allergic rhinitis
"Thank you chlorpheniramine! After 4 years of daily suffering with the mysterious 'chronic phlegmitis' that no doctor or internet forum could answer, I found this by accident and to date has been the only thing to positively affect and practically halt the terrible constant post nasal drip. No other antihistamines or steroid sprays or mucolytics or decongestants touched it. And it has the added bonus of potentiating my pain medicine for chronic pain. So I thought I was in heaven one day to find less pain and the post nasal drip decreased."