My boyfriend took a xyzal at 9am and went for a 61mi. bike ride. he is now experiencing his allergy symptoms again. can he take another xyzal tablet?

Usually ok to do: Plain Zyrtec, Xyzal, Claritin, and Clarinex are single ingredient allergy medications that are taken once a day. Sometimes, a person will find more allergy relief if he takes his medication twice a day. That is usually ok to do if using only one of these 4 medications, but the patient should talk with his doctor, because twice a day would be twice the typical dose.