I would avoid just taking the general sinus meds, like sinutab and the likes.
All these drugs do is dry out and harden our sinus cavities and this may not remove the problem all together.
You need to get some antibiotics just incase, this will help any infection in the upper cavities which causes the drips..
What i do is a mix a saline solution, a little pinch of salt, some luke warm water and some bicarb of soda. The bicarb helps break down the mucas and the salt helps clean infection.
There is a trick to taking this though. You need a straw, suck up some solution, just a bit, block the bottom of the straw with your thumb to stop it running out. Get down on ur knees and put the crown of your head on the floor so your nostrils are facing the roof.
Then gently let the solution out of the straw into ur nose, letting it run down the bridge of your nose into your upper cavities(which kinda sits above your eyes and behind in your brow). Give it a few seconds to get in there and move around, then grab a tissue or watever and let it out. Often a little blow helps.. Rinse and repeat.
This might sound a bit strange and over the top but it WORKS. Ive been to many nose doctors and well this is the best advice. I live with sinus problems daily, and once a year i have an attack when the weather changes. These attacks leave me partially blind in one eye because of the pain. Using general meds just make it worse.
My dad has just recently had to have holes drilled into his forehead to let some of his 'problem' out. I feel im going down the same road.
I try and use daily spray as well, called Flexinase, this is reletively mild, keeps heyfever away and inturn sinus problems.