Sinus Pressure and Tamoxifen

[Freakzilla]

Hi,

My girlfriend is on Tamoxifen. Recently she has been experiencing bad sinus headaches. She also gets hayfever. When she is inside, she is fine, it's when she goes outside during the day. She is currently taking Sudafed Pressure and Pain capsules and Claritin. They seem to work. Is it worth trying a Sudafed nasal spray. Any other ideas please?

Is there anything else anyone could recommend. I know you can't use Benadryl with Tamoxifen.

Thanks