As you may know, Claritin has been OTC in the United States for awhile now. The repercussions of this is that competing brands such as Allegra and Zyrtec have been pushed to the most expensive co-pay tier in many drug plans. This is especially of concern for those who are not on a tiered drug plan. It has been my experience that some allergy sufferers do not respond well to Claritin but respond to some of the other brands.
In Canada, Allegra and Zyrtec are OTC, so patients may want to consider using Canadian pharmacies. Compare the prices for 30 tabs of 10mg Zyrtec: US: $58.99 vs Canada (OTC) $19.99. Quite the difference.