Analgesic efficacy of controlled-release oxycodone in postoperative pain

Risks and benefits of oral modified-release compared with oral immediate-release opioid use after surgery: a systematic review and meta-analysis

Prescription of modified-release opioids for acute postoperative pain is widespread despite evidence to show their use may be associated with an increased risk of adverse effects. This systematic review and meta-analysis aimed to examine the available evidence on the safety and efficacy of modified-release, compared with immediate-release, oral opioids for postoperative pain in adults. We searched five electronic databases from 1 January 2003 to 1 January 2023. Published randomised clinical trials and observational studies on adults who underwent surgery which compared those who received oral modified-release opioids postoperatively with those receiving oral immediate-release opioids were included. Two reviewers independently extracted data on the primary outcomes of safety (incidence of adverse events) and efficacy (pain intensity, analgesic and opioid use, and physical function) and secondary outcomes (length of hospital stay, hospital readmission, psychological function, costs, and quality of life) up to 12 months postoperatively. Of the eight articles included, five were randomised clinical trials and three were observational studies. The overall quality of evidence was low. Modified-release opioid use was associated with a higher incidence of adverse events (n = 645, odds ratio (95%CI) 2.76 (1.52-5.04)) and worse pain (n = 550, standardised mean difference (95%CI) 0.2 (0.04-0.37)) compared with immediate-release opioid use following surgery. Our narrative synthesis concluded that modified-release opioids showed no superiority over immediate-release opioids for analgesic consumption, length of hospital stay, hospital readmissions or physical function after surgery. One study showed that modified-release opioid use is associated with higher rates of persistent postoperative opioid use compared with immediate-release opioid use. None of the included studies reported on psychological function, costs or quality of life.

No place for routine use of modified-release opioids in postoperative pain management

Modified-release opioid tablets were introduced into surgical practice in the belief that they provided superior pain relief and reduced nursing workload, and they rapidly became embedded into many perioperative pathways. Although national and international guidelines for the management of postoperative pain now advise against the use of modified-release opioids, they continue to be prescribed in many centres. Recognition that modified-release opioids show lack of benefit and increased risk of harm compared with immediate-release opioids in the acute, postoperative setting has become clear. Their slow onset and offset make rapid and safe titration of these opioids impossible, including down-titration as the patient recovers; pain relief may be less effective; they have been associated with an increased incidence of opioid-related adverse drug events, increased length of hospital stay, and higher readmission rates; and they lead to higher rates of opioid-induced ventilatory impairment and persistent postoperative opioid use. Evidence indicates that modified-release opioids should not be used routinely in the postoperative period.

The effectiveness and safety of the rapid titration strategy of background controlled-release oxycodone hydrochloride for patients with moderate-to-severe cancer pain: A retrospective cohort study

BACKGROUND

Oxycodone hydrochloride is a semisynthetic narcotic analgesic agent. This study aimed to explore optimal titration strategy of controlled-release (CR) oxycodone hydrochloride in patients with cancer pain.

METHODS

258 patients, who used regular strong opioids (morphine and CR oxycodone hydrochloride) for cancer pain across 25 three grade class hospitals in China during January 15th 2017 to April 30th 2017, were retrospectively studied. The patients were divided into 4 groups according to treatment regimens titrated. The pain remission rate and numeric rating scale (NRS) of cancer pain was recorded at 0, 12, 24, 36, 48, 60, 72 h after opioid titration. The incidence of adverse events (AEs) with therapy were also observed.

RESULTS

12 h after treatment, pain remission rate of Group B, C and D was significantly higher (P < 0.001) than Group A. For the complete remission rate, there were also significant differences among the four groups (P < 0.001). No significant difference was found among four groups for pain remission rate at 24, 72 h after treatment. Multiple comparison of NRS scores showed that the both Group B and C varied significantly with Group D (P = 0.028, P = 0.05, respectively), showing superior analgesic effect over Group D. AEs were significantly different among groups (P < 0.01), with the most frequent AEs in Group A, lowest in Group B.

CONCLUSION

The rapid titration strategy of background CR oxycodone hydrochloride was effectiveness and safety in patients with moderate-to-severe cancer pain.

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.

Sedation, Analgesia, and Paralysis in COVID-19 Patients in the Setting of Drug Shortages

The rapid spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has led to a global pandemic. The 2019 coronavirus disease (COVID-19) presents with a spectrum of symptoms ranging from mild to critical illness requiring intensive care unit (ICU) admission. Acute respiratory distress syndrome is a major complication in patients with severe COVID-19 disease. Currently, there are no recognized pharmacological therapies for COVID-19. However, a large number of COVID-19 patients require respiratory support, with a high percentage requiring invasive ventilation. The rapid spread of the infection has led to a surge in the rate of hospitalizations and ICU admissions, which created a challenge to public health, research, and medical communities. The high demand for several therapies, including sedatives, analgesics, and paralytics, that are often utilized in the care of COVID-19 patients requiring mechanical ventilation, has created pressure on the supply chain resulting in shortages in these critical medications. This has led clinicians to develop conservation strategies and explore alternative therapies for sedation, analgesia, and paralysis in COVID-19 patients. Several of these alternative approaches have demonstrated acceptable levels of sedation, analgesia, and paralysis in different settings but they are not commonly used in the ICU. Additionally, they have unique pharmaceutical properties, limitations, and adverse effects. This narrative review summarizes the literature on alternative drug therapies for the management of sedation, analgesia, and paralysis in COVID-19 patients. Also, this document serves as a resource for clinicians in current and future respiratory illness pandemics in the setting of drug shortages.

Kappa opioid agonists reduce oxycodone self-administration in male rhesus monkeys

RATIONALE

Combinations of mu and kappa opioid receptor (KOR) agonists have been proposed as potential analgesic formulations with reduced abuse liability. The current studies extend previous work by investigating the typical KOR agonist, salvinorin A, and the atypical KOR agonist, nalfurafine, as deterrents of oxycodone self-administration using a progressive ratio (PR) schedule of reinforcement.

