I take Flonase and Allegra everyday. I take them at the same time when I first wake up in the morning. I do this year round. My allergist also prescribed Singulair to take in conjunction with those two during allergy season but I didn't think it was adding any benefit and removed it from my routine. In the end, Claritin, Zyrtec, and Allegra are all good antihistamine options and are generally well-tolerated. But there are some differences between them, as outlined above, which may make one of these antihistamines better than the others depending on a person's needs and characteristics. Over-the-counter allergy relief medications Claritin (Loratadine) and Zyrtec (Cetirizine) have similar effects, but their ingredients are different, which means different groups of people will have rare but adverse reactions to them. Doctors give trusted answers on uses, effects, side-effects, and cautions: Dr. Sinha on can i take claritin and zyrtec at the same time: These two medications are for the same type of symptoms. Try one at a time and see which suits your better. There would be no benefit from taking both, there may be harm from taking both. Helpful answers from trusted Doctors on causes, diagnosis, symptoms, treatment, and more: Dr. Alves delves into whether or not you should take Claritin and Zyrtec together for symptom relief. Zyrtec and Claritin are both priced about the same. They’re available over the counter, so prescription drug insurance will likely not cover any portion of their expense. However, manufacturer. Claritin (loratadine) is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. I have been on claritin, clarinex, zyrtec and xyzal. I am continuing with zyrtec now becaue of the cost of xyzal ($200/3mo) due to my healthcare selectively removing antihistamines from the formulary.