A phase 3, randomized, placebo-controlled trial of DepoFoam® bupivacaine (extended-release bupivacaine local analgesic) in bunionectomy

Pain management strategies in hand surgery

Modern anesthetic agents have allowed for the rapid expansion of ambulatory surgery, particularly in hand surgery. The choice between general anesthesia, peripheral regional blocks, regional intravenous anesthesia (Bier block), local block with sedation, and the recently popularized wide-awake hand surgery depends on several variables, including the type and duration of the procedure and patient characteristics, coexisting conditions, location, and expected length of the procedure. This article discusses the various perioperative and postoperative analgesic options to optimize the hand surgical patients' experience.

Unanticipated transient sciatic nerve deficits from intra-wound liposomal bupivacaine injection during total hip arthroplasty

Liposomal bupivacaine (Exparel^®) is a novel formulation of local anesthetic used to provide extended postoperative analgesia as part of a multimodal pain control regimen in patients undergoing total joint arthroplasty. In the three total hip arthroplasty cases described, all patients exhibited a transient loss of neurologic function in the sciatic nerve distribution of the operated extremity lasting between 24 and 72 h during the immediate postoperative period. Due to the nature and duration of the deficits, it was concluded that they likely occurred as a result of unintended injection of the medication in close proximity to the sciatic nerve. To the best of our knowledge, these events have yet to be reported in the current literature. We recommend orthopaedic surgeons pay special attention during infiltration of the medication at the surgical site to avoid postoperative neurological deficits.

Liposomal bupivacaine in forefoot surgery

BACKGROUND

Liposomal bupivacaine is increasingly being utilized in attempts to provide prolonged local analgesia in the immediate postoperative period. The purpose of this study was to quantify the reduction in opioid consumption as well as postoperative pain scores in the postoperative period when liposomal bupivacaine is used at the conclusion of forefoot surgery.

METHODS

This was a prospective therapeutic cohort study with 20 patients receiving liposomal bupivacaine at the conclusion of their forefoot procedure in addition to our routine multimodal analgesic protocol and 20 patients as the control without the addition of liposomal bupivacaine. Pain scores, number of narcotic pills consumed on postoperative days 1 through 4, need for refill, time to first refill and wound complications were evaluated.

RESULTS

Mean number of narcotic pills consumed on postoperative day 1 (1.4 vs 3.6, P = .002) and day 2 (1.8 vs 3.6, P = .021) was significantly lower for the liposomal bupivacaine group than the control group. Daily pain scores were lower for those patients who received liposomal bupivacaine on postoperative days 1 through 4, although this was not statistically significant. Fewer patients required medication refills in the liposomal bupivacaine group compared to the control group, however this was not statistically significant (3 vs 7, P = .273). There was no increase in wound complications in the liposomal bupivacaine group when compared to the control (1 vs 4).

CONCLUSION

Liposomal bupivacaine appears to be a useful adjunct in the treatment of postoperative pain when used as a part of a multimodal analgesic regimen in patients undergoing forefoot surgery.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

The use of exparel (liposomal bupivacaine) to manage postoperative pain in unilateral total knee arthroplasty patients

Efforts continue to improve pain after total knee arthroplasty (TKA) in order to allow for accelerated rehabilitation. The purpose of this study was to evaluate pain control after TKA. A randomized prospective study of 80 consecutive patients was performed comparing Exparel versus femoral nerve block (FNB). Inpatient pain control was the primary outcome. Secondary outcome measures included ROM (extension and flexion), nausea and vomiting, narcotic consumption, ambulation distance, and length of stay (LOS). There were no statistically significant differences between the groups with regard to pain, nausea and vomiting, and narcotic consumption. The FNB group had greater flexion but the Exparel group had improved early ambulation and decreased LOS. Exparel provided similar pain relief to a FNB after TKA without compromising early rehabilitation.

