How long does it take for claritin (loratadine) to take effect on hives??

Misinformed: Claritin (loratadine) or any other anti-histamine would treat the itch of a rash, but not treat the rash. Are you expecting claritin (loratadine) to treat the rash?

Depends: If not better within 24 hours and you are getting worse, call your physician for and immediate appt or go to the ER

3 days to reach peak: Claritin (loratadine) (loratidine) takes 3 days to reach a steady state, so it could take that long for it to work on hives. Other non-drowsy antihistamines are a better choice: Allegra (fexofenadine) reaches peak effect within 2 hours and Zyrtec (cetirizine) reaches peak effect in 1-2 hours. If you see no benefit at all within 5 hours of taking these, they probably will not work for you.