Vasoldilators

Question 1

vasodilators

Answer 1

1. drugs that dilate arterioles => ↓ SVR => ↓ cardiac workload (after load) => ↓ BP
2. drugs that dilate veins => ↓ venous return, ventricular filling => ↓ contractility => ↓ cardiac workload => ↓ BP

Question 2

vasodilators - indications

Answer 2

HTN
hypertensive crisis
angina
HF
Myocardial infarction (MI)

Question 3

which classes of drugs are vasodilators?

Answer 3

ACEI - arterioles
ARBs - arterioles
CCBs - arterioles
Nitrates - veins
Sympatholytics
  - Alpha 1 blockers - arterioles and veins
  - Alpha 2 agonists
Others - Nitroprusside (Nipride) - arterioles and veins

Question 4

what is a hypertensive crisis?

Answer 4

1. medical emergency (diastolic BP > 120)
2. usually asymptomatic until then
3. may cause organ damage
   
   • papilledema (optic disc swelling), stroke, intracranial bleeding, MI
   • BP must be lowered rapidly if organ damage is evident
4. If no evidence of organ damage - lower BP gradually == rapid drop can cause cerebral ischemia

Question 5

Drug of choice for hypertensive crisis?

Answer 5

nitroprosside (Nipride) - when BP needs to be lowered rapidly

Question 6

nitroprosside (Nipride) - how does it work? and for what?

Answer 6

hypertensive crisis
- potent vasodilator = both veins and arterioles  = releases nitric oxide
 - produces cyanide groups
Administered through arteriole IV
Half life = 10 min.

Question 7

nitroprosside (Nipride) - side effects

Answer 7

severe hypotension
cyanide poisoning

• Monitor cyanide level = avoid prolonged, rapid infusion