Clinical efficacy of controlled-release oxycodone 20 mg administered on a 12-h dosing schedule on the management of postoperative pain after breast surgery for cancer

Perioperative Breast Analgesia: a Systematic Review of the Evidence for Perioperative Analgesic Medications

PURPOSE OF REVIEW

Breast surgery is common and may result in significant acute as well as chronic pain. A wide range of pharmacologic interventions is available including opioids, non-steroidal anti-inflammatory drugs (NSAIDs), N-methyl-D-aspartate (NMDA) receptor antagonists, anticonvulsants, and other non-opioids with analgesic properties. We present a review of the evidence for these pharmacologic interventions. A literature search of the MEDLINE database was performed via PubMed with combined terms related to breast surgery, anesthesia, and analgesia. Articles were limited to randomized controlled trial (RCT) design, adult patients undergoing elective surgery on the breast (not including biopsy), and pharmacologic interventions only. Article titles and abstracts were screened, and risk of bias assessments were performed.

RECENT FINDINGS

The search strategy initially captured 7254 articles of which 60 articles met the full inclusion criteria. Articles were organized according to intervention: 6 opioid agonists, 14 NSAIDs and acetaminophen, 4 alpha-2 agonists, 7 NMDA receptor antagonists, 6 local anesthetics, 7 steroids, 15 anticonvulsants (one of which also discussed an NMDA antagonist), 1 antiarrhythmic, and 2 serotonin reuptake inhibitors (one of which also studied an anticonvulsant). A wide variety of medications is effective for perioperative breast analgesia, but results vary by agent and dose. The most efficacious are likely NSAIDs and anticonvulsants. Some agents may also decrease the incidence of chronic postoperative pain, including flurbiprofen, gabapentin, venlafaxine, and memantine. While many individual agents are well studied, optimal combinations of analgesic medications remain unclear.

Postoperative use of slow-release opioids: The impact of the Australian and New Zealand College of Anaesthetists/Faculty of Pain Medicine position statement on clinical practice

Dose titration with immediate-release opioids is currently recommended for acute pain. The Australian and New Zealand College of Anaesthetists and the Faculty of Pain Medicine released a statement in March 2018 supporting their use in the treatment of opioid-naïve patients; however, the impact of this statement on clinical practice is currently unknown. This retrospective cohort study was conducted to compare opioid prescribing patterns before and after the release of the recommendations. Data were collected on 184 patients (2017, n = 78; 2018, n = 106) admitted to the Prince of Wales Hospital in November 2017 and 2018, which consisted of demographic data, opioid prescriptions and discharge opioid information. The main outcome is the number of prescriptions of slow-release opioids in 2017 versus 2018 after the recommendations were published. Confounding factors were accounted for using logistic and multiple regression as appropriate. There was a 29% decrease in slow-release opioid prescriptions during hospitalisation ( n = 31, 40% versus n = 12, 11%; P < 0.001) and 17% decrease at discharge ( n = 20, 26% versus n = 9, 9%; P = 0.02) post-publication. After adjusting for confounders, the odds of slow-release opioids being prescribed postoperatively and at discharge reduced by 86% and 88%, respectively (postoperative period: odds ratio 0.14, P < 0.05; discharge: odds ratio 0.12, P < 0.05). In addition, orthopaedic patients were more likely to receive slow-release opioids, consistent with existing literature. As the use of slow-release opioids has been associated with increased harm and protracted opioid use compared to immediate-release opioids, it is hoped that wider dissemination of these recommendations and a change in prescribing practice can be a step towards overcoming the opioid crisis.