In vivo study of an extended release bupivacaine formulation following site-directed nerve injection

Site-directed administration of local anesthetic agents incorporated into a slow controlled-release injectable implant prolongs the analgesic effect. However, there are potential neuro- and myotoxic consequences. We evaluated a local anesthetic agent (bupivacaine) loaded into a slow-release biodegradable polymer based on castor oil and poly(lactic acid). The formulation was applied directly to the sciatic nerve area in female imprinting control region mice along with appropriate controls. Local nerve and muscle and systemic toxicity were evaluated over a 3-month period following injection of 0.05, 0.1, and 0.125 mL of the 15% bupivacaine–polymer formulation. Histological samples were prepared and examined; no signs of severe inflammation were observed. Histological inflammation signs were more prominent in both nerves and muscles following application of the largest volumes of the polymer formulation (0.1 and 0.125 mL). Following application of 0.1 mL, 15% bupivacaine–polymer formulation, maximal changes were seen in nerve samples two days and two weeks after injection, with complete resolution one month following injection. Neither blank polymer nor plain bupivacaine 0.5% caused any histological changes. Local nerve and muscle toxicity were affected by duration the of exposure and dose of the local anesthetic agent. However, there were clear indications of time-related healing process 3 months after injection.

Bupivacaine liposomal versus bupivacaine: comparative review

Bupivacaine liposomal injection was recently approved by the US Food and Drug Administration (FDA) as a local anesthetic for use in management of postsurgical pain in adults. When compared to placebo, bupivacaine liposomal decreases postoperative pain and opioid use. This review examines the efficacy of bupivacaine liposomal when compared to conventional bupivacaine ± epinephrine using published and unpublished data provided to the FDA by the manufacturer.

Pain Management for Elective Foot and Ankle Surgery: A Systematic Review of Randomized Controlled Trials

Pain after foot and ankle surgery can significantly affect the postoperative outcomes. We performed a systematic review of randomized controlled trials assessing postoperative pain after foot and ankle surgery, because the surgery will lead to moderate-to-severe postoperative pain, but the optimal pain therapy has been controversial. A systematic review of randomized controlled trials in English reporting on pain after foot and ankle surgery in adults published from January 1946 to February 2013 was performed. The primary outcome measure was the postoperative pain scores. The secondary outcome measures included supplemental analgesic requirements and other recovery outcomes. With 953 studies identified, 45 met the inclusion criteria. The approaches improving pain relief (reduced pain scores or opioid requirements) included peripheral nerve blocks, wound infiltration, intravenous dexamethasone, acetaminophen, nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 selective inhibitors, and opioids. Wound instillation, intra-articular injection, and intravenous regional analgesia had variable analgesia. The lack of homogeneous study design precluded quantitative analyses. Optimal pain management strategies included locoregional analgesic techniques plus acetaminophen and nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 selective inhibitors, with opioids used for "rescue," and 1 intraoperative dose of parenteral dexamethasone. Popliteal sciatic nerve blocks would be appropriate when expecting severe postoperative pain (extensive surgical procedure), and ankle blocks and surgical incision infiltration would be appropriate when expecting moderate postoperative pain (less extensive and minimally invasive surgical procedures). Additional studies are needed to assess multimodal analgesia techniques.

Safety of liposome extended-release bupivacaine for postoperative pain control

BACKGROUND

Ideal postoperative pain management requires a multidisciplinary approach in combination with a variety of dosage regimens. Approximately 21-30% of patients experience moderate to severe pain in the postoperative period, which may have a significant impact on recovery rate, standard of living, psychological health, and postoperative complications.

OBJECTIVE

Analysis of the incidence and characterization of reported adverse effects with DepoFoam bupivacaine compared to conventional bupivacaine or placebo.

METHODS

A systematic review of prospective studies on the use of DepoFoam versus bupivacaine or placebo was performed in order to answer the clinically relevant question: is DepoFoam a safer formulation in place of bupivacaine single injection or continuous local infusion techniques for postoperative pain management? Inclusion criteria required randomized, controlled, double-blind trials in patients 18 years old or older, single dose used for postoperative pain control, and a primary procedure performed.

RESULTS

Six studies fitted the inclusion criteria for analysis, DepoFoam bupivacaine used in therapeutic doses was well-tolerated, had a higher safety margin, and showed a favorable safety profile compared to bupivacaine and control groups.

CONCLUSION

Extended drug delivery system DepoFoam bupivacaine is a promising drug formulation that may significantly improve postoperative care and pain control in surgical patients.

