<s>[INST] My son (19) has been experienceing morning nausea for about 6 months. He complains about extra mucus on his throat which can cause vomiting . Drs have recommended trying over the counter allergy medicine. Claritan Reditabs helped somewhat but do not take the symptoms away completely. Should he try the behind the counter version of Claritan? [/INST] HI Extra mucus in the throat/ post nasal drip is one of the symptoms of rhinitis or sinusitis (though sinusitis also associated with pain over the cheeks and by the frontal sinus at the forehead, redness of nose ,cheeks or eyelids). There are other causes of postnasal drip but they are not as common, they include: as result of medication, deviated nasal septum. Treatment of allergic causes of postnasal drip includes: (1)avoiding exposure to the allergen if possible, in some cases where the symptoms are severe and unresponsive to treatment then allergy testing may be considered to identify the specific allergen (2) the use of nasal sprays-  your son may want to try using a nasal spray such as nasonex, flonase, beconase (3) you can use the over the counter claritan to help with the symptoms (4) you can also try a mucus thinning medication such as mucinex (5) if there is any nasal congestion, a decongestant can be added If your son uses these allergic remedies and still does not have a response, then you should consider revisiting your doctor I hope this helps </s>