Adenosine as a vasodilator in primary pulmonary hypertension.
BACKGROUND
The acute administration of vasodilator drugs to patients with primary pulmonary hypertension has been advocated to identify those with reversible pulmonary vasoconstriction. Unfortunately, the usefulness of the drugs currently available is limited by accompanying systemic hypotension. A vasodilator with effects confined to the pulmonary circulation would therefore be advantageous in such patients.


RESULTS
The purine nucleoside adenosine was infused into the pulmonary artery in seven patients with primary pulmonary hypertension (baseline pulmonary vascular resistance [PVR], 442-1,295 dyne/cm/sec-5) to determine its effect on PVR. In all patients, there was a dose-dependent and significant reduction (mean maximal percent decrease from baseline, 38.9%; p less than 0.001) in PVR mediated through a decrease in pulmonary artery pressure and an increase in cardiac output. Systemic vascular resistance (SVR) also decreased, but the ratio of PVR to SVR decreased (maximal mean percent decrease from baseline) by 10.5% (p less than 0.025), indicating that adenosine has a preferential vasodilator effect on the pulmonary circulation when administered in this manner.


CONCLUSIONS
Because of its pharmacokinetic and vasodilator properties, adenosine may have a specific role in the investigation of primary pulmonary hypertension.
Morgan
J M
JM
Department of Thoracic Medicine, Royal Brompton and National Heart Hospital, London, UK.
McCormack
D G
DG
Griffiths
M J
MJ
Morgan
C J
CJ
Barnes
P J
PJ
Evans
T W
TW
D000241:Adenosine / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D007261:Infusions, Intra-Arterial; D008297:Male; D011652:Pulmonary Circulation / Q000187:drug effects*; D014655:Vascular Resistance / Q000187:drug effects*; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D000241:Adenosine