Cumulative RX qbank notes

Question 1

Hydralazine

Answer 1

Hydralazine is a potent arteriole vasodilator that is first-line treatment for hypertension in pregnancy. It produces significant tachycardia, so it should be administered with a β-blocker such as labetalol to prevent this reflex response. Hydralazine can be used to quickly lower an elevated blood pressure in the peripartum setting as its effect is rapid.

Question 2

Methyldopa

Answer 2

Centrally acting alpha agonist that is a well established antihypertensive during pregnancy. Can cause bradycardia

Question 3

What happens in acute respiratory acidosis?

Answer 3

PaCO2 is elevated and an acidemia (pH

Question 4

rate of ventilation is controlled primarily by?

Answer 4

Central chemoreceptors sensitive to pH. CO2 can diffuse across blood-brain barrier into cerebrospinal fluid where it combines with water to become bicarbonate and protons. This INC in acidity lowers the pH and results in hyperventilation.

Question 5

Heroin toxicity

Answer 5

Body loses ability to appropriately ventilate and acute respiratory acidosis results.

Question 6

Norepinephrine

Answer 6

INC venous return to heart, leading to INC in stroke volume. Since heart no longer needs to beat as fast to maintain sufficient CO, there is a reflex DEC in heart rate. Known as reflex bradycardia effect of norepinephrine.

Since norepinephrine acts with greater affinity for alpha receptors than beta receptors, this reflex bradycardia in response to alpha1 mediated vasoconstriction outweights any beta1 mediated INC in heart rate, resulting in a NET DEC in heart rate.

Question 7

Adrenergic receptors are what type of class receptors?

Answer 7

G-protein-coupled receptors that are targets of catecholamines such as norepinephrine and epinephrine which are located on smooth muscles throughout the body.

Question 8

Alpha1 receptors

Answer 8

responsible for vasoconstriction of arteries causing INC BP

Question 9

Beta receptors (particularly beta1)

Answer 9

responsible for INC contractile force and heart rate

Question 10

Labetalol

Answer 10

nonselective blocker of both alpha and beta adrenergic receptors. It is useful for counteracting norepinephrine’s vasoconstrictive effects on the vasculature and its inotropic/chronotropic effects on the heart

Question 11

Isoproterenol

Answer 11

nonselective agonist at both beta1 and beta2 receptors. It would enhance the cardiac effects of norepinephrine via its actions on bet1 receptors, while its action on beta2 receptors (vasodilation) would antagonize the vasoconstrictive properties that norepinephrine would exert via alpha1 receptors

Question 12

Esmolol

Answer 12

short acting beta1 selective antagonist, and would only control cardiac effects of norepinephrine

Question 13

Doxazosin

Answer 13

Selective alpha 1 antagonist that is used to treat HTN and urinary retention in the setting of benign prostatic hyperplasia. It would be effective at blocking norepinephrine’s effect on the vasculature, but would not antagonize its action on the heart