Pseudoephedrine helps with some sinus issues but isn't an antihistamine. There are a cocktail of allergy meds that help, but are not fast acting so I need to be

Pseudoephedrine helps with some sinus issues but isn't an antihistamine. There are a cocktail of allergy meds that help, but are not fast acting so I need to be on them all the time to account for one-off exposures. They don't stop the allergic reaction entirely but they do make it more bearable and buy me time - with those built up in my system I can generally be around animals for about 4 hours before my allergies become unbearable.