Effects of acetazolamide on central blood pressure, peripheral blood pressure, and arterial distensibility at acute high altitude exposure.
OBJECTIVE
We assessed the haemodynamic changes induced by exposure to high altitude hypoxia and the effects on them of acetazolamide, a drug prescribed to prevent and treat mountain sickness.


RESULTS
In 42 subjects (21 males, age 36.8 ± 8.9 years) randomized to double blind acetazolamide 250 mg b.i.d. or placebo, pulse wave velocity and pulse wave parameters were assessed (PulsePen) at baseline; after 2-day treatment at sea level; within 6 h and on 3rd day of exposure to high altitude. Exposure to high altitude significantly increased diastolic (P < 0.005) and mean blood pressure (BP) (P < 0.05, after prolonged exposure) in placebo but not in the acetazolamide group. Therefore, subjects on acetazolamide showed significantly lower values of diastolic (P < 0.005) and mean BP (P < 0.05) at altitude. Furthermore, they also showed significantly lower values of systolic BP (P < 0.05). Pulse wave velocity did not change at high altitude, while the augmentation index, normalized for a theoretical heart rate of 75 b.p.m., significantly increased (P < 0.05) under placebo, but not under acetazolamide. In a multivariate model, unadjusted augmentation index at high altitude was not affected by BP changes, while significant determinants were heart rate and gender.


CONCLUSIONS
Acute exposure to high altitude induced a rise in brachial BP and changes in pulse waveform-derived parameters, independent from changes in mean BP and partly counteracted by treatment with acetazolamide. The impact of acetazolamide on the haemodynamic alterations induced by hypobaric hypoxia may be considered among the beneficial effects of this drug in subjects prone to mountain sickness.


BACKGROUND
EudraCT Number: 2010-019986-27.
Department of Cardiology, S. Luca Hospital, IRCCS Istituto Auxologico Italiano, Milan, Italy. gianfranco.parati@unimib.it
Gianfranco
G
Parati
Miriam
M
Revera
Andrea
A
Giuliano
Andrea
A
Faini
Grzegorz
G
Bilo
Francesca
F
Gregorini
Elisabetta
E
Lisi
Sabrina
S
Salerno
Carolina
C
Lombardi
Carlos G
CG
Ramos Becerra
Giuseppe
G
Mancia
Paolo
P
Salvi
D000086:Acetazolamide / Q000494:pharmacology*; D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000503:physiopathology; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D001916:Brachial Artery / Q000502:physiology; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology*; D017536:Carotid Artery, Common / Q000502:physiology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D010100:Oxygen / Q000097:blood; D013997:Time Factors; D059289:Vascular Stiffness / Q000187:drug effects*
D002257:Carbonic Anhydrase Inhibitors; D000086:Acetazolamide; D010100:Oxygen