A comparison of the acute hemodynamic effects of inhaled nitric oxide and aerosolized iloprost in primary pulmonary hypertension. German PPH study group.
OBJECTIVE
We sought to compare the acute hemodynamic effects of inhaled nitric oxide (NO) and aerosolized iloprost in primary pulmonary hypertension (PPH).


BACKGROUND
Inhalation of the stable prostacyclin analogue iloprost has recently been described as a novel therapeutic strategy for PPH and may offer an alternative to continuous intravenous infusion of prostacyclin or inhalation of NO.


METHODS
During right heart catheterization, 35 patients with PPH sequentially inhaled 40 ppm of NO and 14 to 17 microg of iloprost, and the effects on hemodynamics and blood gases were monitored.


RESULTS
Both NO and iloprost caused significant increases in cardiac output, mixed-venous oxygen saturation and stroke volume as well as significant decreases in pulmonary artery pressure and pulmonary vascular resistance, whereas only inhaled iloprost significantly increased the arterial PO2 (p = 0.01). Compared with inhaled NO, aerosolized iloprost was more effective in reducing pulmonary artery pressure (-8.3 +/- 7.5 mm Hg vs. -4.3 +/- 8.8 mm Hg; p = 0.0001) and the pulmonary vascular resistance (-447 +/- 340 dynes x s x cm(-5) vs. -183 +/- 305 dyne x s x cm(-5); p < 0.0001). Furthermore, aerosolized iloprost caused a significantly greater increase of the cardiac output compared with NO (+0.7 +/- 0.6 liter/min vs. +0.3 +/- 0.4 liter/min; p = 0.0002) and had a more pronounced effect on the mixed-venous oxygen saturation (p = 0.003).


CONCLUSIONS
During acute drug testing, aerosolized iloprost was more potent than inhaled NO as a pulmonary vasodilator in PPH at the doses used in this study.
Hoeper
M M
MM
Department of Pulmonary Medicine, Hannover Medical School, Germany. KMHoeper@AOL.com
Olschewski
H
H
Ghofrani
H A
HA
Wilkens
H
H
Winkler
J
J
Borst
M M
MM
Niedermeyer
J
J
Fabel
H
H
Seeger
W
W
D000280:Administration, Inhalation; D000328:Adult; D000336:Aerosols; D000368:Aged; D002302:Cardiac Output / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology; D016285:Iloprost / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000008:administration & dosage* / Q000009:adverse effects; D010100:Oxygen / Q000097:blood; D011669:Pulmonary Wedge Pressure / Q000187:drug effects / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000009:adverse effects
D000336:Aerosols; D014665:Vasodilator Agents; D009569:Nitric Oxide; D016285:Iloprost; D010100:Oxygen