Sinus Allergy Solutions Wanted

After a couple of hours of difficulty exhaling nasally during the middle of the night last night it occurred to me that I still needed to take anti-histamines. (Duh! Before starting CPAP it was before bedtime and during the early morning hours, but I'd done so well recently that I'd just forgotten to take any during the middle of the night. Guess the sleep just felt so good.) My higher pressures of the past couple of nights have exacerbated this previously known problem though.

So what's the best way to cope with this. I'd like to hear what good solutions people have found. It seems to be purely allergy related in my case, as a sinus irrigation in the middle of the night had absolutely no effect. The congestion did resolve shortly after taking anti-histamines though.

Regards,
Bill