Evaluation of DepoFoam(®) bupivacaine for the treatment of postsurgical pain

SUMMARY An extended-release, multivesicular liposome-encapsulated form of the local anesthetic bupivacaine, DepoFoam(®) bupivacaine (proposed proprietary name EXPAREL™), is in development for use as part of a multimodal regimen for the treatment of postsurgical pain. Placebo- and active-controlled clinical trials in patients who have undergone either orthopedic or soft-tissue procedures indicate that a single local administration into the surgical site results in analgesic activity for up to 3-4 days and decreases the use of opioid rescue medication. The safety profile of DepoFoam bupivacaine appears to be similar to that of bupivacaine HCl, and adverse events are dose-related.

Liposomal bupivacaine and clinical outcomes

In the multimodal approach to the management of postoperative pain, local infiltration and regional blocks have been increasingly utilized for pain control. One of the limitations of local anesthetics in the postoperative setting is its relatively short duration of action. Multivesicular liposomes containing bupivacaine have been increasingly utilized for their increased duration of action. Compared with bupivacaine HCl, local infiltration of liposomal bupivacaine has shown to have an increase in duration of action and causes delay in peak plasma concentration. In this article, we attempt to review the clinical literature surrounding liposomal bupivacaine and its evolving role in perioperative analgesia. This new bupivacaine formation may have promising implications in postoperative pain control, resulting in increased patient satisfaction and a decrease in both hospital stay and opioid-induced adverse events (AEs). Although more studies are needed, the preliminary clinical trials suggest that liposomal bupivacaine has predictable pharmacokinetics, a similar side effect profile compared with bupivacaine HCl, and is effective in providing increased postoperative pain control.

Multivesicular liposomal bupivacaine at the sciatic nerve

Clinical translation of sustained release formulations for local anesthetics has been limited by adverse tissue reaction. Exparel™ (DepoFoam bupivacaine) is a new liposomal local anesthetic formulation whose biocompatibility near nerve tissue is not well characterized. Exparel™ injection caused sciatic nerve blockade in rats lasting 240 min compared to 120 min for 0.5% (w/v) bupivacaine HCl and 210 min for 1.31% (w/v) bupivacaine HCl (same bupivacaine content as Exparel™). On histologic sections four days after injection, median inflammation scores in the Exparel™ group (2.5 of 4) were slightly higher than in groups treated with bupivacaine solutions (score 2). Myotoxicity scores in the Exparel™ group (2.5 of 6) were similar to in the 0.5% (w/v) bupivacaine HCl group (3), but significantly less than in the 1.31% (w/v) bupivacaine HCl group (5). After two weeks, inflammation from Exparel™ (score 2 of 6) was greater than from 0.5% (w/v) bupivacaine HCl (1) and similar to that from 1.31% (w/v) bupivacaine HCl (1). Myotoxicity in all three groups was not statistically significantly different. No neurotoxicity was detected in any group. Tissue reaction to Exparel™ was similar to that of 0.5% (w/v) bupivacaine HCl. Surveillance for local tissue injury will be important during future clinical evaluation.

The safety of liposome bupivacaine, a novel local analgesic formulation

OBJECTIVE

Pooled safety data from 10 randomized, double-blind studies of liposome bupivacaine, a novel local analgesic formulation, were examined.

METHODS

Eight hundred twenty-three patients received liposome bupivacaine (dose, 66 to 532 mg) given locally at the surgical site in 5 different settings (hemorrhoidectomy, bunionectomy, breast augmentation, total knee arthroplasty, and hernia repair); 446 received bupivacaine HCl (dose, 75 to 200 mg) and 190 received placebo. Adverse events (AEs) were monitored for up to 36 days after administration.

RESULTS

Overall, 48% of patients were men and 21% were 65 years and older. Incidence of AEs was 62% for patients receiving liposome bupivacaine, versus 75% and 43% for patients receiving bupivacaine HCl and placebo, respectively. The most common AEs (incidence >10%) in the liposome bupivacaine arms were nausea, constipation, and vomiting. One death was reported in the liposome bupivacaine group and 1 in the bupivacaine HCl group; both deemed unrelated to study drug. Serious AEs were reported in 2.7% of patients receiving liposome bupivacaine, versus 5.4% and 1.1% of those receiving bupivacaine HCl and placebo, respectively. In both the liposome bupivacaine and bupivacaine HCl groups, 6% of patients experienced a cardiac AE; these were primarily tachycardia (4% vs. 5%, respectively) and bradycardia (2% vs. 1%, respectively). Overall incidence of treatment-related cardiac AEs was <1%; all were associated with liposome bupivacaine. All of these events were assessed by investigators as possibly related to study drug; all were mild or moderate in severity, and none required therapeutic intervention.

