Any sprayers, inhalators, or devices used to deliver the decongestants become reservoirs for bacteria over time, so should be discarded when the medication is no longer needed. If the medicine becomes cloudy or unclear, it, too, should be discarded. Droppers and inhalators should not be shared with other people, and they should not be inserted into the nostril. Nasal decongestants are generally recommended for no more than one to three days because of the risk of nasal irritation and rebound and dependency. Short-acting nasal decongestants may have a rebound effect after only eight hours.
Children appear to metabolize decongestants differently from adults.
Decongestants should not be used at all in infants and small children, who are at particular risk for side effects that depress the central nervous system, which can result in changes in blood pressure, drowsiness, deep sleep, and, rarely, coma. Of some concern is a study indicating that decongestants, particularly those containing pseudoephedrine, may increase the risk for stroke in certain individuals. It is important to note, however, that this is a very rare occurrence. Those at risk are people whose blood vessels are highly susceptible to contraction, including those with migraines and Raynaud's phenomenon, in which people are highly sensitive to cold. Histamine is the chemical released when antibodies overreact to allergens and is the cause of many symptoms of allergic rhinitis.