METHODS

In separate experiments, adult male rhesus monkeys (N = 4/experiment) were trained under a PR schedule of reinforcement to self-administer cocaine (0.1 mg/kg/injection) and saline on alternating days. Oxycodone (0.01-0.1 mg/kg/injection) alone and combined with salvinorin A (experiment 1; 0.006, 0.012 mg/kg/injection) or nalfurafine (experiment 2; 0.0001-0.00032 mg/kg/injection) were tested within the alternating cocaine and saline baseline. The mechanism of nalfurafine's effects on oxycodone self-administration was investigated via pretreatment with the KOR antagonist, nor-binaltorphimine (nor-BNI; 10 mg/kg; i.m.).

RESULTS

All subjects self-administered oxycodone alone above saline levels at sufficiently large doses, and combining salvinorin A or nalfurafine with oxycodone reduced the mean number of injections per session to saline levels (experiment 1) or to levels that were significantly lower than oxycodone alone (experiment 2). The ability of nalfurafine to reduce oxycodone self-administration was reversed by pretreatment with nor-BNI.

CONCLUSIONS

These results demonstrate that KOR agonists, including the clinically used KOR agonist, nalfurafine, can punish self-administration of a prescription opioid analgesic, oxycodone, in rhesus monkeys and that nalfurafine's punishing effect is KOR-dependent. Combinations of KOR agonists with prescription opioids may have reduced abuse liability.

Controlled Release of Oxycodone as an Opioid Titration for Cancer Pain Relief: A Retrospective Study

BACKGROUND In 2014, a Chinese expert consensus was proposed regarding a titration protocol with controlled-release (CR) oxycodone as a background dose for relieving the moderate to severe cancer pain. This work aimed to summarize its efficacy and safety in our hospital. MATERIAL AND METHODS The Good Pain Management (GPM) protocol comprises a CR morphine or oxycodone given every 12-hours as a background dose and an immediate-release (IR) opioid as a rescue dose. Cancer patients with moderate to severe cancer pain were treated with this protocol, and the successful titration (numerical rating scale [NRS] ≤3 within 3 days) rate was analyzed. SPSS was used for statistical analysis. Differences of variables between opioid intolerant patients and opioid tolerant patients were analyzed using the Mann-Whitney U test. The chi square test was used for comparison of frequencies in different groups. A P-value.

Controlled-release oxycodone improves pain management after uterine artery embolisation for symptomatic fibroids

AIM

To evaluate if pre- and post-procedure administration of controlled-release oxycodone (CRO) in combination with standard analgesia improves pain control and decreases the amount of required post-procedure opioids in uterine fibroid embolisation (UFE).

MATERIALS AND METHODS

Between January 2009 and March 2010, 60 consecutive women were prospectively randomised in two groups for UFE: the control group, in which 30 patients underwent the standard anaesthetic procedure and the CRO group, in which 30 patients underwent the standard anaesthetic procedure with the addition of CRO. Age, pain, nausea/vomiting, fibroid volume, length of hospital stay, and use and dose of morphine received via the patient-controlled analgesia (PCA) device in both groups were evaluated to compare the two methods of pain control. Fibroid volume as measured at magnetic resonance imaging (MRI) was evaluated for correlation with post-embolisation pelvic pain over a period of 24 hours.

RESULTS

A significant difference was seen in the pain scores at 24 hours (p=0.029), with less pain in the CRO group. More patients from the control group required morphine (p=0.017), and at higher levels (p=0.130). Pruritus was lower in patients of the CRO group, probably because they received less morphine (p=0.029). No correlation was seen between leiomyoma volume and pain levels over 24 hours (Spearman's ρ=0.02; p=0.881). Length of hospital stay was not different between the two groups.

CONCLUSION

The addition of CRO to standard analgesia for UFE provides more effective analgesia, with a reduction in pain scores in 24 hours, less morphine use, and decreased side effects, mainly pruritus.

Design and in vivo evaluation of oxycodone once-a-day controlled-release tablets

The aim of present study was to design oxycodone once-a-day controlled-release (CR) tablets and to perform in vitro/in vivo characterizations. Release profiles to achieve desired plasma concentration versus time curves were established by using simulation software and reported pharmacokinetic parameters of the drug. Hydroxypropyl methylcellulose (HPMC) 100,000 mPa·s was used as a release modifier because the polymer was found to be resistant to changes in conditions of the release study, including rotation speed of paddle and ion strength. The burst release of the drug from the CR tablets could be suppressed by applying an additional HPMC layer as a physical barrier. Finally, the oxycodone once-a-day tablet was comprised of two layers, an inert HPMC layer and a CR layer containing drug and HPMC. Commercial products, either 10 mg bis in die (bid [twice a day]) or once-a-day CR tablets (20 mg) were administered to healthy volunteers, and calculated pharmacokinetic parameters indicated bioequivalence of the two different treatments. The findings of the present study emphasize the potential of oxycodone once-a-day CR tablets for improved patient compliance, safety, and efficacy, which could help researchers to develop new CR dosage forms of oxycodone.

Systematic literature review and meta-analysis of the efficacy and safety of prescription opioids, including abuse-deterrent formulations, in non-cancer pain management

OBJECTIVE

This study was conducted to compare safety and efficacy outcomes between opioids formulated with technologies designed to deter or resist tampering (i.e., abuse-deterrent formulations [ADFs]) and non-ADFs for commonly prescribed opioids for treatment of non-cancer pain in adults.

METHODS

PubMed and Cochrane Library databases were searched for opioid publications between September 1, 2001 and August 31, 2011, and pivotal clinical trials from all years; abstracts from key pain conferences (2010-2011) were also reviewed. One hundred and ninety-one publications were initially identified, 68 of which met eligibility criteria and were systematically reviewed; a subset of 16 involved a placebo group (13 non-ADFs vs placebo, 3 ADFs vs placebo) and reported both efficacy and safety outcomes, and were included for a meta-analysis. Summary estimates of standardized difference in mean change of pain intensity (DMCPI), standardized difference in sum of pain intensity difference (DSPID), and odds ratios (ORs) of each adverse event (AE) were computed through random-effects estimates for ADFs (and non-ADFs) vs placebo. Indirect treatment comparisons were conducted to compare ADFs and non-ADFs.