DISCUSSION

Liposome bupivacaine exhibited acceptable tolerability across 823 patient exposures.

Sustained zero-order release of intact ultra-stable drug-loaded liposomes from an implantable nanochannel delivery system

Metronomic chemotherapy supports the idea that long-term, sustained, constant administration of chemotherapeutics, currently not achievable, could be effective against numerous cancers. Particularly appealing are liposomal formulations, used to solubilize hydrophobic therapeutics and minimize side effects, while extending drug circulation time and enabling passive targeting. As liposome alone cannot survive in circulation beyond 48 h, sustaining their constant plasma level for many days is a challenge. To address this, we develop, as a proof of concept, an implantable nanochannel delivery system and ultra-stable PEGylated lapatinib-loaded liposomes, and we demonstrate the release of intact vesicles for over 18 d. Further, we investigate intravasation kinetics of subcutaneously delivered liposomes and verify their biological activity post nanochannel release on BT474 breast cancer cells. The key innovation of this work is the combination of two nanotechnologies to exploit the synergistic effect of liposomes, demonstrated as passive-targeting vectors and nanofluidics to maintain therapeutic constant plasma levels. In principle, this approach could maximize efficacy of metronomic treatments.

A review of the compatibility of liposome bupivacaine with other drug products and commonly used implant materials

The compatibility of a medication with other drugs and implanted materials is an important factor impacting drug safety and efficacy. The liposomal formulation of the local anesthetic bupivacaine is designed to provide prolonged postsurgical analgesia. Its compatibility with other drugs and materials depends on the compatibility of the drug itself, along with the integrity of liposome and liposomal components. A series of studies was conducted to evaluate the compatibility of liposome bupivacaine with diluents, implanted materials, and other drugs likely to be encountered in the surgical settings in which it is used. Liposome bupivacaine demonstrated compatibility with diluents (normal saline, lactated Ringer's solution) and with implanted materials (silicone, stainless steel, titanium, polypropylene, expanded polytetrafluoro-ethylene), with little or no change in percent of free bupivacaine, packed particle volume, or particle size distribution; liposome bupivacaine exhibited little or no change in the properties of the test materials. Liposome bupivacaine had clinically meaningful interactions with other local anesthetics, including lidocaine, ropivacaine, mepivacaine, or bupivacaine HCl (at liposome bupivacaine to bupivacaine HCl ratios < 2:1), which resulted in substantial displacement and release of free bupivacaine from liposomes. Liposome bupivacaine may be locally administered after ≥ 20 minutes following local administration of lidocaine, ropivacaine, or mepivacaine. Co-administration of liposome bupivacaine and bupivacaine HCl into the same site should be at ratios ≥ 2:1. Interactions between liposome bupivacaine and epinephrine, corticosteroids, antibiotics, non-steroidal anti-inflammatory drugs, tranexamic acid, and opioid analgesics were not clinically meaningful; liposome bupivacaine may be safely co-administered with these agents. No adverse synergistic effects on liposome bupivacaine were observed in evaluations involving multiple medications compared with each drug's individual effects.

Lower-dose diclofenac submicron particle capsules provide early and sustained acute patient pain relief in a phase 3 study

BACKGROUND

Non-steroidal anti-inflammatory drugs are prescribed for the treatment of patients with acute pain but use of such analgesics is associated with dose-dependent adverse events (AEs). Diclofenac submicron particle capsules have been developed using SoluMatrix technology to provide analgesia at lower doses than available solid oral dosing forms. Our study evaluated the analgesic efficacy and safety of lower-dose diclofenac submicron particle capsules in patients with acute pain following elective surgery.

