April 4, 1977

Pharmacokinetics of Lidocaine

Author Affiliations

Veterans Administration Hospital Portland, Ore

JAMA. 1977;237(14):1433. doi:10.1001/jama.1977.03270410033005

To the Editor.—  This letter refers to the article "Pharmacokinetic Approach to the Clinical Use of Lidocaine Intravenously" (236:273, 1976) by Greenblatt et al. I would like to call attention to a possible problem with the data on which they base their approach.Greenblatt and colleagues base their analysis on the data in an article by Rowland et al.1 Unfortunately, Rowland and his colleagues did not do a least-squares regression of the distribution volume versus body weight; they instead assumed a 0 intercept and divided by body weight. Figure 1 is a least-squares regression of their data which I did of body weight versus distribution volume. The dashed line is the least-squares plot; the solid line is the plot that Rowland et al assumed and on which the article by Greenblatt and colleagues is based. It is clear that the solid line is not justified by the data. Yet