The Short Term Safety and Efficacy of Inhaled L-arginine in Patients With Cystic Fibrosis

Group 1 will receive the active treatment followed by the inactive treatment. The active treatment phase will consist of L-arginine 250 mg/ml dispensed in 2.2 ml vials, from which the patient will take 2ml (500mg) and dilute with 3ml of sterile water to give 5ml of a 100mg/ml solution. Dosing in the inactive treatment phase will consist of a placebo of similar osmolarity and appearance will be formulated and dosed in a similar fashion. It will consist of 2.2ml vials of 1110mmol/L hypertonic saline. Again, the patient will take 2ml and dilute with 3ml of sterile water to give a 445mmol/L solution which has similar tonicity (10%) to the L-arginine. Both treatment phases will be administered by inhalation with a PARI eFLOW device.

Group 2 will receive the inactive treatment followed by the active treatment.