The present invention relates to novel methods, compositions and kits useful for the treatment of pulmonary diseases such as pulmonary arterial hypertension. In particular, aerosolisable compositions of iloprost are provided which are for use in inhalation therapy. Their administration is by bolus inhalation, which is patient-friendly, effective, and well tolerated. Bolus inhalation may, for example, be achieved using an efficient nebuliser based on the vibrating mesh technology.