RESULTS

Summary estimates for standardized DMCPI and for standardized DSPID indicated that ADFs and non-ADFs showed significantly greater efficacy than placebo in reducing pain intensity. Indirect analyses assessing the efficacy outcomes between ADFs and non-ADFs indicated that they were not significantly different (standardized DMCPI [0.39 {95% confidence interval (CI) 0.00-0.76}]; standardized DSPID [-0.22 {95% CI -0.74 to 0.30}]). ADFs and non-ADFs both were associated with higher odds of AEs than placebo. Odds ratios from indirect analyses comparing AEs for ADFs vs non-ADFs were not significant (nausea, 0.87 [0.24-3.12]; vomiting, 1.54 [0.40-5.97]; dizziness/vertigo, 0.61 [0.21-1.76]; headache, 1.42 [0.57-3.53]; somnolence/drowsiness, 0.47 [0.09-2.58]; constipation, 0.64 [0.28-1.49]; pruritus 0.41 [0.05-3.51]).

CONCLUSION

ADFs and non-ADFs had comparable efficacy and safety profiles, while both were more efficacious than placebo in reducing pain intensity.

Double-Blind, Randomized Comparison of the Analgesic and Pharmacokinetic Profiles of Controlled- and Immediate-Release Oral Oxycodone in Cancer Pain Patients

Thirty patients with cancer pain completed a double-blind crossover study comparing controlled-release (CR) and immediate-release (IR) oxycodone. In open-label titration (2 to 21 days), these patients were stabilized on IR oxycodone qid. They were then randomized to double-blind treatment with CR oxycodone q12h or IR oxycodone qid for 3 to 7 days followed by crossover at the same daily dose. Mean (+/- SD) pain intensity (0 = none to 10 = severe) decreased from a baseline of 6.0 +/- 2.2 to 2.7 +/- 1.1 after titration with IR oxycodone dosed qid. Pain intensity remained stable throughout double-blind treatment: 2.7 +/- 1.9 with CR oxycodone and 2.8 +/- 1.9 with IR oxycodone. Acceptability of therapy and pain scores correlated with plasma oxycodone concentrations for each interval and were similar for both medications (IR and CR oxycodone). Adverse events were similar for both formulations. Following repeat dosing under double-blind conditions, oral CR oxycodone administered q12h provided analgesia comparable to IR oxycodone given qid.

Prolonged-release Oxycodone/Naloxone in Postoperative Pain Management: From a Randomized Clinical Trial to Usual Clinical Practice

Objective:

These studies evaluated the feasibility of using oral prolonged-release oxycodone/naloxone (OXN PR) for the management of acute postoperative pain.

Methods:

Three studies were undertaken: (i) the analgesic efficacy of OXN PR was compared with prolonged-release oxycodone (OXY PR) in patients with knee arthroplasty in an immediate postoperative period (IPOP) study; (ii) OXN PR treatment was compared with other opioids during rehabilitation after knee arthroplasty in a noninterventional study (NIS); and (iii) surgical patients on other opioids were switched to OXN PR postoperatively during a quality improvement programme (QIP).

Results:

In the IPOP study, the pain intensity at rest score decreased by a similar amount in the OXN PR and OXY PR groups, indicating similar analgesic efficacies. In the NIS, patient assessments indicated enhanced efficacy and tolerability for OXN PR compared with other opioids. The QIP indicated significant improvements in bowel function and less difficulty passing urine at the end of OXN PR treatment compared with baseline. No safety concerns were raised.

Conclusions:

The analgesic efficacies of OXN PR and OXY PR were similar in postoperative pain settings. OXN PR reduced the degree of restriction in relation to patients carrying out physio - therapy compared with other opioids, and improved bowel and bladder function.

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.

Opioid analgesics and the risk of fractures in older adults with arthritis

OBJECTIVES

To compare the risk of fracture associated with initiating opioids with that of nonsteroidal anti-inflammatory drugs (NSAIDs) and the variation in risk according to opioid dose, duration of action, and duration of use.

DESIGN

Retrospective cohort study.

SETTING

Two statewide pharmaceutical benefit programs for persons aged 65 and older.

PARTICIPANTS

Twelve thousand four hundred thirty-six initiators of opioids and 4,874 initiators of NSAIDs began treatment between January 1, 1999, and December 31, 2006. Mean age at initiation of analgesia was 81; 85% of participants were female, and all had arthritis.

MEASUREMENTS

Cox proportional hazards models, adjusted for several potential confounders, quantified fracture risk. Study outcomes were fractures of the hip, humerus or ulna, or wrist, identified using a combination of diagnosis (International Classification of Diseases, Ninth Revision, Clinical Modification) and procedure (Common Procedural Terminology) codes.

RESULTS

There were 587 fracture events among the participants initiating opioids (120 fractures per 1,000 person-years) and 38 fracture events among participants initiating NSAIDs (25 fractures per 1,000 person-years) (hazard ratio (HR)=4.9, 95% confidence interval (CI)=3.5-6.9). Fracture risk was greater with higher opioid dose. Risk was greater for short-acting opioids (HR=5.1, 95% CI=3.7-7.1) than for long-acting opioids (HR=2.6, 95% CI=1.5-4.4), even in participants taking equianalgesic doses, with differential fracture risk apparent for the first 2 weeks after starting opioids but not thereafter.

CONCLUSION

Older people with arthritis who initiate therapy with opioids are more likely to experience a fracture than those who initiate NSAIDs. For the first 2 weeks after initiating opioid therapy, but not thereafter, short-acting opioids are associated with a greater risk of fracture than are long-acting opioids.

