Epinephrine
Epinephrine
Epinephrine is the most common additive used in local anesthesia.6 It counters the local anesthetic’s tendency to induce vascular smooth muscle relaxation, which can promote bleeding.5 Vasoconstrictive effects occur quickly, with full effects taking 7 to 15 minutes.5,14 Epinephrine limits anesthetic diffusion and helps to minimize the absorption of anesthetic into the systemic circulation. It also allows less anesthesia to be used to complete the numbing process. A liability for epinephrine use is the potential for delayed bleeding once its effects wear off. Concerns for postoperative hematoma development14 should be addressed with the patient prior to surgery. Epinephrine is labeled as a Category C drug.