[A study on tolerance to denopamine, oral beta 1-agonist].
To investigate whether effects of denopamine become weaker or not. Initial single dose (10 mg) effects, single dose effects after long-term treatment (30 mg per day, about 40 days), and chronic effects were studied by Doppler and echocardiography in 23 patients with heart failure (NYHA II-III). 1) Chronic effects: Blood pressure and heart rates didn't change significantly whether they were measured before or after long-term treatment. But left ventricular end-diastolic dimension decreased from 54.6 +/- 10.2 to 53.3 +/- 10.1 mm (p less than 0.01). Percent fractional shortening (%FS) increased from 22.6 +/- 7.8 to 25.3 +/- 8.6% (p less than 0.05). Mean velocity of circumferential fiber shortening (mVCF) tended to increase, and cardiac index (CI) increased from 2.71 +/- 0.47 to 2.98 +/- 0.57 l/min/m2 (p less than 0.01). 2) Initial single dose effects: Blood pressure and heart rates increased significantly. %FS increased from 25.0 +/- 7.7 to 25.9 +/- 7.8% (p less than 0.05), mVCF increased from 0.94 +/- 0.26 to 1.03 +/- 0.28 cir/sec (p less than 0.01), and CI increased from 2.81 +/- 0.49 to 3.09 +/- 0.49 l/min/m2 (p less than 0.01). 3) Single dose effects after long-term treatment: Blood pressure and heart rates increased significantly. %FS tended to increase, mVCF increased from 1.02 +/- 0.27 to 1.09 +/- 0.30 cir/sec (p less than 0.05), and CI increased from 3.05 +/- 0.62 to 3.37 +/- 0.54 l/min/m2 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Hondo
T
T
First Department of Internal Medicine, Hiroshima University School of Medicine.
Kawagoe
T
T
Morichika
N
N
Nakagawa
H
H
Yamagata
T
T
Yuasa
A
A
Tsuchioka
Y
Y
Matsuura
H
H
Kajiyama
G
G
Okamoto
M
M
D000284:Administration, Oral; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage*; D000368:Aged; D004361:Drug Tolerance; D015150:Echocardiography, Doppler; D004983:Ethanolamines / Q000008:administration & dosage*; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged
D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; C037293:denopamine