Hello,
Drainage down the throat also known as
Post nasal drip can occur due to causes like Sinusitis, Upper
Respiratory Tract infection,
acid reflux, allergies et cetera.
I would suggest you to consult an Otolaryngologist and get evaluated and a thorough clinical evaluation and investigations like PNS View x ray, nasal endoscopy, and an Allergy test can be done for confirmation.
In case of infection you can be advised to take a course of antibiotics, ant-inflammatory painkiller, decongestants oral as well as
nasal spray, anti-allergic and mucolytic. As of now, you can take anti allergic like
Levocetirizine, Mucolytic like Ambroxol.
In case of allergies, anti-allergic and preventing exposure to allergen can be advised. Do warm saline gargles and steam inhalations. Limit exposure to dust and also avoid chilled foods and sip on warm water.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. Honey Arora