<prompt> The most likely complication of prolonged use of nasal decongestant drops isAtrophic rhinitisNaso-pharyngeal moniliasisHyperophy of nasal mucosaBlockage of eustachian tubes  <response>: NASAL DECONGESTANTS These are a agonists which on topical application as dilute solution 0.05-0.1 produce local vasoconstriction. The imidazoline compounds-- naphazoline, xylometazoline and oxymetazoline are relatively selective a2 agonist like clonidine. They have a longer duration of action 12 hours than ephedrine. side effects:- They may cause initial stinging sensation Especially naphazoline. Regular use of these agents for long periods should be avoided because mucosal ciliary function is impaired: atrophic rhinitis and anosmia can occur due to persistent vasoconstriction. They can be absorbed from the nose and produce systemic effects, mainly CNS depression and rise in BP. cautious use:- These drugs should be used cautiously in hypeensives and in those receiving MAO inhibitors. Ref:- kd tripathi; pg num:-136 