Phosphodiesterase Inhibitors

drugs

amrinone, milrinone

action

block the enzyme phosphodiesterase; this blocking effect lead to an increase in myocardial cell CAMP, which increases calcium levels in the cell. Increased cellular calcium causes a stronger contraction and prolongs the effects of sympathetic stimulation which leads to vasodilation, increased oxygen consumption and arrhythmias

indication

short-term treatment for CHF

contraindications

• Allergy to bisulfites.

• Severe aortic or pulmonic valvular disease

• Acute MI

• Fluid volume deficit

• Ventricular arrhythmias

adverse reactions

hypotension and chest pain, nausea, vomiting, anorexia and abdominal pain, thrombocytopenia

Nursing Responsibilities

• Protect the drug from light

• Monitor pulse and blood pressure periodically during administration

• Monitor input and output and record daily weights

• Monitor platelet counts prior to and regularly during therapy.

• Arrhythmias are disruptions in the normal rate or rhythm of the heart

• Electrolyte disturbances, decreases in the oxygen delivered to the cells, structural damage in the conduction pathway, drug effects, acidosis or the accumulation of waste products can trigger arrhythmias