Any advantages of xyzal over cetirizine in terms of side effects, physicochemical properties of drug?

Question

Any advantages of xyzal over cetirizine in terms of side effects, physicochemical properties of drug?

Answer 1

The short answer is no, not really.

The long answer is that because levocetirizine (Xyzal) is just the levo- enantiomer of cetirizine (Zyrtec), it has a slightly different pharmacokinetic/dynamic profile.

From what I can gather from a brief review of the literature, it's half-life is longer (due to less hepatic metabolism) and it's overall anti inflammatory effects may last longer. However, although levocetirizine has higher potency for H1 receptors, doses are generally adjusted down to prevent sedation. Levocetirizine is primarily excreted renally; dose adjustment in renal impairment is needed, similar to cetirizine.

There is a suspicious lack of direct comparison between Xyzal and Zyrtec for treating allergies and urticaria, which is somewhat telling. The few that do make a direct comparison find either minimal or no differences between the two in terms of instantaneous symptom relief. The cost of the medication will probably outweigh any benefit in patient outcomes. Unless, of course, the copay for Xyzal is less than OTC cost of Zyrtec.