Ngh?t m?i v? ?êm là tình tr?ng r?t ph? bi?n ?nh h??ng tr?c ti?p ??n ch?t l??ng gi?c ng?. Lâu…· Should you be allergic (hypersensitive) to xylometazoline or any of the opposite ingredients of the drugs,This known as rebound congestion, and it can lead to cycles of even further problems with congestion. Using the spray/drops for just a few tim