In case anyone else is having this problem (antihistamines + winter + hypothyroidism = extreme dryness for me!) I thought I would pass along a few solutions I've found that seem to be helping...

- Saline nasal spray
- Biotene mouth spray (reaches the back of my throat)
- Biotene mouth gel (seriously moisturizing)
- Ketotifen eye drops

The worst time for me is at night.  The dryness was actually interfering with my sleep  I've been using all of these tricks right before I go to bed.  So far, so good!  Last year I was able to cut back on my H1s for the winter, but not this year... too much nausea.

Heather

If using saline nasal rinses, be sure to use distilled water to mix the solution or use a commercial one, such as Ocean.

Heather:
This may  sound goofy, but I found for the nasal drying using a lip balm & putting in my nose & rubbing it all around works great for me. I carry one around with me. The rounded shape of it seems to get all the areas of the passage. I like the medicated ones, not the flavored ones. Just something that works for me. The spraying saline solutions like ocean didn't seem to do anything. For eye drops I use the Refesh brand. Tears at night, gel during the day for me works best. If things get bad I use prescription Pataday-it flat out works & works fast, but expensive.
PS: thanks for the liquid benedryl tip. I use it at night now & it seems to stop  most night skin pain sessions that would wake me up. Amazingly the tablets didn't work in fact not sure if it didn't make things worst. Good luck with the dental work, when I had crowns done didn't cause any issues.
Hope to make it to Indy this year again. Will PM you with details if works out that I come.
Mike V