Saline nasal allergy spray called asteoto. it's main ingredient is azelastine hcl. could that show up on my drug test?

No, but sedating: Tons of meds cause false-positive results in drug tests. It depends on the actual testing reagents. Here's just one ex: http://www.pharmacologyweekly.com/articles/drug-classes-cause-false-positive-urine-drug-screen. Be honest reporting all meds, even if they won't show. Your antihistamine drops are considered sedating, so may be prohibited if you are a pilot/ATC. Consider montelukast. Works well.