Pain Management in Breast Surgery: Recommendations of a Multidisciplinary Expert Panel-The American Society of Breast Surgeons

Opioid overdose accounted for more than 47,000 deaths in the United States in 2018. The risk of new persistent opioid use following breast cancer surgery is significant, with up to 10% of patients continuing to fill opioid prescriptions one year after surgery. Over prescription of opioids is far too common. A recent study suggested that up to 80% of patients receiving a prescription for opioids post-operatively do not need them (either do not fill the prescription or do not use the medication). In order to address this important issue, The American Society of Breast Surgeons empaneled an inter-disciplinary committee to develop a consensus statement on pain control for patients undergoing breast surgery. Representatives were nominated by the American College of Surgeons, the Society of Surgical Oncology, The American Society of Plastic Surgeons, and The American Society of Anesthesiologists. A broad literature review followed by a more focused review was performed by the inter-disciplinary panel which was comprised of 14 experts in the fields of breast surgery, anesthesiology, plastic surgery, rehabilitation medicine, and addiction medicine. Through a process of multiple revisions, a consensus was developed, resulting in the outline for decreased opioid use in patients undergoing breast surgery presented in this manuscript. The final document was reviewed and approved by the Board of Directors of the American Society of Breast Surgeons.

A review of postoperative analgesia for breast cancer surgery

An online database search with subsequent article review was performed in order to review the various analgesic modalities for breast cancer surgery. Of 514 abstracts, 284 full-length manuscripts were reviewed. The effect of pharmacologic interventions is varied (NSAIDS, opioids, anticonvulsants, ketamine, lidocaine). Likewise, data from high-quality randomized, controlled studies on wound infiltration (including liposome encapsulated) and infusion of local anesthetic are minimal and conflicting. Conversely, abundant evidence demonstrates paravertebral blocks and thoracic epidural infusions provide effective analgesia and minimize opioid requirements, while decreasing opioid-related side effects in the immediate postoperative period. Other techniques with promising – but extremely limited – data include cervical epidural infusion, brachial plexus, interfascial plane and interpleural blocks. In conclusion, procedural interventions involving regional blocks are more conclusively effective than pharmacologic modalities in providing analgesia to patients following surgery for breast cancer.

Long-acting morphine following hip or knee replacement: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Patients undergoing total hip or knee replacement surgery experience unmanaged pain during postoperative physiotherapy sessions. It was theorized that a baseline opioid would improve pain management.

OBJECTIVES

To examine the effectiveness of adding long-acting oral morphine to a routine postoperative regimen for total hip or knee replacement surgery.

METHODS

The present study was a double-blind, randomized, placebo-controlled trial for patients undergoing total hip or knee replacement surgery. All patients received routine postoperative analgesia; in addition, the treatment group received long-acting oral morphine 30 mg orally twice daily for three days, while the control group received placebo capsules. The primary end point was a decrease in pain scores by two points on a 0- to 10-point pain rating scale. Secondary end points included adverse effects, acute confusion, pain-related interferences in function and sleep, length of stay and patient satisfaction.

RESULTS

Two hundred patients were enrolled in the present study (March 2004 to March 2006). Although the groups were large enough to yield statistical significance, most pain scores did not reach the predetermined improvement for clinical significance. Additionally, there was an increase in opioid usage (P<0.0001), vomiting (P=0.0148) and oversedation (P=0.08). There were no statistically significant changes in function or sleep. Improved satisfaction with pain management was minimal (P=0.052).

DISCUSSION

The present study was undertaken to determine the value of adding a long-acting opioid (morphine) to the usual care of patients undergoing total hip or total knee replacement surgery. The results yielded minimally improved pain scores and additional adverse effects (vomiting and oversedation). Published research in which long-acting opioids (oxycodone) were used for similar postoperative procedures did not robustly report improved pain scores. In addition, patients using a long-acting opioid (oxycodone) during the postoperative period reported somnolence, dizziness and confusion. Statistically, the patients in the present study showed higher confusion scores and no improvement for pain-related interferences with activity or walking. The treatment group did report increased satisfaction; however, the significance was weak.

CONCLUSIONS

Thirty milligrams twice per day of long-acting morphine from days 1 to 3 following total hip and total knee replacement surgery provided minimal improvements in pain scores, and more adverse effects in the treatment group. The overall strength of evidence for improved outcomes is minimal and thus not supported.

