Pharmacokinetics of exogenous adenosine in man after infusion

Summary

The plasma kinetics of adenosine was investigated in healthy volunteers after a 1 minute infusion of 2.5, 5 and 10 mg (38, 79 and 148 μg·kg⁻¹ respectively) and after infusion of 200 μg·kg⁻¹ in 10 min followed by 400 μg·kg⁻¹ in 10 min.

As the dose in the 1 min infusion study was increased the mean CL of adenosine decreased (10.7, 4.70 and 4.14 l·min⁻¹, respectively), its mean half-life increased (0.91, 1.24 and 1.86 min, respectively), and the mean volume of distribution did not show any clear trend (8–13 l).

After the 20 minute infusion the plasma level of adenosine reached a peak value comparable to that observed after infusion of 5 mg in 1 min (about 0.5 μg·ml⁻¹), but the mean clearance and half-life were significantly different (12.1 l·min⁻¹ and 0.63 min respectively).

In all the subjects the plasma concentration of adenosine had returned to the baseline value in 5–15 min after the end of the infusion.