METHODS

A phase 3, multicenter, double-blind study enrolled 428 patients, aged 18 to 65 years, with moderate-to-severe pain following bunionectomy under regional anesthesia. Patients experiencing a pain intensity rating of ≥ 40 mm on a 100-mm Visual Analog Scale were randomized to receive lower-dose diclofenac submicron particle capsules (35 or 18 mg, 3 times daily [TID]), celecoxib (200 mg, twice daily [BID], 400-mg loading dose), or placebo. The primary efficacy parameter was the overall (summed) pain intensity difference measured over 0 to 48 hours (SPID-48). Secondary efficacy parameters included pain intensity difference (PID) at scheduled assessments.

RESULTS

Lower-dose diclofenac submicron particle capsules 35 mg TID (524.05; P < 0.001), 18 mg TID (393.25; P = 0.010), and celecoxib 200 mg BID (390.22; P = 0.011) demonstrated significant pain control compared with placebo (77.10) for the primary efficacy parameter, mean SPID-48. Diclofenac submicron particle capsules 35 mg TID (4.52) provided some pain control (higher mean PID) at 30 minutes following administration, in contrast to celecoxib 200 mg BID (0.80), diclofenac submicron particle capsules 18 mg TID (0.31), and placebo (0.12). Better pain control (PID) was noted across all active treatment groups at 5 hours compared with placebo (P ≤ 0.03), and pain relief was sustained throughout the treatment period. The most frequent non-procedure-related AEs were nausea, headache, dizziness, and vomiting.

CONCLUSION

Lower-dose diclofenac submicron particle capsules provided effective analgesia in this phase 3 clinical study in patients with acute pain and are a potentially promising option for the treatment of patients with acute pain.

Liposomal extended-release bupivacaine for postsurgical analgesia

When physicians consider which analgesia to use postsurgery, the primary goal is to relieve pain with minimal adverse side effects. Bupivacaine, a commonly used analgesic, has been formulated into an aqueous suspension of multivesicular liposomes that provide long-lasting analgesia for up to 72 hours, while avoiding the adverse side effects of opioids. The increased efficacy of liposomal extended-release bupivacaine, compared to bupivacaine hydrochloride, has promoted its usage in a variety of surgeries including hemorrhoidectomy, bunionectomy, inguinal hernia repair, total knee arthroplasty, and augmentation mammoplasty. However, like other bupivacaine formulations, the liposomal extended-release bupivacaine does have some side effects. In this brief review, we provide an update of the current knowledge in the use of bupivacaine for postsurgical analgesia.

Facilitatory effects of perineural dexmedetomidine on neuraxial and peripheral nerve block: a systematic review and meta-analysis

Nerve blocks improve postoperative analgesia, but their benefits may be short-lived. This quantitative review examines whether perineural dexmedetomidine as a local anaesthetic (LA) adjuvant for neuraxial and peripheral nerve blocks can prolong the duration of analgesia compared with LA alone. All randomized controlled trials (RCTs) comparing the effect of dexmedetomidine as an LA adjuvant to LA alone on neuraxial and peripheral nerve blocks were reviewed. Sensory block duration, motor block duration, block onset times, analgesic consumption, time to first analgesic request, and side-effects were analysed.

RESULTS

were combined using random-effects modelling. A total of 516 patients were analysed from nine RCTs. Five trials investigated dexmedetomidine as part of spinal anaesthesia and four as part of a brachial plexus (BP) block. Sensory block duration was prolonged by 150 min [95% confidence interval (CI): 96, 205, P<0.00001] with intrathecal dexmedetomidine. Perineural dexmedetomidine used in BP block may prolong the mean duration of sensory block by 284 min (95% CI: 1, 566, P=0.05), but this difference did not reach statistical significance. Motor block duration and time to first analgesic request were prolonged for both intrathecal and BP block. Dexmedetomidine produced reversible bradycardia in 7% of BP block patients, but no effect on the incidence of hypotension. No patients experienced respiratory depression. Dexmedetomidine is a potential LA adjuvant that can exhibit a facilitatory effect when administered intrathecally as part of spinal anaesthesia or peripherally as part of a BP block. However, there are presently insufficient safety data to support perineural dexmedetomidine use in the clinical setting.

Local toxicity from local anesthetic polymeric microparticles

BACKGROUND

Local tissue injury from sustained-release formulations for local anesthetics can be severe. There is considerable variability in reporting of that injury. We investigated the influence of the intrinsic myotoxicity of the encapsulated local anesthetic (lidocaine, low; bupivacaine, high) on tissue reaction in rats.

