zyrtec 10mg.

You can take Zyrtec at whatever time of day you want. Keep in mind that one of the side effects are dizziness and drowsines, so you might consider taking it late in the day when you don't have to be as alert. (And make sure you know how you react to this medication before you drive, etc). Yes, you can "make" Zyrtec-D if you cut the Zyrtec in half and use a 120mg extended release pseudoephedrine product. The absorption will not be affected so there is absolutely no problems with doing this.