I’ve been experiencing persistent post-nasal drip for a couple of months, exclusively on my right side. I had a sphenoidectomy on my right side about 4 years ago, and my nose hasn’t caused me much problems since, except for the recent post-nasal drip. I am using steroid nasal sprays twice a day and taking antihistamines from my GP (Zyrtec, Telfast or chlorpheniramine), but the post-nasal drip doesn’t seem to get better. Could this be related to the sphenoidectomy, or is it just rhinitis? What else can I do besides the spray and antihistamines?