HTN Drugs

Question 1

ACE-I MOA

Answer 1

Block AII production by preventing ACE from catalyzing AI to AII

Leads to vasodilation and decrease in Na reabsorption

Question 2

ARB MOA

Answer 2

Directly block AII receptor without blocking breakdown of bradykinin

Question 3

Cause of cough from ACE-I

Answer 3

ACE usually breaks down bradykinin. ACE-I block ACE, preventing the breakdown of bradykinin, causing it’s buildup and leading to coughing

Question 4

Renal route to increase BP

Answer 4

Catecholamine release—> renin release —> Angiotensinogen to AI —> ACE converts AI to AII —> AII increase BP via vasoconstriction and retention of Na/H2O

Aldosterone also released increasing NA retention

Renin release is a B1 action

Question 5

Direct renin inhibitor MOA

Answer 5

Prevents renin release from kidneys which prevents angiotensinogen from becoming AI

Question 6

Fenoldopam

Answer 6

Class: Dopamine-1 receptor antagonist

Dose: 0.1-1.6 mcg/kg/min

Onset: 4-5 min

Duration: <10 min

Question 7

Labetalol

Answer 7

Alpha and beta adrenergic blocker

Dose: 5-10 mg increments

Onset: 1-3 mins or less

Duration: 3-6 hrs

Question 8

Nicardipine

Answer 8

Calcium channel blocker

Dose: 5 mg/hr increased in 2.5 increments up to 15

Onset: 1-5 min

Duration 3-6 hrs

Question 9

Clevidipine

Answer 9

calcium channel blocker

Dose: infusion 1-2 mg/hr

Onset: 2-4 min

Duration: 5-15 min

Question 10

Nitroglycerin

Answer 10

Venous vasodilator

Dose: infusion 5-100 mcg/min, 5 mcg/kg/min increase q5min

Onset: 2-5 min

Duration: 5-10 min

Tolerance and reflex tachycardia may develop

Question 11

Sodium nitroprusside

Answer 11

Arterial and venous vasodilator

Dose: pump 0.3-10 mcg/kg/min, Do not increase more than 2 mcg/min

Onset: seconds

Duration 3-5 min

Cyanide toxicity

Question 12

Sodium Nitroprusside Metabolism

Answer 12

Direct vasodilator/releases NO

NO goes into vessel wall/vasodilates—> 5 cyanide molecules surround NO —> cyanohg—> cyanides go to blood —> thiosulfate combines with cyanide to make thicyanate —> eliminate in the kidneys

Question 13

Cyanide toxicity

Answer 13

cytochrome oxidase burns O2 via cellular respiration, cyanide can block tissue respiration and cause hypoxia. Oxygen is not getting to tissues so venous blood looks as red as arterial blood

Question 14

S/S of Cyanide toxicity

Answer 14

CNS dysfunction: mental status change, seizure, coma

CV instability: tachyphylaxis, hypertension

ECG changes

Metabolic acidosis

Question 15

Treatment of Cyanide toxicity

Answer 15

Stop infusion
100& O2
Mechanical ventilation as needed to prevent acidosis
Correct metabolic acidosis with nabicarb
3% Na nitrate
Na thiosulfate
Consider B12

Question 16

Esmolol

Answer 16

Beta Blocker

Dose: 0.5-1.0 mg/kg then 50-300 mcg/kg/min infusion

Onset: 1-2 min

Duration: 10-30 min

Broken down by RBC esterases making it shorter acting

Question 17

Phentolamine

Answer 17

Dose: 1-5 mg

Onset: 1-2 min

Duration: 3-5 min

Question 18

ACE-I Examples

Answer 18

-pril

Question 19

ARB examples

Answer 19

-sartan

Question 20

Direct Renin Inhibitor Example

Answer 20

Aliskiren

Question 21

CCB

Answer 21

-Dipine + Verapamil and Diltiazem

Question 22

BB with Alpha Blocking Activity

Answer 22

Carvedilol and Labetolol

Also cause vasodilation along with BB effects

Question 23

Alpha Adrenergic Blockers

Answer 23

Vasodilate, mainly used on pots with BPH

Minipress, Doxazosin

Question 24

Central Alpha Agonists

Answer 24

Clonidine

VERY potent, reserved for most brittle HTN—>pt take prior to surgery

Withdrawal and a lot of side effects

Question 25

Direct Vasodilators

Answer 25

Hydralazine:
Direct arterial dilator —> reduce afterload

Nitroglycerin: venous dilator—> reduce preload

Nitroprusside: venous and arterial dilator —>reduce preload and afterload

Question 26

BB SE

Answer 26

Also block B2 receptors causing bronchoconstriction, hypoglycemia, and vasoconstriction

Question 27

Hydralazine

Answer 27

Give if pt HTN and bradycardic. Pure vasodilator so wont cause more bradycardia, instead cause reflex tachycardia

Wait out and do not stack doses