Hello, I'm here to sell you Allegra D, and Xyzal, but not Allegra or Zyrtec!

Implications: Take Zyrtec and sort out the right-handed molecules from the lefties.  Send all the lefties home, and you have levocetirizine, a.k.a. Xyzal.  Like Zyrtec, Xyzal is owned by UCB http://www.ucb-pharma.com/products/ .  But unlike Zyrtec, Xyzal will not be marketed by Pfizer.  Instead, UCB has enlisted sanofi-aventis, the company that brought Seldane, and then Allegra, to market        

Analysis: Nowadays, Allegra has gone generic, but sanofi-aventis continues to promote Allegra-D 12 hour and Allegra-D 24 hour.  (The 'D' products have pseudoephedrine <Sudafed> added, to help treat stuffy noses and sinus pressure)

In another month or so, they'll still have those 2, but they'll also have Xyzal!  Maybe they'll sell off the Allegra line when Xyzal gets a Xyzal-D?

How unusual.

Is Xyzal an improvement over Zyrtec?  Not really.  Maybe it's a bit less sedating than Zyrtec, but the bottom line is, both Zyrtec and Xyzal have a better chance of making you sleepy than placebo, and that will hurt Xyzal.

A few years ago, The Medical Letter, a well respected review of drugs, said that Allegra was the best overall choice of antihistamines.  It is stronger than Claritin or Clarinex, almost as strong as Zyrtec, and won't make you sleepy.  These days, it's available as a generic, and that's why generic Allegra (fexofenadine) is the #1 antihistamine I prescribe.

Meanwhile, if Claritin works for you, get it as cheaply as you can.  It's generic, loratadine 10 mg, is available in bottles of 300 pills for $11.00 at Sam's Club or Costco.  That's about 3 cents per pill.