BACKGROUND:Bupivacaine extended-release liposome injection is a novel formulation of bupivacaine designed to achieve long-acting postoperative analgesia. OBJECTIVE:The aim of this study was to compare the magnitude and duration of postoperative analgesia from a single dose of bupivacaine extended-release injection with placebo administered intraoperatively in patients undergoing hemorrhoidectomy. DESIGN:This evaluation was a multicenter, randomized, double-blind, parallel-group, placebo-controlled phase 3 study. SETTINGS:Data were obtained from 13 centers in the Republic of Georgia, Poland, and Serbia. PATIENTS:Included in this study were patients aged 18 to 86 years undergoing excisional hemorrhoidectomy. INTERVENTIONS:All patients received either a single dose of bupivacaine extended-release 300 mg or placebo administered intraoperatively via wound infiltration. MAIN OUTCOME MEASURE:The cumulative pain score was assessed by measurement of the area under the curve of pain intensity through 72 hours after study drug administration. RESULTS:One hundred eighty-nine patients were randomly assigned and treated; 186 completed the study. Pain intensity scores were significantly lower in the bupivacaine extended-release group in comparison with the group receiving placebo (141.8 vs 202.5, P < .0001). More patients in the bupivacaine extended-release group remained opioid free from 12 hours (59%) to 72 hours (28%) after surgery compared with patients receiving placebo (14% and 10%; P < .0008 through 72 h). The mean total amount of opioids consumed through 72 hours was 22.3 mg and 29.1 mg in the bupivacaine extended-release and placebo groups (P ≤ .0006). The median time to first opioid use was 14.3 hours in the bupivacaine extended-release group vs 1.2 hours in the placebo group (P < .0001). A greater proportion of patients in the bupivacaine extended-release group were satisfied with their postsurgical analgesia (95% vs 73%, P = .0007) than in the placebo group. CONCLUSIONS:Bupivacaine extended-release demonstrated a statistically significant reduction in pain through 72 hours, decreased opioid requirements, delayed time to first opioid use, and improved patient satisfaction compared with placebo after hemorrhoidectomy.