Liver cancer: effects, safety, and cost-effectiveness of controlled-release oxycodone for pain control after TACE

PURPOSE

To evaluate the analgesic effect, safety, and cost-effectiveness of controlled-release oxycodone (CRO) to control postoperative pain in patients with liver cancer who are undergoing transarterial chemoembolization.

MATERIALS AND METHODS

This randomized, double-blind, placebo-controlled, prospective clinical study received institutional review board approval. After written informed consent was obtained, 210 patients with liver cancer were randomized into three groups of 70 patients. Group 1 received 20 mg of CRO, group 2 received 10 mg of CRO, and group 3 received a placebo at 1 hour before transarterial chemoembolization (T(0)) and 12 (T(12)) and 24 (T(24)) hours after T(0). Pain intensity on a numeric rating scale, percentage of patients with each degree of pain, quality of life, adverse reactions, analgesic costs, and hospital stays were evaluated and compared among the three groups.

RESULTS

Numeric rating scale scores for pain intensity in group 1 and group 2 were significantly lower than those in group 3 at T(0-12) (P < .001); T(12-24) (P < .001); and T(24-48) (P < .001). When group 1 with group 2 were compared, numeric rating scale scores were significantly lower in group 1 than in group 2 during the period of T(0-12) (P < .001) but were not significantly different at T(12-24) (P = .68) and T(24-48) (P = .10). Analgesic cost and hospital stay were significantly lower in treated groups than in the placebo group. No significant difference was observed in quality of life and adverse events between the treated groups and the placebo group.

CONCLUSION

CRO is effective, safe, and cost-effective in the control of postoperative pain after transarterial chemoembolization for patients with inoperable liver cancer.

[New substances and applications for postoperative pain therapy]

The onset of postoperative pain is the result of various pathophysiological mechanisms and depends on the type of surgery performed. Therefore, any adequate postoperative pain treatment requires multimodal and procedure-specific analgesia. In addition to reducing perioperative complications and improving patient comfort, optimal postoperative pain management also represents an important quality characteristic which can influence the patient in their choice of hospital. In the past 1-2 years, known groups of substances have been rediscovered for postoperative pain therapy (e.g., Gabapentin and Pregabalin, i.v. Lidocaine, Ketamine or glucocorticoids), while new substances (coxibe, oral oxycodone+naloxone) and applications have been developed. The present overview article discusses the advantages and disadvantages of these substances and analgesic methods, as well as their specific areas of application.

Postoperative Intravenous Morphine Consumption, Pain Scores, and Side Effects with Perioperative Oral Controlled-Release Oxycodone After Lumbar Discectomy

BACKGROUND

Oral opioid formulations contribute to postoperative analgesia. In this study, we evaluated the perioperative application of oral controlled-release oxycodone to reduce postoperative IV morphine consumption and opioid side effects after lumbar discectomy.

METHODS

Forty patients scheduled for elective lumbar discectomy over 1 or 2 levels were included in this prospective, randomized, double-blind, placebo-controlled study. Every 12 h patients received either 20 mg oral controlled-release oxycodone or placebo, from the evening before surgery until the second postoperative morning. All patients received IV morphine via a morphine patient-controlled analgesia device for postoperative analgesia. Acetaminophen 1 g was administered to all patients every 6 h. Postoperative IV morphine consumption was assessed separately for T(0)-T(24) and T(24)-T(48). Postoperative assessments were conducted every 6 h for the first 48 h after surgery. Postoperative analgesia assessments included pain at rest, during coughing, and with motion, using a visual analog scale. Nausea, vomiting, pruritus, sedation, and bowel function were also assessed every 6 h. Patients rated their satisfaction with postoperative analgesia 72 h postoperatively.

RESULTS

Postoperative IV morphine consumption was significantly reduced during T(0)-T(24) (26 +/- 10 mg vs 52 +/- 29 mg) and T(24)-T(48) (13 +/- 8 mg vs 33 +/- 18 mg) in the controlled-release oxycodone group compared with that in the placebo group. Pain scores at rest, during coughing, and with motion were significantly lower during the first 48 postoperative hours in the controlled-release oxycodone group. Postoperative nausea and vomiting were significantly reduced during the first 24 h in the controlled-release oxycodone group. Lastly, the controlled-release oxycodone group also experienced significantly earlier recovery of bowel function and had higher patient satisfaction with pain therapy.

