The oral dopamine agonist, ibopamine, in normal man: effects on rhythm, heart rate, blood pressure and catecholamines.

To evaluate the effects of the oral aselective dopamine congener ibopamine, heart rate, blood pressure, cardiac rhythm, electrocardiographic (ECG) parameters and plasma catecholamines were studied in ten healthy subjects on three occasions: without medication, after 100 mg oral ibopamine and after combined treatment of ibopamine and the dopamine antagonist metoclopramide. Ibopamine was well tolerated by all subjects. No significant changes in heart rate or blood pressure were seen during either ibopamine alone or during concomitant metoclopramide administration. In addition, there were no differences in PR-, QRS- and QTc- intervals on the ECG and plasma norepinephrine, epinephrine and dopamine levels were unchanged. None of the ten volunteers showed proarrhythmia from ibopamine. However, in one subject, episodes of accelerated idioventricular rhythm were observed after ibopamine, which were asymptomatic and did not exceed a rate of 51 beats/minute. During concomitant metoclopramide infusion, ibopamine did not induce accelerated idioventricular rhythm. In conclusion, in healthy subjects ibopamine appears to be a safe drug and causes neither proarrhythmia, nor changes in heart rate, blood pressure, ECG-parameters, or plasma catecholamines.