There are many different causes of post nasal drip. The first and most important is to identify the underlying cause of post nasal drip and treat the cause and remove the cause of post nasal drip if possible. For example correction of anatomical defect (such as deviated nasal septum) by surgery.
Different treatment options are available, such as identification and avoidance of allergens, avoidance of nasal irritants, use of medications, treatment of associated infection, corrective surgery for correction of anatomical defect (if any), immunotherapy (commonly known as allergy shots) etc. Actual treatment involves combination of different treatment options.
Identification and avoidance of allergens:
Allergy literally means “altered reaction” or exaggerated reaction or inflammatory response to a foreign substance. Some common allergens (substances that can cause allergies) are pollen, house dust, mold, dust mites, animal dander (mainly cats and dogs) and certain foods. There is a common saying about allergy and allergens: “every person is allergic to something and everything is allergic to somebody”. It is best to avoid allergens, but it may be very difficult (if not impossible) to avoid allergens (e.g. house dust, pollens etc.). If you are allergic to a food, just avoid it.
Avoidance of nasal irritants:
Tobacco smoke, perfumes, air pollutants, car exhaust, smog etc. can irritate nasal mucosa and mimic allergy, although they do not produce classical immune response seen with allergy. If you are a smoker it is the ideal time and motivation to quit smoking. If you are having problem with air pollution shift to a cleaner and greener area of your city.
Use of medications for treatment of post nasal drip:
For post nasal drip (as well as for allergic rhinitis) the medications used are steroidal nasal sprays (inhalational steroids), antihistamines, nasal decongestants (sprays, drops and oral), and mast cell stabilizers (e.g. cromolyn sodium), leukotriene antagonists, anti-cholinergics and agents that thins mucus.
This is the first line of treatment for post nasal drip. Steroid sprays deliver medication directly to the nose and untoward side effects can be avoided. Steroids are the most potent anti inflammatory medications and suppress all symptoms due to inflammation such as itching, sneezing, runny nose, nasal congestion and post nasal drip. Examples of steroids which are available as sprays are budesonide, fluticasone propionate, flunisolide, beclomethasone, mometasone furoate etc.
Sometimes oral (systemic) steroids may be required for management of post nasal drip and rhinitis, when steroid sprays can not control symptoms adequately.
Antihistamines for treatment of post nasal drip:
One of the most common inflammatory mediators is histamine and antihistamines are used frequently for treatment of post nasal drip. Non sedating antihistamines (such as fexofenadine, cetirizine) are commonly used for this purpose. Sedating antihistamines should be avoided if a person needs to drive or operate machinery.
Nasal decongestants in treatment of post nasal drip:
Nasal decongestants such as oxymetazoline, xylometazoline, phenylephrine etc. are commonly used for treatment of post nasal drip, as drops, nasal sprays and tablets (pseudoephedrine). They reduce nasal congestion and nasal secretion and provide symptomatic improvement. However oral formulations should be avoided in patients with hypertension, heart diseases, thyroid problems, glaucoma etc.
Mast cell stabilizers in treatment of post nasal drip:
Cromolyn sodium helps in stabilizing mast cells, which are storehouse of histamine (important mediator of allergy and inflammation). By stabilizing mast cells, they do not allow escape of histamine from mast cells and allergy/inflammation is prevented. They are mainly used as preventive measures. Once inflammation has set in, they can not stop it.
Leukotriene antagonists in treatment of post nasal drip:
Leukotriene antagonists (such as montelukast) oppose the action of leukotriene, an important inflammatory/allergy mediator.
Agents that thins mucus:
They are sometimes used in treatment of post nasal drip. They make nasal secretions (mucus) this and less sticky/viscid which helps in easy passage. Guaifenesin is one such commonly used agent. Drinking adequate amount of water is important to keep mucus thin.
Immunotherapy for treatment of post nasal drip:
If allergen can be identified, small amount of allergen is given to the individual repeatedly to desensitize him/her. Introduction of allergen repeatedly to sensitive person will interfere with allergic response and the person will develop antibodies against the allergen and become less sensitive to the allergen. This is a risky process and may not be effective if a person is allergic to more than one allergen.
Surgery for treatment of Post Nasal Drip:
If post nasal drip is due to anatomical defect (e.g. deviated nasal septum), corrective surgery can give lasting benefit in case of chronic post nasal drip. If there is any anatomical defect the problem of post nasal drip is usually chronic and may lead to chronic cough, sore throat etc.
Sometimes post nasal drip or rhinitis may be associated with infection, which need appropriate antibiotic therapy.
Generally a combined approach is used for treatment of post nasal drip. Preventive and symptomatic management is commonly used together for best result.