This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
To the Editor:
We read with interest the report by Citerio et al.1 describing the genetic profile of a patient with presumed phenytoin (PHT) slow metabolism. We are concerned that the plasma concentration/time data provided by the authors do not support the hypothesis of the patient truly having slow PHT metabolism phenotype. Alternate explanations for these data are more likely.
First, a plasma concentration of 79 mcg/mL within 2 hours of a 15 mg/kg PHT loading dose primarily reflects dose size and volume of distribution, and only minimally reflects rate of metabolism.2 The data presented suggest that the patient had a very small volume of distribution, a laboratory error, or, more likely, that the patient received an incorrect dose of PHT. Second, a patient with a typical PHT metabolic rate would require 8 days for the plasma concentration to drop from 79 to 10 mcg/mL based on data generated from a Bayesian PHT dosing program we have tested extensively.3,4⇓ We entered the patient data (extrapolated from the graph provided) presented by the authors into our modeling program and estimated a Km of 5.8 …
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Letters: Rapid online correspondence
REQUIREMENTS
You must ensure that your Disclosures have been updated within the previous six months. Please go to our Submission Site to add or update your Disclosure information.
Your co-authors must send a completed Publishing Agreement Form to Neurology Staff (not necessary for the lead/corresponding author as the form below will suffice) before you upload your comment.
If you are responding to a comment that was written about an article you originally authored:
You (and co-authors) do not need to fill out forms or check disclosures as author forms are still valid
and apply to letter.
Submission specifications:
- Submissions must be < 200 words with < 5 references. Reference 1 must be the article on which you are commenting.
- Submissions should not have more than 5 authors. (Exception: original author replies can include all original authors of the article)
- Submit only on articles published within 6 months of issue date.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- Submitted comments are subject to editing and editor review prior to posting.
