RT Journal Article
SR Electronic
T1 Evaluation of the Use of Accelerated Infusions for the Determination of Pharmacokinetic Linearity
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 468
OP 479
VO 293
IS 2
A1 Keith W. Ward
A1 Robin Griffiths
A1 Mark A. Levy
A1 Brian R. Smith
YR 2000
UL http://jpet.aspetjournals.org/content/293/2/468.abstract
AB Accelerated infusions are potentially useful in the investigation of pharmacokinetic linearity. However, little information exists to validate this technique or to demonstrate its limitations. This investigation was performed to determine whether accelerated infusion regimens reliably estimate the range of pharmacokinetic linearity for molecules of varying pharmacokinetic properties, to evaluate the ability of accelerated infusions to identify pharmacokinetic nonlinearity, and to validate the accelerated infusion technique using compounds with known pharmacokinetic parameters. Simulations incorporating accelerated infusion as the input function resulted in the anticipated concentration-time profiles that contained an initial lag phase before reaching a linear slope. This lag phase increased with increasing distributional volume and in some instances was sufficiently great to obscure or prevent the linear portion of the profile. These simulations also revealed that clearance estimated from the apparently linear portion of the concentration-time profile can be erroneous under some conditions, as for large-volume compounds. Simulations of structured nonlinearity produced the predicted profiles for compounds with low to moderate volumes of distribution while demonstrating that modeling of data derived from compounds with large volumes of distribution may be inaccurate. Finally, experiments using accelerated infusions with various test compounds further demonstrated the usefulness of this technique while presenting limits imposed on the interpretation of the data. The results of this investigation indicate that the accelerated infusion may be used to determine pharmacokinetic linearity for compounds within certain pharmacokinetic boundaries, but that appropriate caution should be exercised in the extent of interpretation that should be extracted from such studies. The American Society for Pharmacology and Experimental Therapeutics