I have seasonal allergies and I found an effective method for myself:
When I realize the allergies are kicking in (usually after 6 hours of watery eyes and sneezing) I take a claritin and a zyrtec together, as well as spraying my nose with Flonase. Usually this knocks it off and I will keep taking one of the once-a-day meds for a bit to prevent reoccurrence.
Zyrtec and Flonase together is probably the best normal combo and is generally accepted to be ok.
Disclaimers: I'm not a doctor. Combining a nose spray and a pill is generally accepted practice and studied in several peer review studies I've seen. Stacking claritin and zyrtec pills together is not generally accepted practice, so don't do it.
Yes, cetirizine and fluticasone are a good long-term treatment for allergies.
Direct decongestants like pseudoephedrine are of limited use because you quickly develop a tolerance and they become ineffective. With corticosteroid nasal sprays, they work best after consistent use over several days and keep working more or less forever.
Zyrtec and Flonase together is probably the best normal combo and is generally accepted to be ok.
Disclaimers: I'm not a doctor. Combining a nose spray and a pill is generally accepted practice and studied in several peer review studies I've seen. Stacking claritin and zyrtec pills together is not generally accepted practice, so don't do it.