Favorable effects of inhaled treprostinil in severe pulmonary hypertension: results from randomized controlled pilot studies.
OBJECTIVE
This study sought to investigate the effects of inhaled treprostinil on pulmonary hemodynamics and gas exchange in severe pulmonary hypertension.


BACKGROUND
Inhaled iloprost therapy has a proven clinical efficacy in pulmonary arterial hypertension, but this therapy necessitates 6 to 9 inhalation sessions per day. Treprostinil has a longer plasma half-life and might provide favorable properties when applied by inhalation.


METHODS
Three different studies were conducted on a total of 123 patients by means of right heart catheterization: 1) a randomized crossover-design study (44 patients), 2) a dose escalation study (31 patients), and 3) a study of reduction of inhalation time while keeping the dose fixed (48 patients). The primary end point was the change in pulmonary vascular resistance (PVR).


RESULTS
The mean pulmonary arterial pressure of the enrolled patients was approximately 50 mm Hg in all studies. In study 1, both treprostinil and iloprost at an inhaled dose of 7.5 mug displayed a comparable PVR decrease, with a significantly different time course (p < 0.001), treprostinil showing a more sustained effect on PVR (p < 0.0001) and fewer systemic side effects. In study 2, effects of inhalation were observed for 3 h. A near-maximal acute PVR decrease was observed at 30 mug treprostinil. In study 3, treprostinil was inhaled at increasing concentrations with a pulsed ultrasonic nebulizer, mimicking a metered dose inhaler. A dose of 15 mug treprostinil was inhaled with 18, 9, 3, 2 pulses, or 1 pulse, each mode achieving comparable, sustained pulmonary vasodilation without significant side effects.


CONCLUSIONS
Inhaled treprostinil exerts sustained pulmonary vasodilation with excellent tolerability at relatively low doses and may be inhaled in a few breaths.
Voswinckel
Robert
R
Department of Internal Medicine, University Hospital Giessen, Giessen, Germany.
Enke
Beate
B
Reichenberger
Frank
F
Kohstall
Markus
M
Kreckel
Andree
A
Krick
Stefanie
S
Gall
Henning
H
Gessler
Tobias
T
Schmehl
Thomas
T
Ghofrani
Hossein A
HA
Schermuly
Ralph Theo
RT
Grimminger
Friedrich
F
Rubin
Lewis J
LJ
Seeger
Werner
W
Olschewski
Horst
H
D000280:Administration, Inhalation; D001794:Blood Pressure; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D011464:Epoprostenol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology*; D009330:Nebulizers and Vaporizers; D010865:Pilot Projects; D011651:Pulmonary Artery / Q000503:physiopathology; D011652:Pulmonary Circulation / Q000187:drug effects; D012720:Severity of Illness Index; D016037:Single-Blind Method; D014465:Ultrasonics; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D011464:Epoprostenol; C427248:treprostinil