What adrenergic agonist is commonly found in over-the-counter nasal sprays for congestion?

Oxymetazoline is an adrenergic agonist that is specifically used in over-the-counter nasal sprays to relieve nasal congestion. It works primarily as a selective agonist of the alpha-1 adrenergic receptors, leading to vasoconstriction of blood vessels in the nasal mucosa. This vasoconstriction reduces blood flow to the area, resulting in decreased swelling and congestion. The quick onset and localized action make it effective for short-term relief of nasal congestion associated with colds, allergies, and sinusitis.

In the context of other options, clonidine is primarily used as an antihypertensive medication and acts on central alpha-2 adrenergic receptors rather than being suitable for nasal applications. Albuterol is a beta-2 adrenergic agonist primarily used for treating bronchospasm in conditions like asthma and is not designed for nasal use. Formoterol is another beta-agonist used for similar purposes as albuterol but is extended-release and not specifically for nasal congestion. Thus, oxymetazoline stands out as the correct choice for this particular application in over-the-counter products.