METHODS

Cytotoxicity from a range of lidocaine and bupivacaine concentrations was measured in C2C12 myotubes over 6 days. Rats were given sciatic nerve blocks with 4 microparticulate formulations of lidocaine and bupivacaine: 10% (w/w) lidocaine poly(lactic-co-glycolic) acid (PLGA), 10% (w/w) bupivacaine PLGA, 50% (w/w) lidocaine PLGA, and 50% (w/w) bupivacaine PLGA. Effectiveness of nerve blockade was assessed by a modified hotplate test and weightbearing measurements. Myotoxicity was scored in histologic sections of injection sites. Bupivacaine and lidocaine release kinetics from the particles were measured.

RESULTS

Median sensory blockade duration for 50% (w/w) lidocaine was 255 (90-540) minutes versus 840 (277-1215) minutes for 50% (w/w) bupivacaine (P = 0.056). All microparticulate formulations resulted in myotoxicity. The choice of local anesthetic did not influence the severity of myotoxicity. Median myotoxicity scores for 50% (w/w) lidocaine compared with 50% (w/w) bupivacaine at 4 days were 3.4 (2.1-4.2) vs 3.3 (2.9-3.5) (P = 0.44) and at 14 days 1.9 (1.8-2.4) vs 1.7 (1.3-1.9) (P = 0.23), respectively.

CONCLUSIONS

Lidocaine and bupivacaine PLGA microspheres resulted in similar degrees of myotoxicity, irrespective of drug loading. Intrinsic myotoxicity did not predict tissue injury from sustained release of these anesthetics. Caution is warranted in the use of such devices near muscle and nerve.

Bupivacaine liposome injectable suspension compared with bupivacaine HCl for the reduction of opioid burden in the postsurgical setting

OBJECTIVE

Assess comparative efficacy of liposome bupivacaine administered at doses ≤266 mg and bupivacaine HCl administered at doses ≤200 mg for postsurgical analgesia.

RESEARCH DESIGN AND METHODS

Analysis of pooled efficacy and safety data from nine double-blind, placebo or active (bupivacaine HCl) controlled multimodal analgesia studies using a single dose of liposome bupivacaine or comparator, given via administration into the surgical site before end of surgery (i.e., inguinal hernia repair, total knee arthroplasty, hemorrhoidectomy, breast augmentation, or bunionectomy). Data from study arms that received liposome bupivacaine doses ≤266 mg were included.

CLINICAL TRIAL REGISTRATION

Pooled data analysis includes nine studies: Study 1 - NCT01203644; Study 2 - NCT00485433; Study 3 - NCT00485693; Study 4 - NCT00529126; Study 5 - NCT00745290; Study 6 - NCT00744848; Study 7 - NCT00813111; Study 8 - NCT00890721; Study 9 - NCT00890682.

MAIN OUTCOME MEASURES

Outcome measures included area under the curve (AUC) of pain intensity scores assessed by numeric rating scale (NRS) through 72 h postsurgery, time to first use of rescue opioid medications, total amount (mg) of opioid medications used, and occurrence of opioid-related adverse events (ORAEs). Incidence of overall AEs was also assessed.

RESULTS

Mean cumulative pain score (AUC of NRS through 72 h) was significantly lower with liposome bupivacaine (283) compared with bupivacaine HCl (329, p = 0.039). Median time from administration of study drug to first use of opioid rescue medication was significantly longer for liposome bupivacaine (10 h vs 3 h, p < 0.0001). Liposome bupivacaine was associated with a significant reduction in opioid use (12 mg vs 19 mg; p < 0.0001) and incidence of ORAEs (20% vs 36%; p < 0.0001), compared with bupivacaine HCl.

CONCLUSIONS

In this pooled analysis from nine studies representing five different surgical procedures, liposome bupivacaine administered at doses ≤266 mg in a multimodal setting was associated with statistically significant and clinically meaningful lower cumulative pain score at 72 h, delayed and less consumption of opioids, and fewer ORAEs than bupivacaine HCl.

