Clinical pharmacokinetics after a single oral dose of oxilofrine

In a combined pharmacokinetic and clinical trial the correlation was investigated between plasma levels of oxilofrine and the haemodynamic effects on eight healthy volunteers after an oral dose of 120 mg oxilofrine. Plasma levels of free oxilofrine were measured by capillary gas chromatography mass fragmentography. Cardiovascular as well as echocardiographic parameters (left ventrical extent and velocity of fractional shortening) have been measured. The results pharmacokinetically showed a marked enterohepatic reabsorption profile with a second oxilofrine plasma peak occurring in between the second and third hours. The heart rate and mean arterial blood pressure remained unchanged. The total peripheral resistance was deceased on average. Systolic blood pressure increased by a maximum of 13.8%, the diastolic decreased by 8.8%. Increasing of the extent of left ventrical fractional shortening by 20.9% and the velocity by 29.5% indicated a positive inotropic effect, which was long lasting and not accompanied by chronotropic effects. There is a direct positive correlation between oxilofrine plasma levels and the extent of fractional shortening of left ventrical diameter (r = 0.981).