Not much. Zyrtec is a mixture of two mirror image drugs, levo and dextrocetirizine. Xyzal is a pure levocetirizine. Only the levo form is an active antihistamine. The dextro form is inactive but has no known side effects. The difference is cost, insurance coverage, and patient prejudice or preference.
Is it OK to take 180 mg Allegra in AM and 10m Zyrtec AND Xyzal (levocetirizine) at dinner? Allergist said to take TWO Allegra, but I'm worried it's too much
Mixing antihistamine. Generally, it's best to follow one's doctor's instructions. If not wanting to take Allegra twice a day, and wanting to add a different antihistamine such as Zyrtec or Xyzal (levocetirizine), (levocetirizine) it is probably enough to take Zyrtec or Xyzal (levocetirizine) (one of them instead of both of them). Zyrtec and Xyzal (levocetirizine) are very similar. The makers of Xyzal (levocetirizine) say it is more effective than Zyrtec, but they are similar drugs.
Allergic rhinitis and sinusitis. Went from loratadine claratin To Zyrtec To finally Xyzal (levocetirizine). The first 2 meds didn't help much. Is Xyzal (levocetirizine) more effective?
Allergy treatment. Basically, claritin, loratidine, zyrtec, allegra and xyzal (levocetirizine) are all 2nd generation antihistamines. If your symptoms are not controlled on these, you may need to be given intranasal steroids like flonase, nasonex or other treatments like singular, and also trying regular nasal saline. If still no improvement, time to see the allergist.