Double-blind randomized multicenter study on the efficacy of trapidil versus isosorbide dinitrate in stable angina pectoris.
BACKGROUND
Trapidil is an inhibitor of phosphodiesterase I-IV with resulting positive lusitropic, vasodilating, and antiplatelet effects.


OBJECTIVE
This study was undertaken to compare the antianginal efficacy of trapidil with that of isosorbide dinitrate (ISDN) in patients with stable angina pectoris.


METHODS
We studied 95 patients with stable angina pectoris who were randomized into a double-blind parallel group study with either oral trapidil or ISDN. After a 1-week run-in period and a 2-week wash-out phase, the patients received either trapidil 200 mg t.i.d. (n = 48) or ISDN 20 mg t.i.d. (n = 47) for 12 weeks. All antianginal medication, except sublingual glyceryl trinitrate (GTN), was discontinued during the study. Patients underwent an exercise electrocardiogram on an ergometer bicycle according to a modified Bruce protocol before and at 6 and 12 weeks during treatment.


RESULTS
The workload capacity increased from 583 +/- 281 W.min before treatment to 833 +/- 444 W.min after 12 weeks of treatment in the trapidil group (p < 0.01) and from 555 +/- 276 W.min to 827 +/- 361 W.min in the ISDN group (p < 0.01). The anginal attacks per week as well as the use of GTN decreased significantly in both groups. After 12 weeks of therapy, the cumulative ST-segment depression during exercise decreased by 67% in the trapidil patients and by 23% in the ISDN patients. Compared with baseline, the double product at the 75 W level was reduced in both groups after 12 weeks of treatment. Blood pressure and heart rate at rest remained nearly unchanged. Overall, no statistical difference was found between the two study groups. The tolerability was good.


CONCLUSIONS
Oral trapidil therapy is safe and effective in stable angina pectoris and is equivalent to standard therapy with ISDN.
Raubach
K H
KH
Medical Academy Sofia, Bulgaria.
Vlahov
V
V
Wolter
K
K
Bussmann
W D
WD
D000284:Administration, Oral; D000787:Angina Pectoris / Q000188:drug therapy* / Q000503:physiopathology; D001794:Blood Pressure; D004311:Double-Blind Method; D004361:Drug Tolerance; D004562:Electrocardiography; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D007548:Isosorbide Dinitrate / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012449:Safety; D014192:Trapidil / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
D014665:Vasodilator Agents; D014192:Trapidil; D007548:Isosorbide Dinitrate