Controlled-release oxycodone for the management of pediatric postoperative pain

Quantifying the intensity of adverse events with ibuprofen and oxycodone: an observational cohort study

OBJECTIVE

To quantify the frequency and intensity of adverse events (AEs), commonly known as side effects, experienced by children receiving either ibuprofen or oxycodone for pain management following an acute fracture. Secondary objectives were to quantify functional outcome impairment and describe demographic and clinical characteristics associated with AEs.

DESIGN

Observational cohort study.

SETTING

Paediatric emergency department.

PATIENTS

Patients (n=240) aged 4-16 years diagnosed with an acute fracture.

INTERVENTION

Prescribed either ibuprofen (n=179) or oxycodone (n=61) for pain.

MAIN OUTCOME MEASURES

Families were called for the first 3 days after discharge to report the presence and intensity of AEs and their child's functional outcomes (ability to eat, sleep, play or attend school).

RESULTS

On day 1, children using oxycodone were more likely to report any AE (χ² ₁=13.5, p<0.001), nausea (χ² ₁=17.0, p<0.001), vomiting (χ² ₁=11.2, p<0.001), drowsiness (χ² ₁=13.7,p<0.001), constipation (χ² ₁=8.9, p=0.003) and dizziness (χ² ₁=19.1, p<0.001), compared with those using ibuprofen. Children receiving oxycodone reported greater severity of abdominal pain (oxycodone: mean 5.4 SD 3.1; ibuprofen mean 2.5 SD 1.4, F¹ ₁₃=6.5, p=0.02) on day 1 and worse intensity of constipation (oxycodone: mean 4.9 SD 2.1; ibuprofen mean 3.2 SD 2.2, F¹ ₃₃=4.5, p=0.04) over all 3 days. Use of oxycodone was associated with an increased odds of experiencing an AE on day 1 (OR=1.31 (95% CI 1.13 to 1.52)). Higher pain scores (OR=1.50 (95% CI 1.12 to 2.01)), lower extremity fracture (OR=1.25 (95% CI 1.07 to 1.47)) and undergoing ED sedation (OR=1.16 (95% CI 1.01 to 1.34)) were associated with missing school. Higher pain scores (OR=1.50 (95% CI 1.14 to 1.97)) and lower extremity fractures (OR=1.23 (95% CI 1.07 to 1.43)) were also associated with less play.

CONCLUSIONS

Oxycodone is associated with more frequent AEs overall, higher intensity gastrointestinal AEs and greater functional limitations compared with ibuprofen. Lower extremity fractures cause more functional limitations than upper extremity fractures. Clinicians should consider these differences when providing fracture pain care for children.

Experience and Management of the Adverse Effects of Analgesics After Surgery: A Pediatric Patient Perspective

After surgery, the adverse effects (AEs) of analgesics are common and critical factors influencing the postoperative experience of pediatric patients. Inadequate management of AEs has been found to prolong hospital stay, increase readmission rates and decrease satisfaction with care. The aim of this qualitative descriptive study was to better understand the AEs of analgesics from the perspective of adolescent patients with idiopathic scoliosis after spinal surgery. A total of 7 patients participated in the study. Semistructured interviews were conducted at discharge and 1 week after discharge. Transcribed data were analyzed using qualitative content analysis and themes were identified. Overall, participants most frequently reported gastrointestinal and cognitive AEs, with constipation being the most persistent and bothersome. The pediatric participants used a combination of 3 strategies to mitigate analgesic AEs, namely pharmacologic, nonpharmacologic, and reduction of analgesic intake. Participants demonstrated a lack of understanding of AEs and involvement in their own care. Future studies should be conducted to evaluate the efficacy of nonpharmacological strategies in managing analgesic AEs for pediatric patients after surgery.

Population pharmacokinetics of oxycodone: Premature neonates to adults

BACKGROUND

Oxycodone is used in children and adults for the control of acute postoperative pain. Covariate influences such as age, size, and fat mass on oxycodone pharmacokinetic parameters over the human lifespan are poorly quantified.

METHODS

Pooled oxycodone time-concentration profiles were available from preterm neonates to adults. Data from intravenous, intramuscular, buccal, and epidural formulations were analyzed using nonlinear mixed-effects models. Normal fat mass was used to determine the influence of fat on oxycodone pharmacokinetics. Theory-based allometry was used to scale pharmacokinetic parameters to a 70 kg individual. A maturation function described the increase in clearance in neonates and infants.