CONCLUSIONS

Perioperative oral controlled-release oxycodone reduces postoperative IV morphine consumption after lumbar discectomy while providing good analgesia with fewer side effects compared with placebo.

Oxycodone: a pharmacological and clinical review

Oxycodone is a semi-synthetic opioid with an agonist activity on mu, kappa and delta receptors. Equivalence with regard to morphine is 1:2. Its effect commences one hour after administration and lasts for 12 h in the controlled-release formulation. Plasma halflife is 3-5 h (half that of morphine) and stable plasma levels are reached within 24 h (2-7 days for morphine). Oral bioavailability ranges from 60 to 87%, and plasma protein binding is 45%. Most of the drug is metabolised in the liver, while the rest is excreted by the kidney along with its metabolites. The two main metabolites are oxymorphone--which is also a very potent analgesic--and noroxycodone, a weak analgesic. Oxycodone metabolism is more predictable than that of morphine, and therefore titration is easier. Oxycodone has the same mechanism of action as other opioids: binding to a receptor, inhibition of adenylyl-cyclase and hyperpolarisation of neurons, and decreased excitability. These mechanisms also play a part in the onset of dependence and tolerance. The clinical efficacy of oxycodone is similar to that of morphine, with a ratio of 1/1.5-2 for the treatment of cancer pain. Long-term administration may be associated with less toxicity in comparison with morphine. In the future, both opioids could be used simultaneously at low doses to reduce toxicity. It does not appear that there are any differences between immediate and slow-release oxycodone, except their half-life is 3-4 h, and 12 h, respectively. In Spain, controlled-release oxycodone (OxyContin) is marketed as 10-, 20-, 40- or 80-mg tablets for b.i.d. administration. Tablets must be taken whole and must not be broken, chewed or crushed. There is no food interference. The initial dose is 10 mg b.i.d. for new treatments and no dose reduction is needed in the elderly or in cases of moderate hepatic or renal failure. Immediate-release oxycodone (OxyNorm) is also available in capsules and oral solution. Side effects are those common to opioids: mainly nausea, constipation and drowsiness. Vomiting, pruritus and dizziness are less common. The intensity of these side effects tends to decrease over the course of time. Oxycodone causes somewhat less nausea, hallucinations and pruritus than morphine.

Fentanyl and clonidine as adjunctive analgesics with levobupivacaine in paravertebral analgesia for breast surgery

The addition of fentanyl or clonidine to levobupivacaine was evaluated in patients undergoing breast surgery under general anaesthesia with intra- and postoperative paravertebral analgesia. Patients were randomly allocated to four groups: Group L received 19 ml bolus levobupivacaine 0.25% plus 1 ml saline followed by an infusion of levobupivacaine 0.1%; Group LF received 19 ml bolus levobupivacaine 0.25% plus fentanyl 50 microg followed by an infusion of levobupivacaine 0.05% with fentanyl 4 microg x ml(-1); Group LC received 19 ml bolus levobupivacaine 0.25% plus clonidine 150 microg followed by an infusion of levobupivacaine 0.05% with clonidine 3 microg x ml(-1); Group C (control) received general anaesthesia without paravertebral analgesia. All groups received postoperative i.v. morphine patient controlled analgesia (PCA). Although mean (SD) postoperative PCA morphine consumption was decreased in LF [7.9 (4.1) mg] and LC [5.9 (3.5) mg]vs L [27.7 (8.6) mg] or C patients [21.7 (5.5) mg], p < 0.01, paravertebral fentanyl and clonidine were associated with significantly increased vomiting and hypotension, respectively.

Endogenous opiates and behavior: 2004

This paper is the 27th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over 30 years of research. It summarizes papers published during 2004 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.