phosphodiesteras inhibitor

Question 1

phosphodiesterase inhibitor:

1. name:
2. what are they?
3. action:
4. what is PDE III
5. action (continued)

Answer 1

1. amrinone, milrinone (primacor)
2. non catecholamine, nonglycoside compounds
3. competitive inhibitory action on phosphodiesterase (PDE)III
4. Inhibition of PDE III decreases hydrolysis of cAMP causing increased intracellular concentrations in the myocardium and vascular smooth muscle.(PDE III breaks down camp)
5. increases Ca++ movement into cell, potentiates the effects of catecholamines which increases cAMP causing inotropic effect with vascular and airway smooth muscle relaxation.

Question 2

phosphodiesterase inhibitors:

adverse effects:

Answer 2

1. hypotension
2. arrhythmias
3. thrombocytopenia
4. hepatic dysfunction with chronic use
5. hypokalemia
6. angina

Question 3

PDE III inhibitor:

implications:

Answer 3

1. hypotension d/t vasodilation (caution with hypovolemic patients)
2. may increase outflow obstruction in pulmonic or aortic valve disease
3. may increase ventricular response (may need to pretreat with dig if in a-fib/flutter