Last week i had sinus issues and it resolved. this week i was kept up with a post nasal drip cough. i took 2 zyrtec and 1 tessalon pearles to sleep.

Flonase. : You can also try Flonase. It might be that you are battling sinus allergies or perhaps a mild infection. The majority of sinus infections we treat conservatively, without any antibiotics.

See below: If you're having post nasal drip, the first generation antihistamines work much better for cough - like chlorphenirimine, than the second generation ones like zyrtec. Try that and see if it doesn't help.