A randomized, controlled trial of oxycodone versus placebo in patients with postherpetic neuralgia and painful diabetic neuropathy treated with pregabalin

The aim of this randomized double-blind, placebo-controlled, parallel-group study was to evaluate the efficacy, safety, and tolerability of pregabalin in combination with oxycodone or placebo, in patients with either postherpetic neuralgia (PHN) or painful diabetic neuropathy (PDN). After a 7-day washout period, 62 patients were randomized to receive either oxycodone mixture 10 mg/day or placebo mixture for 1 week. Patients were then started on open-label pregabalin (75, 150, 300 and 600 mg/day) according to a forced titration dosing regimen, while continuing the same dosage of oxycodone or placebo for 4 weeks. The primary efficacy measure was a decrease in the pain-intensity score of at least 2cm and a pain score <4cm measured using a 10-cm visual analogue scale (VAS) following pregabalin dosage escalation and treatment for 4 weeks. Secondary efficacy measures included sleep interference and the Neuropathic Pain Scale. There were similar levels of overall efficacy between pregabalin/oxycodone and pregabalin/placebo groups in relieving PHN and PDN related pain.

PERSPECTIVE

Peripheral neuropathic pain presents commonly in clinical practice, and 2 of its most prevalent types are PHN and PDN. Currently available treatments provide some degree of pain relief in approximately 40-60% of patients, leaving the remainder with unremitting pain. Although this study supports the effectiveness of pregabalin in the treatment of PHN or PDN, it also shows that the addition of a low dose of oxycodone at 10mg/day does not enhance the pain-relieving effects of pregabalin.

Single dose oral oxycodone and oxycodone plus paracetamol (acetaminophen) for acute postoperative pain in adults

BACKGROUND

Oxycodone is a strong opioid agonist used to treat severe pain. It is commonly combined with milder analgesics such as paracetamol. This review updates a previous review that concluded, based on limited data, that all doses of oxycodone exceeding 5 mg, with or without paracetamol, provided analgesia in postoperative pain, but with increased incidence of adverse events compared with placebo. Additional new studies provide more reliable estimates of efficacy and harm.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral oxycodone, with or without paracetamol, in acute postoperative pain in adults.

SEARCH STRATEGY

Cochrane CENTRAL, MEDLINE, EMBASE and Oxford Pain Relief Database, searched in May 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered oxycodone, with or without paracetamol, in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants remedicating over specified time periods, and time-to-use of rescue medication, were sought as additional measures of efficacy. Adverse events and withdrawals information was collected.

MAIN RESULTS

This updated review includes 20 studies, with 2641 participants. For oxycodone 15 mg alone compared with placebo, the NNT for at least 50% pain relief was 4.6 (95% Confidence Interval 2.9 to 11). For oxycodone 10 mg plus paracetamol 650 mg, the NNT was 2.7 (2.4 to 3.1). A dose response was demonstrated for this outcome with combination therapy. Duration of effect was 10 hours with oxycodone 10 mg plus paracetamol 650 mg, and 4 hours with half that dose. Fewer participants needed rescue medication over 6 hours at the higher dose. Adverse events occurred more frequently with combination therapy than placebo, but were generally described as mild to moderate in severity and rarely led to withdrawal.

AUTHORS' CONCLUSIONS

Single dose oxycodone is an effective analgesic in acute postoperative pain at doses over 5 mg; oxycodone is two to three times stronger than codeine. Efficacy increases when combined with paracetamol. Oxycodone 10 mg plus paracetamol 650 mg provides good analgesia to half of those treated, comparable to commonly used non-steroidal anti-inflammatory drugs, with the benefit of longer duration of action.

Controlled-release oxycodone is better tolerated than intravenous tramadol/metamizol for postoperative analgesia after retinal-surgery

PURPOSE

We assessed the clinical efficacy and tolerance of controlled-release oxycodone (CRO), comparing it with intravenous tramadol/metamizol combination in this prospective, randomised, double-blind study of 35 ASA physical status I-III patients undergoing retinal-surgery.

METHODS

General anaesthesia using remifentanil and propofol was performed for surgery. On arrival in the recovery room patients were randomly allocated to two groups. The controlled-release oxycodone group (CRO Group) received 10 mg CRO. 12 h after the initial dose another 10 mg CRO were administered. Simultaneously with the initial CRO dose, and every 4 h up to 24 h postoperatively, the CRO Group received intravenous isotonic saline infusion. On arrival in the recovery room the tramadol/metamizol group (TM Group) received a placebo tablet, and 12 h later a second placebo. Simultaneously 100 mg tramadol combined with 1 g metamizol were administered intravenously every 4 h until 24 h postoperatively. All patients had access to intravenous opioid rescue medication.

RESULTS

The AUC for quality of analgesia was significantly higher in the CRO Group than in the TM Group (p = 0.0023). Patient rated quality of analgesia significantly higher in the CRO Group than in the TM Group 8 h (p = 0.048), 16 h (p = 0.009) and 24 h (p = 0.001) postoperatively. There was no statistical difference in AUC for pain scores between groups (p = 0.205). The CRO Group experienced significantly less nausea than the TM Group (p = 0.012). Six patients in the TM Group in contrast to none in the CRO Group interrupted the study before finishing the study protocol (p = 0.022).

CONCLUSIONS

We conclude that CRO administered twice in the first 24 h postoperatively is superior to intravenous tramadol/metamizol for postoperative analgesia after retinal surgery, with fewer adverse events and greater patient satisfaction.

Oxycodone: a review of its use in the management of pain

BACKGROUND

Oxycodone is a strong opioid that acts at mu- and kappa-opioid receptors. It has pharmacological actions similar to strong opioids, but with a specific pharmacologic profile and greater analgesic potency to morphine. The efficacy of oxycodone in managing neuropathic and somatic pain, both of malignant and non-malignant origin, has been established in a wide range of settings.

