Any process that stops or reduces the rate of cyclic nucleotide phosphodiesterase activity, the catalysis of the reaction: nucleotide 3',5'-cyclic phosphate + H2O = nucleotide 5'-phosphate.
Synonyms:
exact_synonym:
3',5' cyclic nucleotide phosphodiesterase inhibitor; down regulation of cyclic nucleotide phosphodiesterase activity; downregulation of cyclic nucleotide phosphodiesterase activity; negative regulation of 3',5' cyclic nucleotide phosphodiesterase activity
narrow_synonym:
3',5'-cyclic-AMP phosphodiesterase inhibitor; cAMP phosphodiesterase inhibitor; inhibition of cyclic nucleotide phosphodiesterase activity; negative regulation of 3',5'-cyclic-AMP phosphodiesterase activity; negative regulation of cAMP phosphodiesterase activity; negative regulation of cGMP phosphodiesterase activity