Can you take Claritin (loratadine) and atarax together?

Yes for hives. Claritin (loratadine) in the morning and Atarax at bedtime is a good combination for treating hives. The Atarax can be used as an as needed if hives breakthough in the evening and make it hard to sleep. Remember that the drowsiness & delayed reaction time caused by Atarax may still be present the next morning. If you need two antihistamines to control hives you should be under a physician's care.
Yes, but... While there is no direct medication interaction, that is a lot of antihistamine. I wouldn't advise the combination and would probably do allergy testing (immunecap blood testing specific for your area) to see if you really need that much antihistamine or if a symptom centered combination would be more beneficial.

Related Questions

I have taken 10mg loratadine and a fluticasone propionate nasal spray. In the same day can I take Atarax for help sleeping?

Mixing meds. There should be no issues taking Atarax (hydroxyzine) along with Loratidine (Claritin) and fluticasone (nasonex). The Loratidine is a non sedating anti histamine where as the atarax is a sedating one - that has been used off label for sleep. No issues - and if any should arise stop the Atarax.