SCOPE

This review aims to provide a comprehensive evaluation of oxycodone and its role within clinical settings in order to provide an evidence-based perspective on its use in the clinic. Literature searches using Medline, EMBASE and Cochrane Databases were used to compile data for review. The review provides information on the pharmacokinetics and pharmacodynamics of oxycodone and also profiles established clinical data in neuropathic and somatic pain as well as emerging data to support the use of oxycodone in visceral pain, which may be due to its interaction with kappa-opioid receptors. Oxycodone is available in a range of formulations for oral, intraspinal and parenteral administration.

FINDINGS

The prolonged-release form of oxycodone offers a fast onset of analgesia, controlling pain for 12 hours and providing clinically meaningful relief of moderate to severe pain and improving quality of life across a broad spectrum of pain types.

CONCLUSIONS

Oxycodone provides significant pain relief. It has relevant points of difference from other opioids and as such may be a suitable alternative to morphine.

Early oral analgesia after fast-track cardiac anesthesia

PURPOSE

Oral analgesia after "fast-track" cardiac anesthesia has not been explored. The aim of this study was to compare two oral oxycodone analgesic regimens.

METHODS

One hundred-twenty patients scheduled for coronary artery bypass grafting were randomly assigned postoperatively to receive immediate-release oxycodone 5 mg and acetaminophen 325 mg (Percocet-5) (group I) per os four times daily, or controlled-release oxycodone 10 mg (OxyContin) (group II) per os every 12 hr and placebo twice daily. Acetaminophen 500 mg per os was used as first-line rescue medication, and immediate-release oxycodone (syrup form) 5 mg per os as second-line rescue medication. Pain intensity was assessed with a visual analogue scale on the first postoperative day, the morning after extubation, and thereafter four times daily for four days. Use of rescue medication and adverse events were recorded.

RESULTS

Baseline demographic and operation-related characteristics were similar in both groups. While pain control was good in both groups, the immediate-release group experienced less pain on all postoperative days (P = 0.003), required significantly less rescue medication, and had fewer adverse effects such as somnolence and nausea.

CONCLUSION

Peroral oxycodone is effective for early pain control after fast-track cardiac anesthesia. Immediate-release oxycodone/ acetaminophen appears to provide better analgesia and fewer side effects compared to controlled-release oxycodone.

Efficacy and Tolerability of Oxycodone Hydrochloride Controlled-Release Tablets in Moderate to Severe Cancer Pain

BACKGROUND AND OBJECTIVE

Oxycodone is a semisynthetic opioid analgesic drug classed as a strong opioid. The controlled-release oxycodone tablet formulation (OCRT) was approved in China in 2004 for management of moderate to severe cancer pain. Few data about the efficacy of OCRT and clinical outcomes in Chinese patients taking this drug are available. The purpose of this study was to evaluate the efficacy and tolerability of this drug for relief of moderate to severe cancer pain in Chinese patients.

METHODS

This was a prospective, open-label, multicentre clinical trial carried out in ten hospitals in Zhejiang Province, China. Patients with cancer pain with a score > or =4 (numerical rating scale) were enrolled. They received oral OCRT at an initial dosage of 5mg every 12 hours for patients scoring 4-6 and 10mg every 12 hours for patients scoring > or =7. Doses were then titrated on an individual basis. Onset of analgesic action, pain score and quality-of-life (QOL) scores - including items measuring family understanding and support, sleep, mental state, appetite, fatigue, and activities of daily life - were evaluated. Adverse effects were also documented.

RESULTS

216 patients (126 males and 90 females) aged 22-84 years were enrolled. The total mean OCRT dosage was 445.2 +/- 361.6mg (range 130-2320mg). The daily dosages of the vast majority of cases (89%) were between 10mg and 30mg. Onset of analgesic action occurred within 1 hour in 198 cases (91.7%) following administration of OCRT. 82.4% of cases were titrated to a steady dosage level within 2 days following administration of the first dose of medication. Pain score decreased significantly (p < 0.01) from 7.1 +/- 1.2 at baseline to 2.3 +/- 1.2 one week after starting medication and 1.8 +/- 0.9 four weeks after starting medication. Scores on all six QOL items increased significantly (p < 0.01) compared with baseline but showed varying rates of improvement. Adverse events included constipation, nausea, vomiting, drowsiness and dysuria. These were noted most frequently in the first week (25.5% of patients) and lessened over time. No severe adverse events were noted.

CONCLUSION

We conclude that OCRT is well tolerated and effective in controlling moderate to severe cancer pain in Chinese patients.

Pain relief following breast augmentation surgery: a comparison between incisional patient-controlled regional analgesia and traditional oral analgesia

BACKGROUND AND OBJECTIVES

Postoperative pain is a common problem following ambulatory breast augmentation surgery. This study was performed to compare standard of care (oral analgesics) with patient-controlled incisional regional analgesia (PCRA) for postoperative pain management at home for 48 h. A second aim was to compare the analgesic efficacy of ropivacaine 0.25% vs. 0.5%.

METHODS

Surgery was performed under local anaesthesia and monitored anesthesia care. Sixty adults (ASA 1-2) were randomized to one of two groups. Patients in Group PCRA could self-administer ropivacaine 0.25% 10 mL in the left breast and ropivacaine 0.5% in the right breast. Patients in Group T (tablets) received our standard of care treatment, i.e. oral paracetamol 1 g four times a day and oral ibuprofen 500 mg three times a day. Parameters measured included: analgesic requirements (in post-anesthesia care unit, PACU and post-discharge), pain intensity (visual analogue scale), patient satisfaction, global analgesia, side-effects, and quality of recovery.

RESULTS

Pain scores were significantly lower in Group PCRA compared to Group T at all time periods (P < 0.05). No differences were found in pain scores between the right and left breasts. Significantly more patients in Group T requested analgesics in the recovery unit (27 vs. 7; P = 0.001) and also at home (20 vs. 11; P < 0.02). More patients in the tablet group had nausea and vomiting (10 vs. 3; P < 0.05). Global analgesia on day 2 was significantly better in PCRA group; however, patient satisfaction was similar in both groups. More patients in the tablet group had sleep disturbance and woke up at night due to pain.

