A decongestant, or nasal decongestant, is a type of pharmaceutical drug that is used to relieve nasal congestion in the upper respiratory tract. The active ingredient in most decongestants is either pseudoephedrine or phenylephrine (the latter of which has disputed effectiveness). Intranasal corticosteroids can also be used as decongestants and antihistamines can be used to alleviate runny nose, nasal itch, and sneezing.[1]
Topical decongestants on topical application as dilute solution (0.05–0.1%) produce local vasoconstriction.
Regular use of decongestants for long periods should be avoided because mucosal ciliary function is impaired: atrophic rhinitis and anosmia (loss of the sense of smell) can occur due to persistent vasoconstriction.
Decongestants can be absorbed from the nose via an inhaler and produce systemic effects, mainly central nervous system stimulation and rise in blood pressure. These drugs should be used cautiously in hypertensives and in those receiving monoamine oxidase inhibitors (MAOIs), as they can cause hypertensive crisis.
Expectorants such as guaifenesin are a related type of drug which help to clear mucus.