Liposomal bupivacaine: an innovative nonopioid local analgesic for the management of postsurgical pain

Local anesthetics are a cornerstone of multimodal pain control strategies in the surgical setting as they have a long history of use and an established safety profile. Although effective, their duration of action is relatively short, which usually leads to the use of other agents, such as opioids, for effective postsurgical pain control in most patients. A medical need exists to extend the duration of analgesia with local anesthetics to help reduce the reliance on opioids in the postsurgical setting. Liposomal bupivacaine uses a product delivery platform to release bupivacaine slowly over 96 hours after infiltration at the surgical site. Liposomal bupivacaine was compared with placebo in two pivotal, multicenter, randomized, double-blind, parallel-group trials in 189 adults undergoing soft-tissue surgery (hemorrhoidectomy) and 193 adults undergoing orthopedic surgery (bunionectomy). Among patients undergoing hemorrhoidectomy, liposomal bupivacaine significantly reduced cumulative pain scores for up to 72 hours (primary end point) as measured by the area under the curve of pain scores on the numeric rating scale (p<0.0001), reduced overall opioid consumption (p ≤ 0.0006), increased the proportion of patients who did not receive opioids (p<0.0008), delayed time to first opioid by more than 13 hours (p<0.0001), and was associated with significantly higher rates of patient satisfaction (p=0.0007) compared with placebo. Similarly, in patients undergoing bunionectomy, liposomal bupivacaine significantly reduced total consumption of rescue opioids (p=0.0077) and cumulative pain scores as measured by the area under the curve of pain scores on the numeric rating scale (p=0.0005) during the first 24 postsurgical hours (primary end point) relative to placebo. Furthermore, liposomal bupivacaine also significantly delayed the time to first use of opioid rescue (p<0.0001) and increased the proportion of patients requiring no rescue opioid treatment (p ≤ 0.0404) compared with placebo. The most common adverse events with liposomal bupivacaine were nausea, vomiting, and constipation. No adverse effects on the QTc interval or cardiac safety signal have been detected in the clinical trial development program (823 patients) when liposomal bupivacaine was infiltrated into the surgical site. The beneficial effects of liposomal bupivacaine on postsurgical pain management and opioid use, significantly reducing both, are likely to translate into improved clinical and economic outcomes.

Liposomal bupivacaine: a review of a new bupivacaine formulation

Many attempts have been made to increase the duration of local anesthetic action. One avenue of investigation has focused on encapsulating local anesthetics within carrier molecules to increase their residence time at the site of action. This article aims to review the literature surrounding the recently approved formulation of bupivacaine, which consists of bupivacaine loaded in multivesicular liposomes. This preparation increases the duration of local anesthetic action by slow release from the liposome and delays the peak plasma concentration when compared to plain bupivacaine administration. Liposomal bupivacaine has been approved by the US Food and Drug Administration for local infiltration for pain relief after bunionectomy and hemorrhoidectomy. Studies have shown it to be an effective tool for postoperative pain relief with opioid sparing effects and it has also been found to have an acceptable adverse effect profile. Its kinetics are favorable even in patients with moderate hepatic impairment, and it has been found not to delay wound healing after orthopedic surgery. More studies are needed to establish its safety and efficacy for use via intrathecal, epidural, or perineural routes. In conclusion, liposomal bupivacaine is effective for treating postoperative pain when used via local infiltration when compared to placebo with a prolonged duration of action, predictable kinetics, and an acceptable side effect profile. However, more adequately powered trials are needed to establish its superiority over plain bupivacaine.

Efficacy profile of liposome bupivacaine, a novel formulation of bupivacaine for postsurgical analgesia

Background

Liposome bupivacaine is a novel formulation of the local anesthetic bupivacaine, designed to provide prolonged postsurgical analgesia. This analysis examined pooled efficacy data as reflected in cumulative pain scores from 10 randomized, double-blind liposome bupivacaine clinical studies in which the study drug was administered via local wound infiltration.

Methods

A total of 823 patients were exposed to liposome bupivacaine in 10 local wound infiltration studies at doses ranging from 66 mg to 532 mg in five surgical settings; 446 patients received bupivacaine HCl (dose: 75–200 mg) and 190 received placebo. Efficacy measures were assessed through 72 hours after surgery.

