Final answer:
Mixed acting adrenergic agonists such as ephedrine work by directly stimulating adrenergic receptors and increasing endogenous catecholamine levels, resulting in enhanced sympathetic activity.
Step-by-step explanation:
An example of a mixed acting adrenergic agonist is ephedrine, which activates both α and β adrenergic receptors and enhances the release of norepinephrine. Ephedrine elevates blood pressure, increases heart rate, and dilates bronchioles, emulating the body's fight-or-flight response. Mixed acting adrenergic agonists like ephedrine are often used in medical settings to manage conditions like hypotension and asthma, providing relief by stimulating sympathetic activity.
Another example includes pseudoephedrine, commonly found in decongestants, which also exhibits both direct and indirect adrenergic activity.
These drugs function as sympathomimetics by either binding to adrenergic receptors or increasing the endogenous catecholamines like norepinephrine and epinephrine, thus causing a sympathetic response.