(2007), there existed no reviews on the efficacy of phenylephrine as a metabolized decongestant. With legal conditions invoking its use thusly as early as 2002, it should be seen as surprising, problematic and irresponsible on the part of drug companies to actively work to promote this as a replacement for pseudoephedrine. Thus, all indications from the research are that those seeking to treat cold and flu symptoms will be better served by purchasing the behind-the-counter pseudoephedrine-based treatment rather than over-the-counter phenylephrine-based substitutes. Works Cited:

The Advanced Light Source (ALS). (2008). P-Glycoprotein Structure and Chemotherapy Resistance. www.als.lbl.gov.

Bylund, D.B.; Bond, R.A.; Eikenburg, D.C.; Hieble, J.P.; Hills, R.; Minneman, K.P. & Parra, S. (2009). Adrenoceptors: 1A-adrenoceptor. IUPHAR database. Online at http://www.iuphar-db.org/GPCR/ReceptorDisplayForward?receptorID=2175.

Cerner Mulum, Inc. (CMI). (2009). Phenylephrine. Drugs.com.

Eccles, R. (2007). Substitution of phenylephrine...

An illogical way to control methamphetamine abuse. British Journal of Clinical Pharmacology, 63(1), 10-14.
Hatton, R.C.; Winterstein, a.G.; McKelvey, R.P.; Shuster, J. & Hendeles, L. (2007). Efficacy and Safety of Oral Phenylephrine: A Systematic Review and Meta-Analysis. The Annals of Pharmacotherapy.

Homewood, L. (2006). UF Researchers Question Effectiveness of Decongestant. University of Florida News. Online at http://news.ufl.edu/2006/07/19/decongensant/

Medicines Classification Committee (MCC). (2004). Classification of Medicines. Medsafe. Online at http://www.medsafe.govt.nz/Profs/Class/mccMin25Nov2004.htm

National Institutes of Health (NIH). (2009). Phenylephrine. Medline Plus. Online a t http://www.nlm.nih.gov/medlineplus/druginfo/meds/a606008.html

Treatment Action Group (TAG). (2000). What's This About P-Glycoprotein? The Body. Online at http://www.thebody.com/content/art1660.html

Wikipedia. (2009). Adrenergic receptor. Wikimedia, Ltd. Inc.