I know you can take Claritin---I had my CIL stuff completed in July 2017 and was taking Zyrtec at the time. The FAA doctor that did my ekg, etc. advised I couldn't take Zyrtec because it makes you drowsy for up to 48 hours after taking a single dose. Claritin/D non-drowsy is on the FAA approved list according to the info I received. However, claritin didn't do much for me, personally. I ended up receiving allergy acupuncture treatments (5 sessions) and haven't had to take any allergy medication since end of November.