CONCLUSIONS

Pain relief after ambulatory breast augmentation is superior with incisional PCRA when compared to oral analgesic combination of paracetamol and ibuprofen. Incisional PCRA was associated with minimal side-effects and less sleep disturbance. There was no difference in the analgesic efficacy between ropivacaine 0.25% and 0.5%.

Multicenter, open-label, prospective evaluation of the conversion from previous opioid analgesics to extended-release hydromorphone hydrochloride administered every 24 hours to patients with persistent moderate to severe pain

BACKGROUND

Hydromorphone hydrochloride is a mu-opioid agonist with dose-dependent analgesic properties. Extended-release hydromorphone hydrochloride (ER hydromorphone HCl) capsules have been developed for administration every 24 hours.

OBJECTIVES

This prospective evaluation focused on the first (ie, conversion) phase of 2 identically designed, randomized, controlled studies that compared the safety and efficacy of once-daily ER hydromorphone HCl capsules with immediate-release hydromorphone hydrochloride (IR hydromorphone HCl) tablets administered 4 times daily in the treatment of persistent moderate to severe cancer- and noncancer-related pain.

METHODS

Patients being treated with opioid analgesics for persistent moderate to severe pain were converted to ER hydromorphone HCl using an 8:1 conversion ratio. The dose was titrated to attain an average pain intensity (API) score < or = 4 on a 0- to 10-point numeric rating scale. Supplemental oral IR hydromorphone HCl tablets were used as rescue medication at a dose of one eighth to one sixth of the daily ER hydromorphone HCl dose.

RESULTS

A total of 343 patients (272 [79%] with cancer pain; mean age, 57.8 years) were enrolled and converted to ER hydromorphone HCl from their previous opioids. About half (51%) were women. At baseline, the mean (SD) API score was 5.3 (2.1). Mean (SD) API scores were 4.7 (2.0) after the first 48 hours and 3.4 (2.1) by the end of titration. After 4 to 21 days of titration, 239 (70%) patients reached stabilization defined as a > or = 48-hour period with an API score of < or =4, unchanged ER hydromorphone HCl dose, and < or = 2 rescue doses per day. The stabilized patients had mean (SD) API scores of 2.7 (1.1) at the end of titration. At stabilization, 102 (43%) of 239 patients remained at their initial conversion dose, 129 (54%) had a dose increase, and 8 (3%) had a dose decrease. Frequent (> or =10% of patients) adverse events that occurred within the first 48 hours after conversion and during the entire titration phase were nausea, somnolence, headache, constipation, vomiting, and dizziness.

CONCLUSION

In this prospective evaluation of the conversion and titration phase of 2 randomized, controlled studies, a conversion ratio of 8:1 mg of oral morphine to oral ER hydromorphone HCl was found to be clinically useful in patients with persistent moderate to severe cancer-related or noncancer-related pain.

Oxycodone

Oxycodone has been in clinical use since 1917. Parenteral oxycodone was used mainly for the treatment of acute postoperative pain whereas combinations, for example, oxycodone and acetaminophen, were used for moderate pain. Since the introduction of controlled-release oxycodone, it has been used to manage cancer-related pain and chronic non-cancer-related pain problems. Controlled studies have been performed in postoperative pain, cancer pain, osteoarthritis-related pain, and neuropathic pain due to postherpetic neuralgia and diabetic neuropathy. The pharmacodynamic effects of oxycodone are typical of a mu-opioid agonist. Oxycodone closely resembles morphine but it has some distinct differences, particularly in its pharmacokinetic profile. Being an old drug, the basic pharmacology of oxycodone has been a neglected field of research.

The use of controlled-release versus scheduled oxycodone in the immediate postoperative period following total joint arthroplasty

This prospective study examined whether better pain control could be achieved in the first 48 hours after joint arthroplasty with controlled-release oxycodone compared to scheduled oxycodone with acetaminophen. In the study group, controlled-release oxycodone was administered on the day of surgery and was continued during patients' hospital stay. The study group then was compared to a previous group in which effective pain control was obtained with around-the-clock oxycodone with acetaminophen. Findings indicated controlled-release oxycodone did not provide better pain control compared to scheduled oxycodone with acetaminophen in the first 48 hours following total joint arthroplasty.

Pain management in ambulatory surgery

Successful ambulatory surgery is dependent on analgesia that is effective, has minimal adverse effects, and can be safely managed by the patient at home after discharge. A number of studies have identified that the provision of effective postoperative analgesia is inadequate for a significant proportion of patients. The following discussion details the current available analgesic options for ambulatory surgery patients and the rationale for their use. Preemptive analgesia should be given to all patients unless there are specific contraindications. Consideration should be given to the use of long-acting oral COX-2 selective nonsteroidal anti-inflammatory drugs (NSAIDs) and long-acting oral opioids to treat postoperative pain. A standardized multimodal postdischarge analgesic regimen tailored to the patient's expected postoperative pain levels should be prescribed. Patient follow-up by telephone questionnaire will confirm those surgical procedures that result in mild or moderate-to-severe postoperative pain and the effectiveness of treatment plans.

Controlled-release oxycodone for the management of pediatric postoperative pain

Studies addressing pain management after pediatric spinal fusion surgery have focused on the use of patient-controlled or epidural analgesia during the immediate postoperative period. Controlled-release (CR) analgesics have been found to be safe and effective in adults. The purpose of this study was to describe the use of oxycodone-CR in pediatric patients after the immediate postoperative period. A retrospective chart review of 62 postoperative spinal fusion patients (10-19 years) was conducted. The mean initial oxycodone-CR dose was 1.24 mg/kg/day. The mean ratio of conversion from parenteral morphine equivalents to oxycodone-CR was 1:1. Mean pain scores decreased from 4.2/10 to 3.7/10 with the transition to oxycodone-CR. Common side effects included dizziness, constipation, and nausea. Oxycodone-CR was used for an average of 13.3 days, which included an average wean time of 6 days. Results of this study demonstrate safe and effective use of oxycodone-CR in the pediatric spinal fusion population.

