A phosphodiesterase inhibitor is any drug used in the treatment of congestive cardiac failure (CCF) that work by blocking the inactivation of cyclic AMP and act like sympathetic simulation, increasing cardiac output. There are five major subtypes of phosphodiesterase (PDE); the drugs enoximone (inhibits PDE IV) and milrinone (inhibits PDE IIIc) are most commonly used medically.
