SELECT *
  FROM RDB$PROCEDURE_PARAMETERS


  SELECT B.RDB$PARAMETER_NAME NOME,

         CASE RDB$PARAMETER_TYPE
           WHEN 0 THEN 'INPUT'
           WHEN 1 THEN 'OUTPUT' END TIPO
  FROM   RDB$PROCEDURES A INNER JOIN RDB$PROCEDURE_PARAMETERS B ON
(A.RDB$PROCEDURE_NAME = B.RDB$PROCEDURE_NAME)
  WHERE  A.RDB$PROCEDURE_NAME = :NOMEDAPROCEDURE


  SELECT A.*
  FROM RDB$PROCEDURES A