front |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 |11 |12 |13 |14 |15 |16 |17 |18 |19 |20 |21 |22 |23 |24 |25 |26 |27 |28 |29 |30 |31 |32 |33 |34 |35 |36 |37 |38 |review |
To understand nicotine pharmacology, it’s
important to know that absorption of nicotine is pH dependent. Because
nicotine is a weak base (pKa = 8.0): In acidic media… nicotine is ionized and poorly absorbed across membranes. In alkaline media… nicotine is nonionized and well absorbed across membranes. Under physiologic conditions (pH = 7.3–7.5), approximately 31% of nicotine is nonionized and readily crosses cell membranes (Benowitz, 1992; Hukkanen et al., 2005). Benowitz NL. (1992). Cigarette smoking and nicotine addiction. Med Clin N Am 76:415–437. Hukkanen J, Jacob P III, Benowitz NL. (2005). Metabolism and disposition kinetics of nicotine. Pharmacol Rev 57:79–115. Slide is used with permission, Rx for Change: Clinician-Assisted Tobacco Cessation. Copyright © 1999-2007 The Regents of the University of California, University of Southern California, and Western University of Health Sciences. All rights reserved. |