Page 76 - Medicinal Chemistry Self Assessment

Section 2 Whole Molecule Drug Evaluation

1.19 Lidocaine

As a sodium channel blocker, lidocaine has found therapeutic use both as a local anesthetic and as a Class IB anti-
arrhythmic agent. As an anesthetic, this agent demonstrates rapid onset of action (acts quickly) and a longer dura-
tion of action (lasts longer) than most amino ester-type local anesthetics. The most frequently observed side effects
are changes in the central nervous system (CNS) (e.g. dizziness, lightheadedness, tinnitus). Lidocaine is extensively
metabolized by the CYP1A2 isozymes to a variety of metabolites.

1. Conduct a complete structural evaluation of ow.
1. Conduct a complete structural evaluation of lidocaine, place your answers in the grid provided, and then

use the evaluation information in the grid to inform your answers to some of the questions that follow.
CH 3 CH 3
O
N CH 3
N

CH 3 H

Lidocaine

Lidocaine
Function
Character
Amino Acids That
Acidic,
4 Unless place next to the relevant arrow. Function Can Interact with
Basic, Interaction(s) the Functional
Character or Neutral Function Possible with Group via Hydrogen
Name of Hydrophilic Provide ↑ Solubility Biological Target Bonding Interac-
Functional and/or pK When and/or at Physiological tions at pH=7.4
a
Group Hydrophobic Relevant ↑ Absorption pH=7.4 None Is Acceptable

2. Based on the information in the structure evaluation grid, determine whether or not lidocaine is likely
soluble in the blood (pH=7.4).

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