The really old hay fever medicine like a decade ago would make you drowsy, the current stuff is Cetirizine and Loratadine which isn't supposed to make you drowsy although I found Loratadine did. Cetirizine doesn't work for me any more though, it lasts a couple hours then I'll be sneezing again and the guidelines say not to take more than 1 a day.
Nowadays you can get antihistamine or steroid nasal spray or fexofenadine tables which a newer antihistamine, they're technically OTC or prescription only but you can get it online quite easily. I've been using the steroid nasal spray which takes 2 weeks to start working but I've had no runny nose since I start, only problem is that I get itchy eyes so I'm gonna need to double up with a tablet when I go punting