Results

Overall, 45% of patients were male and 19% were ≥65 years of age. In the analysis of cumulative pain intensity scores through 72 hours, liposome bupivacaine was associated with lower pain scores than the comparator in 16 of 19 treatment arms assessed, achieving statistically significant differences compared with bupivacaine HCl (P < 0.05) in five of 17 treatment arms. These results were supported by results of other efficacy measures, including time to first use of opioid rescue medication, proportion of patients avoiding opioid rescue medication, total postsurgical consumption of opioid rescue medication, and patient/care provider satisfaction with postoperative analgesia. Local infiltration of liposome bupivacaine resulted in significant systemic plasma levels of bupivacaine, which could persist for 96 hours; systemic plasma levels of bupivacaine following administration of liposome bupivacaine were not correlated with local efficacy. Liposome bupivacaine and bupivacaine HCl were generally well tolerated.

Conclusion

Based on this integrated analysis of multiple efficacy measures, liposome bupivacaine appears to be a potentially useful therapeutic option for prolonged reduction of postsurgical pain in soft tissue and orthopedic surgeries.

Evaluating therapeutic benefit in postsurgical analgesia requires global assessment: an example from liposome bupivacaine in hemorrhoidectomy

BACKGROUND AND OBJECTIVE

Interpreting analgesic efficacy based solely on measures of pain intensity can be misleading. Here, we use data from an adult hemorrhoidectomy study to demonstrate the importance of evaluating pain intensity scores with other outcome measures in interpreting analgesic study results.

METHODOLOGY

We looked for coordinated outcome measures including pain intensity at rest using a numeric rating scale (NRS), postsurgical consumption of rescue medication, subject-reported results from the Brief Pain Inventory, subject satisfaction with postsurgical analgesia, and adverse events.

RESULTS

The analgesic efficacy of liposome bupivacaine was reflected in a significant reduction in pain intensity scores at each timed assessment during the first 12 to 24 hours after surgery (mean NRS at 12 hours: liposome bupivacaine, 2.2; placebo, 2.9; P = 0.04), and less consumption of opioid rescue medications thereafter through 72 hours postsurgery (mean total amount of opioids consumed: liposome bupivacaine, 10 mg; placebo, 18 mg; P = 0.0006). These observations are supported by results of other outcome measures, including time to first use of opioid rescue medication, pain-related interference of subject functionality, and subject satisfaction with postsurgical analgesia.

CONCLUSION

Liposome bupivacaine produced superior analgesia when compared with placebo at early postoperative time points, but appropriate use of rescue medication diminished this effect after 12 hours. However, based on our assessment of multiple outcome measures used in the study, it appears that the therapeutic benefit associated with the tested analgesic lasted throughout the 72-hour study period.

A two-year observational study assessing the safety of DepoFoam bupivacaine after augmentation mammaplasty

BACKGROUND

Two-year safety outcomes in patients who received DepoFoam bupivacaine during two prior breast augmentation studies were evaluated.

OBJECTIVES

The authors assess the clinical sequelae observed during follow-up examination with respect to the integrity of the breast implants.

METHODS

In Study 1, patients received bupivacaine HCl (75 mg) in one breast pocket and DepoFoam bupivacaine (133 or 266 mg) in the other. In Study 2, patients received either bupivacaine HCl (200 mg) or DepoFoam bupivacaine (532 mg), divided equally into each breast pocket. Investigators and patients remained blinded to the treatment administered. Patients completed a questionnaire regarding breast pain, tenderness, tingling, numbness, burning, changes in sensation, and any relevant life events potentially affecting the implants. Patients were also assessed for postoperative healing and implant integrity.

RESULTS

Ninety-four women were evaluated. Most patients in all groups had no change in breast size or shape and no changes in the skin or nipple. There were no reports of palpable hard knots or swelling. There was one report of irritation/implant leakage (in a patient who received bupivacaine HCl [75 mg] in the relevant breast). Most patients reported no breast pain, tenderness, tingling, numbness, burning, other changes in sensation, chest wall surgery or trauma, or life events affecting the implant.

CONCLUSIONS

At a two-year follow-up assessment, DepoFoam bupivacaine was not associated with any complications that would compromise the integrity of the breast implants. There was no indication of an association between DepoFoam bupivacaine or bupivacaine HCl and changes in sensation or other abnormal findings in these patients.

LEVEL OF EVIDENCE

2.