Controlled-release codeine is equivalent to acetaminophen plus codeine for post-cholecystectomy analgesia

PURPOSE

Following ambulatory surgery, long-acting analgesics may provide advantages over short-acting analgesics. This study compared controlled-release codeine (CC) and acetaminophen plus codeine (A/C; 300 mg/30 mg) for pain control in the 48-hr period following laparoscopic cholecystectomy.

METHODS

Eligible patients were randomized to CC or A/C in a double-blind, double-dummy parallel group study. Unrelieved pain in hospital was treated with fentanyl i.v. bolus. Pain [100 mm visual analogue scale (VAS)] was assessed before the first dose of medication; at 0.5, one, two, three, and four hours post-dose; at discharge; and three times a day for 48 hr. Adverse events were recorded and measures of patient satisfaction were assessed at the end of the study.

RESULTS

Eighty-four patients were enrolled in the study; 42 patients in each group. There were no statistically significant differences between CC and A/C treatment. Mean VAS baseline pain was similar in both groups (P = 0.49) and there was no significant difference in the time to onset of analgesia (P = 0.17). At 0.5 hr, the mean VAS pain score was significantly reduced from baseline in both groups (P = 0.0001). The VAS pain scores at discharge were reduced 59% and 56% from baseline, respectively (P = 0.61). There was no difference between treatments in the incidence of adverse events and patients reported similar levels of satisfaction.

CONCLUSIONS

Controlled-release codeine provides an equivalent onset of analgesia, reduction in postoperative pain, and level of patient satisfaction, to acetaminophen plus codeine, over 48 hr following cholecystectomy, with the advantage of less frequent dosing.

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

OBJECTIVE

To assess clinical efficacy of controlled-release oxycodone (CRO) 20 mg on a 12-h dosing schedule in this prospective, randomised, placebo-controlled, double-blinded study of 40 ASA physical status I-III women undergoing breast surgery for cancer.

RESEARCH DESIGN AND METHODS

General anaesthesia using remifentanil and propofol was performed for surgery. Both groups received premedication with oral midazolam 7.5 mg 1 h before surgery. In the controlled-release oxycodone group, one tablet of 20 mg CRO was administered with the premedication, and 12 h after the premedication another 20 mg CRO. In the placebo (PL) group, a placebo tablet was administered with the premedication, and 12 h later another placebo tablet. All patients had access to opioid rescue medication via an IV patient-controlled analgesia (PCA) device.

MAIN OUTCOME MEASURES

Area under the curve (AUC), based on IV opioid rescue consumption over 24 h postoperatively.

RESULTS

The AUC for IV PCA opioid consumption was significantly lower in the CRO group than in the PL group (p = 0.01). The CRO group required less IV opioid loading dose (p < 0.001), and consumed less opioid rescue medication 4 h (p = 0.036), 16 h (p = 0.01), and 24 h (p = 0.005) postoperatively. AUC for VAS scores at rest was significantly lower in the CRO group than in the PL group (p = 0.05). VAS scores at rest were lower in the CRO group 16 h (p = 0.04) and 24 h (p = 0.03) postoperatively. There was no difference in AUC for pain scores on movement (p = 0.103) and for quality of analgesia (p = 0.139). There was no difference in nausea between groups (p = 0.34). Pruritus, arterial hypotension or hypertension, bradycardia, and tachycardia were not observed in either treatment group. None of the patients showed signs of confusion, agitation, or respiratory depression.

CONCLUSIONS

The administration of CRO 20 mg on a 12-h dosing schedule halves postoperative IV PCA opioid consumption. CRO 20mg is effective in preventing pain after breast surgery for cancer with only mild side-effects.

Randomized, double-blind, placebo-controlled comparison of the analgesic efficacy of oxycodone 10 mg/acetaminophen 325 mg versus controlled-release oxycodone 20 mg in postsurgical pain

This randomized, controlled trial compared the analgesic efficacy and safety of the new oxycodone 10-mg/acetaminophen 325-mg formulation (Percocet) for the treatment of acute pain following oral surgery with double the dose of oxycodone alone (controlled-release [CR] oxycodone 20 mg [OxyContin]). A total of 150 male and female patients with > or = 2 full or partial bone-impacted mandibular molars, at least moderate persistent pain, and moderate trauma received a single dose of combination agent, CR oxycodone, or placebo following oral surgery and rated pain intensity and pain relief over the next 6 hours. The intent-to-treat population comprised 141 patients (55 on combination agent, 56 on oxycodone, and 30 on placebo). Combination agent and CR oxycodone were significantly superior to placebo for all efficacy measures. Combination agent was statistically superior to CR oxycodone in four of five outcome measures of pain intensity and pain relief (PPID, PPAR, SPID, and SPRID). It also provided a faster onset and 24% reduction in the number of patients reporting treatment-related adverse events compared with twice the dose of opioid alone. This new formulation offers the combination of two analgesic drugs with complementary mechanisms of action, which results in enhanced analgesia, an "opioid-sparing" effect, and an improved side effect and safety profile.

Conversion to oral controlled-release oxycodone from intravenous opioid analgesic in the postoperative setting

OBJECTIVE

This study assessed conversion factors utilized by physicians to transfer postoperative patients from intravenous opioids to oral controlled-release (CR) oxycodone and the subsequent analgesic effectiveness.

DESIGN

This was a multicenter, open-label, usual-use study of 189 hospitalized postoperative patients receiving opioid (usually morphine) intravenous patient-controlled analgesia (IV PCA) for at least 12 to 24 hours post-procedure. Patients who were tolerant of oral medications and without signs of paralytic ileus were converted to oral CR oxycodone, given every 12 hours for up to 7 days.

