[The noninvasive quantitative evaluation of the acute hemodynamic effects of sublingual and transdermal nitroglycerin in man].
BACKGROUND
Organic nitrates are complex vasodilators: the hemodynamic action of these drugs is different in the venous and arterial resistance and capacitance beds. The aim of our study was to obtain a quantitative, noninvasive evaluation of the acute effects of sublingual and transdermal (td) nitroglycerin (NTG).


METHODS
Twenty-one pts (mean age 49 years) underwent strain-gauge plethysmography and digital photoplethysmography under control conditions, 5 min after sublingual NTG (0.4 mg), 1 hour thereafter and 2 hours after NTG td (10 mg patch). Forearm venous capacitance (CV, ml.100 ml-1) and arteriolar resistance (RA, mmHg.ml-1.100 ml.min) and the b/a ratio of arterial pulse wave (%) were measured.


RESULTS
After sublingual NTG, CV increased (+24%, p < 0.01) and b/a was reduced (-35%, p < 0.01), while heart rate and RA increased (+9% and +36% respectively, both p < 0.01). Two hours after NTG td, CV increase was not statistically significant (+11%, p = 0.056), b/a was reduced (-31%, p < 0.01), heart rate and RA did not change.


CONCLUSIONS
The combined use of plethysmography and digital photoplethysmography is suitable for the evaluation of vasoactive drugs such as nitrates, which have a complex profile of action on arterial and venous beds. By this method we have shown that NTG td 10 mg dilates venous beds to a low extent; this approach will be utilized in future studies aimed at elucidating dose-response and regimen effect of these drugs.
Pizzetti
F
F
Divisione di Cardiologia, Ospedale S. Spirito, Casale Monferrato.
Peci
P
P
Manni
B
B
Bonaglia
M
M
Ghio
S
S
Latini
R
R
Avanzini
F
F
D000279:Administration, Cutaneous; D000286:Administration, Sublingual; D000328:Adult; D000368:Aged; D003327:Coronary Disease / Q000188:drug therapy / Q000503:physiopathology; D005260:Female; D005542:Forearm / Q000098:blood supply; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage* / Q000494:pharmacology; D010991:Plethysmography / Q000379:methods
D005996:Nitroglycerin
Valutazione quantitativa non invasiva degli effetti emodinamici acuti della nitroglicerina sublinguale e transdermica nell'uomo.