Nasal spray oil are also available. There is however no trial-verified evidence that they have a measurable effect on symptoms. Decongestant nasal sprays are available over-the-counter in many countries. They work to very quickly open up nasal passages by constricting blood vessels in the lining of the nose. Prolonged use of these types of sprays can damage the delicate mucous membranes in the nose. This causes increased inflammation, an effect known as rhinitis medicamentosa or the rebound effect. Decongestant nasal sprays are advised for short-term use only, preferably 5 to 7 days at maximum. Some doctors advise to use them 3 days
Nasal administration transfer of drugs is achievable but the possibility of olfactory delivery of therapeutically relevant doses to humans remains to be demonstrated. Nasal administration Nasal administration is a route of administration in which drugs are insufflated through the nose. It can be a form of either topical administration or systemic administration, as the drugs thus locally delivered can go on to have either purely local or systemic effects. Nasal sprays are locally acting drugs such as decongestants for cold and allergy treatment, whose systemic effects are usually minimal. Examples of systemically active drugs available as nasal sprays are migraine drugs, nicotine