What agent is added to local anesthetics to reduce absorption into the bloodstream?

The addition of a vasoconstrictor to local anesthetics serves to reduce absorption into the bloodstream. When a vasoconstrictor is included, it causes the blood vessels in the area to constrict, leading to a decrease in blood flow. This localized restriction of blood flow helps to keep the anesthetic concentrated at the site of injection, prolonging its effect and minimizing systemic absorption.

By reducing the rate at which the anesthetic enters the bloodstream, the overall effectiveness can be increased while also decreasing the potential for systemic side effects, such as toxicity or complications associated with higher levels of the anesthetic circulating in the body. This not only improves patient outcomes but also enhances the safety of administering local anesthesia.

In contrast, vasodilators would increase blood flow, potentially leading to quicker absorption and a shorter duration of pain relief. Anesthetic agents are the primary substances used for pain management, while analgesics are specifically meant for pain relief but do not serve the same function in this context.