Intravenous clonidine in acute myocardial infarction in men.

We studied the effects of intravenous clonidine treatment in a group of 24 patients with acute myocardial transmural anterior and/or lateral wall infarction. Clonidine, known as an antihypertonic agent, was administered as a bolus of 1-2 micrograms/kg body weight and repeated every 2-3 hr. However, maximal range of the time interval was 20 min to 4 hr, maximal range of doses 37 to 150 micrograms, depending on the hemodynamic status. The effects were measured by precordial electrocardiographic mapping as well as serial creatine phosphokinase determinations. A big decrease in ST-segment elevation was observed: sigma ST reduction after 24 hr was 37% of initial value (140% in control group), after 48 hr - 30% (120% - control); NST fall after 24 hr - 45% (145% - control), after 48 hr - 41% (142% - control). NQ increased after 24 hr to 135% of initial value (156% - control), after 72 hr to 137% (167% - control). Detailed analysis revealed undoubted correlation between the dosage and favourable dynamics of precordial mapping parameters. Hemodynamic, antiarrhythmic and above all adrenolytic activity were noted. The treatment caused a distinct deterioration in daily adrenalinuria mean values to 5.99 micrograms in the first day (14.20 - control) and lower in the following days. No side effects were observed but sudden discontinuation of the therapy caused an unfavorable reaction. A temporal association between diminished adrenalinuria and both clinical improvement and limitation of infarct size was observed. Therapy with intravenous clonidine requires meticulous individualization of clonidine dosage depending on the patient's initial hemodynamic status.