The invention relates to therapeutic antisense oligonucleotides directed against genes coding for phosphodiesterase (PDEs) and the use of these in combination. These antisense oligonucleotides may be used as analytical tools and/or as therapeutic agents in the treatment of disease associated with reduced cellular cAMP in a patient, such as inflammatory diseases of the respiratory tract including, for example, asthma, chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome, bronchitis, chronic bronchitis, silicosis, pulmonary fibrosis, lung allograft rejection, allergic rhinitis and chronic sinusitis as well as other conditions in which an increase in cyclic AMP or a decrease in PDE levels is beneficial.