Hemodynamic effects of pirmenol and lidocaine: a placebo-controlled, double-blind, comparative study.

The acute hemodynamic effects of pirmenol and lidocaine were studied in a double-blind, placebo-controlled investigation. Thirty patients undergoing catheterization received one of the following: pirmenol as a 50-mg intravenous bolus injection followed by a 2.5 mg/min infusion, lidocaine as a 75-mg intravenous bolus injection followed by a 3 mg/min infusion or placebo administered in a similar fashion. Mean plasma pirmenol concentrations during steady infusion were 2.3 to 2.4 mg/liter, and mean plasma lidocaine concentrations were 16 to 24 mumol/liter. Pirmenol increased heart rate from baseline by 10 beats/min (p less than 0.001) and mean arterial pressure by 5 mm Hg (p less than 0.001), with similar increases in systemic (p less than 0.05) and pulmonary vascular resistance (p less than 0.01). Lidocaine induced a comparable increase in mean arterial pressure (6 mm Hg, p less than 0.001), but unlike pirmenol, it increased left ventricular and diastolic pressure by 2.8 mm Hg (p less than 0.05). Indexes of left ventricular work were not affected by either drug. Echocardiographic ejection fraction was reduced more by pirmenol (-0.05, p less than 0.0001) than by lidocaine (-0.03, p less than 0.05), a difference that may be related to the changes in heart rate. Side effects were not observed in any patient. The myocardial depressant effect of pirmenol is relatively slight and comparable to that of lidocaine.