Vasodilators

Question 1

Minoxidil

Answer 1

Enhances K+ efflux from cells causing severe hypotension due to increased hyperpolarization; will cause compensatory increase in HR and CO

ADRs: Fluid Retention (use diuretic), Tachycardia (Use B-blocker), and hypertrichosis
***THIS DRUG IS ALSO KNOWN AS ROGAINE

Question 2

Nitroprusside

Answer 2

• Works by activating guanylyl cyclase =» increased cGMP
  
  • **arteriodilation=venousdilation
• Leads to decreased TPR (arterio) and decreased CO (venous) but a compensatory increasd in HR

TIs: ***HTN EMERGENCY, MI, CHF

ADRs: Cyanide toxicity (if not enough thiosulfate) which looks like someone took a cyanide capsule causing convulsions and respiratory arrest
-If pt. has thiosulfate, Rhodenase converts CN- and just causes thiocyanate toxicity which presents as delirium

Question 3

Nitroglycerin

Answer 3

Guanylyl cyclase activator causing increased cGMP
***Venodilation»>Arteriodilation

-Will only cause decreased TPR at high doses due to this; undergoes first-pass elimination so given sublingual or transdermal

TIs: Angina, CHF, acute MI

ADRs: Angina (excess vasodilation), tolerance

Question 4

Nitric Oxide

Answer 4

Vasodilator by increasing cGMP; only indication is for respiratory failure in neonates w/ pulmonary HTN

ADRs: Pulmonary edema, Sudden hypoxemia after withdrawl

Question 5

Hydralazine

Answer 5

Oral drug that causes arteriodilation (decreased TRP) and compensatory increased HR

-Used for CHF and HTN

ADRs: (+) ANA pts. =»Lupus-like syndrome
Fluid retention

Question 6

Fenoldopam

Answer 6

D1 agonist used for HTN emergencies sometimes

Question 7

PDE inhibitors

Answer 7

Sildenafil, Tadalafil

-Potentiate the effect of NO cause vasodilation in the corpus cavernosum (sildenafil givin boners) and smooth muscle relaxation in the lower urinary tract (TADA, your wiener works.)

ADRs: Hypotension, avoid concurrent a-blockers

Question 8

ACEIs

Answer 8

Enalapril (prodrug), Lisinopril

-Caused decreased conversion of Angiotensin I to Angiotensin II
=»Decreased aldosterone (decreased Na+ and H2O reabsorption and has direct vasodilation effect; also cause decreased inactivation of bradykinins further increasing vasodilation

TIs: HTN, post-MI, CHF, Diabetic neuropathy

ADRs: COUGH, fetopathic potential (no preggers), hyperkalemia

Question 9

Losartan, Valsartan

Answer 9

ARBs

-Competitive antagonist at ATII receptors; have same effects as ACEIs but do not decrease bradykinin deactivation

TIs: Diabetic neuropathy, post-MI, CHF, HTN

ADRs: Fetopathic potential, hyperkalemia

Question 10

Aliskrien

Answer 10

Renin inhibitor leading to decreased ATI conversion

• Used for HTN
• Same ADRs as ARBs

Question 11

Ca2+ Channel Blockers

Answer 11

Amlodipine (Dihydropyridine) and Verapamil (Not a dihydro)

Causes decreased smooth muscle contraction of peripheral vessels causing decreased TPR; amlodipine has the strongest effect on this
-Verapamil will block L-type calcium channels causing a decreased inotropy of the heart and decreased conduction in the SA/AV nodes

TIs: Angina, supraventricular tachyarrhythmia (verapamil), HTN
-Verapamil also causes decrease in CO

ADRs: Amlodipine =»Hypotensions, edema, and headaches
-Verapamil also causes these (less severe) alongside CHF, AV block

⭐️Avoid use alongside any hepatic failure or concurrent drugs that decrease heart function