Final answer:
Phenylephrine is an alpha-1 agonist used in surgery to counteract hypotension and as a decongestant in patients with congestion.
Step-by-step explanation:
The alpha-1 agonist commonly administered to patients experiencing surgical-induced hypotension as a vasoconstrictive agent is phenylephrine. This sympathomimetic drug is also a component of decongestants used for relieving congestion. Phenylephrine’s primary mechanism of action involves stimulating α₁-adrenergic receptors, which can cause blood vessels to constrict, thereby raising blood pressure. During surgery, it is often used as an intravenous infusion to counteract the drop in blood pressure that can occur from anesthesia. Additionally, it can provide relief from congestion by dilating the bronchioles in the lungs and helping to clear mucus from the lower respiratory tract.