocardial contractility 
used as inotrope evoking release of NE 
can cause CHF if depleted NE stores
c) 10-20 mcg/kg/min 
α and β adrenergic effects
ventilator support may be needed because if the effects on the carotid bodies

Question 14

Rationale for holding ACE inhibitors 24 hours before surgery

Answer 14

1. Anesthetics blunt SNS response
2. ACE inhibitors block RAAS
   Therefore, if patient develops profound hypotension you can only use vasopressin or methylene blue

Question 15

methylene blue

Answer 15

Competes with NO for the binding to guanylyl cyclase inhibiting vasodilation