RESULTS

There were 237 subjects (24 weeks postmenstrual age to 75 years; 0.44-110 kg) providing 1317 plasma concentrations. A three-compartment model with first-order elimination best described oxycodone disposition. Population parameter estimates were clearance (CL) 48.6 L.h^-1 .70 kg^-1 (CV 71%); intercompartmental clearances (Q2) 220 L.h^-1 .70 kg^-1 (CV 64%); Q3 1.45 L.h^-1 .70 kg^-1 ; volume of distribution in the central compartment (V1) 98.2 L.70 kg^-1 (CV 76%); rapidly equilibrating peripheral compartment (V2) 90.1 L. 70 kg^-1 (CV 76%); slow equilibrating peripheral compartment (V3) 28.9 L.70 kg^-1 . Total body weight was the best size descriptor for clearances and volumes. Absorption halftimes (T_ABS ) were: 1.1 minutes for intramuscular, 70 minutes for epidural, 82 minutes for nasogastric, and 159.6 minutes for buccal administration routes. The relative bioavailability after nasogastric administration was 0.673 with a lag time of 8.7 minutes.

CONCLUSIONS

Clearance matured with age; 8% of the typical adult value at 24 weeks postmenstrual age, 33% in a term neonate and reached 90% of the adult clearance value by the end of the first year of life. Allometric scaling using total body weight was the better size descriptor of oxycodone clearance than fat-free mass.

Inpatient postoperative undesirable side effects of analgesics management: a pediatric patients and parental perspective

Introduction

The use of analgesics for the treatment of post-operative pain is common, however, such medications are known to have potential side effects. These undesirable secondary effects can have an important impact on patients and impede their recovery.

Objectives

A review of the literature was conducted in order to gain a better understanding of the challenges confronted by pediatric patients in the acute post-operative period in terms of the side effects of analgesics.

Methods

An online search of keywords (pediatric, analgesic, pain medication, side effects, adverse effects, nausea and vomiting, post-operative, post-discharge, self-care, self-management, management, self-care strategies, patient expectations, patient concerns and education) using PubMed, Medline and Scopus databases, and using the snowballing method of reference tracking was conducted.

Results

A total of 10 studies (N = 10, 871 participants) published between 1990 and 2019 were reviewed. Common side effects experienced by patients were nausea, vomiting, and pruritus. Patients' parents reported having many concerns about analgesic use and reported a lack of knowledge on pain medications and side-effect management.

Conclusion

Areas of improvement in clinical practice include providing the patient and their parents with more information about the post-operative period, analgesic use, and side effects as well as prescribing appropriate treatments to alleviate side effects. This review reveals a lack of qualitative data on pain management and related undesired side effects in pediatric patients having undergone inpatient surgery in addition to the consequences on patients' daily living and on the self-care strategies they engage in to attenuate such effects.

Utility of gabapentin in meeting physical therapy goals following posterior spinal fusion in adolescent patients with idiopathic scoliosis

OF BACKGROUND DATA

Posterior spinal fusion surgery for scoliosis requires extensive postoperative analgesic care. In 2014, we initiated the use of gabapentin as an adjunct for multimodal pain management in spine fusion patients. The effect of gabapentin on postoperative recovery in scoliosis patients was evaluated using the time to meet postoperative physical therapy goals. This measure was chosen because the actions required to achieve the goals are specific and reproducible. Secondary outcomes included morphine equivalents and maximum pain scores.

AIMS

The purpose of this study was to evaluate the effects of gabapentin on time to achieve physical therapy goals following posterior spinal fusion in adolescents with scoliosis.

METHODS

A retrospective chart review was performed and patients treated perioperatively with gabapentin were compared with those who did not receive gabapentin. Outcome measures included the postoperative day that physical therapy goals were met, days to discharge, morphine equivalents, and maximum pain scores. The 4 physical therapy goals included logroll, transition from lying to sitting, ambulate 250 feet, and ascend/descend at least 3 stairs.

RESULTS

There were 50 patients in the gabapentin group and 51 patients in the control group. In the gabapentin group, there was a statistically significant decrease in the time required to meet physical therapy goals. Notably, gabapentin was independently associated with a 5.34 times higher odds of completion of the most challenging physical therapy goal (stairs) within 1 day (P = .04; 95% CI=1.24-37.44). There was not a statistically significant difference in length of hospital stay between the groups (P = .116; 95% CI=0-1).

CONCLUSION

In this retrospective analysis, the use of perioperative gabapentin is associated with a statistically significant decrease in time to completing physical therapy goals after spinal fusion for adolescent idiopathic scoliosis.

Pharmacokinetics, safety and tolerability of a novel tocopheryl phosphate mixture/oxycodone transdermal patch system: a Phase I study

AIM

To characterize the pharmacokinetic profile and evaluate the safety and tolerability of a transdermal oxycodone patch containing tocopheryl phosphate mixture (TPM).

PATIENTS & METHODS

Eleven healthy subjects received a single application of three TPM/oxycodone patches applied to the torso for 72 h.

RESULTS

Oxycodone was detected 8.0 ± 2.7-h postpatch administration, reaching a mean maximum plasma concentration of 3.41 ± 1.34 ng/ml at 49.3 ± 21.2 h. The safety profile was consistent with the application method and known side-effect profile of oxycodone and naltrexone. No treatment-limiting skin irritation was observed.

