Both companies have extended their brands into new eye-drops products, but despite carrying the Zyrtec and Claritin names neither eye-drops brand contains any of the drugs that consumers know as Zyrtec or Claritin.
The drug in Schering's Claritin pills is loratadine, but Claritin Eye contains ketotifen, not loratadine. The drug in McNeil's Zyrtec pills is cetirizine, but Zyrtec Itchy Eye Drops contains ketotifen fumarate, not cetirizine. A note on the Zyrtec web site says:
The ingredients and uses of this product are different than other ZYRTEC products.The Claritin web site only distinguishes the products when you click to look at the ingredients label.
Messages left for McNeil and Schering were not immediately returned. The obvious question: Was it a good idea for the FDA to approve two different drugs under the same name?
Disclosure: The author is a longtime Claritin user.