RESULTS

The mean (+/-SE) conversion factor used to convert IV PCA morphine to CR oxycodone was 1.2 +/- 0.1 (N=159). The initial CR oxycodone doses, based on individual conversion factors from IV PCA morphine, produced significant reductions in pain intensity (scores <or=4) within 6 hours after the initial dose. The mean +/- SE initial dose of CR oxycodone, for patients converted from IV PCA morphine, was 27 +/- 1 mg; that for all patients was 29 +/- 2 mg. Pain at the end of the first 12 hours was controlled with these initial doses. The most common adverse events were constipation, nausea, and pruritus.

CONCLUSIONS

Administered at least 12 hours following abdominal, orthopedic, or gynecologic surgery, an initial oral CR oxycodone dose calculated by multiplying the amount of IV morphine used in the previous 24 hours (immediate postoperative period) by a conversion factor of 1.2, on average, provided adequate pain control during the subsequent 12-hour dosing interval and for a maximum of 7 days. Adverse events were consistent with opioid side effects.

Over-the-counter oral analgesia for postcesarean pain

OBJECTIVE

The purpose of this study was to evaluate patient satisfaction for oral analgesia for postcesarean pain management.

STUDY DESIGN

A prospective study was conducted on women who underwent cesarean section with regional analgesia. Women were treated with ibuprofen 400 mg in liquid-filled capsules on the first postoperative day by two modes of drug administration: on patient demand (n = 60) and at predetermined regular intervals (n = 54). Pain intensity and satisfaction were self-evaluated by the patients with use of a visual analog scale.

RESULTS

Patients in the fixed time interval group had lower pain scores (by 38%-54%, P <.001) compared with the on-demand group. Satisfaction scores in both groups were high but superior in the fixed time interval group (87.5 +/- 18.8, median 94.5, vs 78.6 +/- 21, median 85, P <.001).

CONCLUSIONS

Oral, nonnarcotic, postcesarean analgesia provides satisfactory pain relief. Patient satisfaction can be further enhanced by providing the medications in fixed time intervals rather than leaving it to patient request.

Preoperative administration of controlled-release oxycodone for the management of pain after ambulatory laparoscopic tubal ligation surgery

STUDY OBJECTIVE

To examine the analgesic efficacy of administering controlled-release (CR) oxycodone 10 mg before elective ambulatory laparoscopic tubal ligation surgery.

DESIGN

Randomized, double-blind study.

PATIENTS

50 healthy women presenting for elective ambulatory laparoscopic tubal ligation surgery.

SETTING

Ambulatory surgery center of a university hospital.

INTERVENTIONS

Fifty patients were administered either placebo (n = 25) or CR oxycodone 10 mg (n = 25) 1 hour before surgery. All patients were administered a similar general anesthetic. In the postanesthesia care unit (PACU), fentanyl 25 microg was administered for a verbal analog scale (VAS) pain score >or=3. Patients were discharged home when they were awake and alert, had stable vital signs, were able to void, tolerated oral fluids, experienced no side effects, had a VAS <or=3, and were able to ambulate without assistance. While at home, patients were instructed to take 1 to 2 acetaminophen 325 mg/oxycodone 5 mg tablets, every 3 hours as needed for a VAS >or=3.

MEASUREMENTS

VAS pain scores and the frequency of postoperative nausea and vomiting were recorded in the PACU. While at home, patients were contacted by telephone after surgery and asked about their pain score, time to first analgesic use, frequency of postoperative nausea and vomiting, and total acetaminophen/oxycodone use in the 24 hours following surgery.

MAIN RESULTS

Patients in the CR oxycodone group had a shorter time to discharge (p < 0.001), reported lower postoperative pain scores (p < 0.001), lower frequency of postoperative nausea and vomiting (p < 0.05), longer time to first analgesic use (p < 0.0,001), and required less fentanyl in the PACU (p < 0.01) and fewer acetaminophen/oxycodone tablets in the 24 hours following surgery.

CONCLUSION

The preoperative administration of CR oxycodone 10 mg is an effective analgesic technique in the management of pain following ambulatory laparoscopic tubal ligation surgery, and may facilitate earlier postoperative discharge.

Advancement of opioid analgesia with controlled-release oxycodone

Optimal pharmacologic management of pain requires selection of the appropriate analgesic drug, prescription of the appropriate dose, administration of the analgesic by the appropriate route, scheduling of the appropriate dosing interval, prevention of persistent pain and relief of breakthrough pain, aggressive titration of the dose of the analgesic, prevention, anticipation, and management of analgesic side-effects, use of appropriate co-analgesic drugs, and consideration of sequential trials of opioid analgesics. Controlled-release oxycodone (CRO) has the characteristics of an 'ideal' opioid analgesic drug: short half-life, long duration of action, predictable pharmacokinetics, absence of clinically active metabolites, rapid onset of action, easy titration, no ceiling dose, minimal adverse effects, and minimal associated stigma. CRO has been shown to be effective in the control of pain caused by cancer, osteoarthritis, post-herpetic neuralgia, major surgery, and degenerative spine disease.

Opioid formulations: tailoring to the needs in chronic pain

Opioids are one of the standard therapies used in the management of chronic pain. They were first widely adopted for the treatment of chronic pain associated with cancer and are now considered important in the alleviation of non-cancer and neuropathic pain. Around-the-clock (ATC) medication has been found to be an effective approach in treating chronic pain. Guidelines issued by the American Pain Society (1999) note that in most cases the preferred route of administering opioids is oral, because of convenience, flexibility, and relative steadiness of the opioid concentrations in the blood. The advantages of ATC therapy and oral medication are some of the reasons for the development of controlled-release, oral formulations of opioids (e.g. morphine, oxycodone, hydromorphone, and hydrocodone). The reduced dosing frequency makes the oral medication more convenient for patients, making it easier for them to comply with the dosing regimen. ATC therapeutic coverage and the possible increased compliance afforded by controlled-release formulations can make opioids even more effective in managing chronic pain.