Three Newly Approved Analgesics: An Update

Abstract

Abstract Since 2008, three new analgesic entities, tapentadol immediate release (Nucynta) diclofenac potassium soft gelatin capsules (Zipsor), and bupivacaine liposome injectable suspension (EXPAREL) were granted US Food and Drug Administration (FDA) approval to treat acute pain. Tapentadol immediate-release is a both a mu-opioid agonist and a norepinephrine reuptake inhibitor, and is indicated for the treatment of moderate to severe pain. Diclofenac potassium soft gelatin capsules are a novel formulation of diclofenac potassium, which is a nonsteroidal anti-inflammatory drug (NSAID), and its putative mechanism of action is through inhibition of cyclooxygenase enzymes. This novel formulation of diclofenac allows for improved absorption at lower doses. Liposomal bupivacaine is a new formulation of bupivacaine intended for single-dose infiltration at the surgical site for postoperative analgesia. Bupivacaine is slowly released from this liposomal vehicle and can provide prolonged analgesia at the surgical site. By utilizing NSAIDs and local anesthetics to decrease the transmission of afferent pain signals, less opioid analgesics are needed to achieve analgesia. Since drug-related adverse events are frequently dose related, lower doses from different drug classes may be employed to reduce the incidence of adverse effects, while producing synergistic analgesia as part of a multimodal analgesic approach to acute pain.