CONCLUSION

A 3-day application of the TPM/oxycodone patch demonstrated an acceptable safety profile and was well tolerated by healthy subjects, with limited dermal irritation following application.

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.

Perioperative management of the child on long-term opioids

The strategies used to manage children exposed to long-term opioids are extrapolated from adult literature. Opioid consumption during the perioperative period is more than three times that observed in patients not taking chronic opioids. A sparing use of opioids in the perioperative period results in both poor pain management and withdrawal phenomena. The child's pre-existing opioid requirement should be maintained, and acute pain associated with operative procedures should be managed with additional analgesia. This usually comprises short-acting opioids, regional or local anesthesia, and adjuvant therapies. Long-acting opioids, transdermal opioid patches, and implantable pumps can be used to maintain the regular opioid requirement. Intravenous infusion, nurse controlled analgesia, patient-controlled analgesia, or oral formulations are invaluable for supplemental requirements postoperatively. Effective management requires more than simply increasing opioid dose during this time. Collaboration of the child, family, and all teams involved is necessary. While chronic pain or palliative care teams and other staff experienced with the care of children suffering chronic pain may have helpful input, many pediatric hospitals do not have chronic pain teams, and many patients receiving long-term opioids are not palliative. Acute pain services are appropriate to deal with those on long-term opioids in the perioperative setting and do so successfully in many centers. Staff caring for such children in the perioperative period should be aware of the challenges these children face and be educated before surgery about strategies for postoperative management and discharge planning.

Pharmacologic management of acute pediatric pain

The accurate assessment and effective treatment of acute pain in children in the hospital setting is a high priority. During the past 2 to 3 decades, pediatric pain management has gained tremendous knowledge with respect to the understanding of developmental neurobiology, developmental pharmacology the use of analgesics in children, the use of regional techniques in children, and of the psychological needs of children in pain. A wide range of medications is available to treat a variety of pain types. This article provides an overview of the most common analgesic medications and techniques used to treat acute pain in children.

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.

Advanced practice nurse-directed telephone management of acute pain following pediatric spinal fusion surgery

PURPOSE

Children undergoing spinal fusion surgery require sophisticated pain management. This study describes an integrated system of pain management primarily directed by an advanced practice nurse (APN), encompassing both the inpatient and outpatient settings.

DESIGN AND METHODS

A retrospective chart review was conducted. Pain management and patient education began in the hospital. The APN provided telephone-based follow-up and management after discharge.

RESULTS

An average of four phone calls over 9 days was required per patient. No complications were reported.

PRACTICE IMPLICATIONS

Results of this study support the APN telephone management of postoperative pain once children are discharged following extensive surgery.

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%.

Pediatric acute pain management

Children are benefiting from the advances made in developmental neurobiology and analgesic pharmacology over the past few decades. Heightened public awareness and increased political pressure from external regulatory agencies are helping to maintain the momentum in improving pediatric pain management. As a result, methods of assessing and managing children's pain are being refined, and new modalities of pain relief are being explored. This review summarizes selected current topics in pediatric acute pain management, with the major emphasis on acute postoperative pain management.

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.

Marked variation in oxycodone pharmacokinetics in infants

BACKGROUND

The pharmacokinetics of oxycodone (13-hydroxy-7,8-dihydrocodeinone) has been studied in adults and in children who are older than 6 months but there is no information on the disposition of oxycodone in neonates and young infants. The aim of this study was to study the pharmacokinetics of oxycodone in infants varying in age from 0 to 6 months.

METHODS

Twenty-two infants undergoing surgery were given postoperatively an intravenous bolus of 0.1 mg.kg(-1) of oxycodone hydrochloride. Ten of the patients were younger than 1 week (group 1), six from 1 week to 2 months (group 2) and six from 2 to 6 months (group 3). Plasma samples were collected for the analysis of oxycodone concentrations up to 24 h. Pharmacokinetics were characterized by noncompartmental methods.

RESULTS

The median (range) values for the clearance (Cl) were 9.9 (2.3-17.2), 20.1 (3.7-40.4) and 15.4 (14.8-80.2) ml.min(-1).kg(-1) in the above three groups. The values for volume of distribution at steady-state were 3.3 (1.9-4.7), 5.6 (1.3-8.5) and 3.2 (1.8-6.0) l.kg(-1) and for elimination half-life (t(1/2)) 4.4 (2.4-14.1), 3.6 (1.6-11.6) and 2.0 (0.8-3.9) h, respectively. Both Cl (r = 0.46) and half-life (r = -0.46) were correlated to the age of the patient (P < 0.05). There were 13 patients who were on mechanical ventilation at the time of oxycodone administration. None of the spontaneously breathing infants had hypoventilation which required assistance during the study.

CONCLUSIONS

The values for Cl and t(1/2) varied greatly between the subjects. This variability was most pronounced in the two youngest groups. Routine dosing of oxycodone in young infants may be dangerous. The dose of oxycodone must be titrated individually.