The labelled S-isomer of Mesopram (M225670),((S)-Mesopram-d7) Mesopram is an orally active phosphodiesterase (PDE) 4 inhibitor. Mesopram decreases the synthesis of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN -γ). Mesopram is used in compositions for the treatment or prevention of respiratory inflammation.