Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.

The safety of ZYNRELEF has been evaluated in a total of 1627 patients undergoing various surgical procedures across 14 clinical studies including 7 randomized, double-blind, bupivacaine- and placebo-controlled and saline placebo-controlled studies designed to investigate ZYNRELEF to reduce postoperative pain for 72 hours and the need for opioid analgesics, of whom 1183 received ZYNRELEF by instillation. Patients treated with ZYNRELEF ranged in age from 18 to 85 years (median age 51 years), with 53.0% female, 82.1% White, 13.7% African-American, and 4.3% all other races.

Common Adverse Reactions

The safety of ZYNRELEF has been evaluated in 1064 patients who received ZYNRELEF in single doses up to 400 mg/12 mg via instillation into the surgical site, including 533 patients undergoing a soft tissue surgical procedure (herniorrhaphy, abdominoplasty, augmentation mammoplasty, or Cesarean section) and 531 patients undergoing an orthopedic surgical procedure (bunionectomy, total knee arthroplasty, total shoulder arthroplasty, or lumbar spinal surgery). The most common adverse reactions (incidence greater than or equal to 5% and higher than placebo) following ZYNRELEF administration among patients undergoing soft tissue procedures was vomiting and among patients undergoing orthopedic procedures were constipation and headache.

The safety of ZYNRELEF as part of a scheduled, non-opioid multimodal analgesic regimen including 1 or more other NSAIDs has been evaluated in a total of 473 patients undergoing soft tissue procedures or orthopedic procedures. NSAIDs included ibuprofen, ketorolac, and celecoxib. In these studies, the most common adverse reactions (incidence of greater than or equal to 2%) potentially associated with NSAIDs were pruritus and postoperative anemia. Rare but clinically serious NSAID-related adverse events, including peptic ulcer hemorrhage, gastritis requiring hospitalization, hematemesis and melena, gastrointestinal hemorrhage, and increased hepatic enzymes, were observed in subjects with predisposing risk factors (i.e., concomitant comorbidities and/or on concomitant medications such as anticoagulant and/or antiplatelet medications) that increased the risk for NSAID-related gastrointestinal toxicity.

Adverse Reactions Reported in Phase 3 and 2b Placebo-controlled Trials

Three randomized, bupivacaine-controlled and saline placebo-controlled studies were conducted in patients undergoing bunionectomy (STUDY 1, Table 1 and Table 2), open inguinal herniorrhaphy (STUDY 2, Table 3), and total knee arthroplasty (STUDY 3, Table 4). The bunionectomy procedures in STUDY 1 were performed under regional anesthesia, a lidocaine Mayo block, and intravenous sedation. The herniorrhaphy procedures in STUDY 2 were performed under general anesthesia. The total knee arthroplasty procedures in STUDY 3 were performed under either general or spinal anesthesia. Patients in STUDY 1 and STUDY 2 were allowed opioid rescue with intravenous (IV) morphine and oral oxycodone, and/or non-opioid rescue with oral acetaminophen. Patients in STUDY 3 were pretreated with oral pregabalin and acetaminophen, and allowed opioid rescue with IV morphine and oral oxycodone postoperatively.

In STUDY 1, bone healing was assessed by X-ray on Days 28 and 42. There was no clinically meaningful difference in bone healing between treatment groups. A total of 4 subjects had delayed bone healing: 1 in the ZYNRELEF group, 1 in the saline placebo group, and 2 in the bupivacaine HCl group.

The incidence of local inflammatory adverse events was higher in the ZYNRELEF group than in either control group (Table 2).