The use of transdermal fentanyl in pediatric oncology palliative care

A Narrative Review of Pain in Pediatric Oncology: The Opioid Option

Opioid therapy is the mainstay for managing pain in pediatric oncology. This narrative review describes the current literature regarding opioids for pediatric cancer pain. The review explores the multifaceted landscape of opioid utilization in this population, including the role of opioids in certain clinical circumstances, modalities of opioid delivery, unique opioids, outpatient and at-home pain management strategies, and other key concepts such as breakthrough pain. This review highlights the importance of individualized dosing and multimodal approaches to enhance efficacy and minimize adverse effects. Drawing from a wide range of evidence, this review offers insights to optimize pediatric oncology pain management.

An Open-Label Study of the Pharmacokinetics and Tolerability of Once-a-Day Fentanyl Citrate Patch in Japanese Pediatric and Adolescent Patients with Cancer Pain

BACKGROUND

Transdermal fentanyl is not yet approved for pediatric and adolescent use in Japan.

OBJECTIVE

Serum fentanyl concentration and the safety and efficacy of once-a-day fentanyl citrate patch were investigated in pediatric and adolescent patients with cancer pain.

METHODS

In this open-label, uncontrolled study, cancer patients aged 2-19 years being treated with strong opioid analgesics were switched to fentanyl citrate patch for 2 weeks. Serum fentanyl concentration was measured at steady state, and severity of pain was evaluated.

RESULTS

Eleven patients (four patients aged 2-5 years and seven patients aged 6-19 years) were enrolled. No patient received a dose exceeding 2 mg. Mean serum fentanyl concentrations after administration of 0.5 mg, 1 mg, and 2 mg were 144 pg/mL (n = 4), 277 pg/mL (n = 3), and 2070 pg/mL (n = 4), respectively. All patients were included in the efficacy and safety analysis, but one patient was excluded from the pharmacokinetic analysis because blood was sampled on the day after blood transfusion. A subgroup analysis showed that the mean serum fentanyl concentration tended to be higher in pre-school patients (aged 2-5 years) than in school-aged and adolescent patients (aged 6-19 years) and than in reports of adult patients (aged 20 years and above) who received the same dose. No respiratory adverse events were observed, and pain was well controlled.

CONCLUSION

Fentanyl citrate patch tended to result in a higher serum fentanyl concentration in pre-school patients than in school-aged, adolescent, and adult patients who received the same dose. The patch provided adequate pain control, was well tolerated, and did not cause respiratory adverse events.

TRIAL REGISTRATION NUMBER

JPRN-JapicCTI-183909.

Pharmacokinetics, pharmacodynamics and pharmacogenetics associated with nonsteroidal anti-inflammatory drugs and opioids in pediatric cancer patients

INTRODUCTION

Advancing appropriate and adequate analgesic pharmacotherapy in pediatric patients with cancer is an area of clinical need. Few studies have been performed to evaluate the selection of an analgesic and appropriate dosing corresponding to analgesic effect among pediatric cancer patients. This review describes information related to pharmacokinetic, pharmacodynamic, and pharmacogenomic (when applicable) considerations for analgesics that are commonly used to manage pain experienced by pediatric patients with cancer. Areas covered: Analgesics commonly used to treat pediatric patients with malignancy patterned after the World Health Organization's 'analgesic ladder' for cancer pain management. Expert opinion: Addressing pain management safely and effectively in pediatric patients with cancer will require advances in both drug development, to increase the armament of analgesics available for children, and our pharmacologic understanding of those analgesics in current use. However, performing the necessary types of studies to develop new analgesics, or gain knowledge of existing therapy, within a population that is relatively small, diverse, and who experience pain originating from a variety of sources, is a tremendous challenge.

Transdermal Fentanyl for Cancer Pain Management in Opioid-Naive Pediatric Cancer Patients

BACKGROUND

 Transdermal therapeutic system fentanyl with a drug release rate of 12 µg/h should be of special value in pediatric cancer pain control. Such a fentanyl formulation allows for a stepwise dose increase, similar to that reported for sustained-release morphine.

PATIENTS AND METHODS

 Sixty-four male and female pediatric patients with moderate to severe chronic cancer pain, ages ranging 2-14 years, were included. Patients did not receive opioids prior to enrollment. Patients were observed for pain relief using the Visual Analog Scale and the Wong-Baker FACES Pain Rating Scale, play performance score, and for side effects.

RESULTS

 There was significant improvement of visual analog scale and FACES pain scores from the baseline to the second day of application (P < 0.001). By the 15th day, scores reached 1.18 ± 0.393 and 1.13 ± 0.35, respectively (P < 0.001). Play performance scale improved from the third day of application of the patch when compared with the baseline (P < 0.001), reaching 55.02 ± 8.35 (P < 0.001) at the end of the study. The sedation score increased on the second day to 2 in 10 patients and to 3 in 54 patients. By the seventh day, 56 patients had a sedation score of 1. All patients returned to baseline by the 15th day. Itching was reported in 16 cases, and erythema occurred in 10 cases. No significant side effects were reported.

CONCLUSION

 Transdermal fentanyl was found to be an effective, safe, and well-tolerated treatment for pediatric cancer-related pain in opioid-naive patients with chronic moderate to severe pain. In this study population, evaluation of vital signs and physical examination did not suggest any safety concerns while using transdermal fentanyl.

Treatment of Pain in Pediatric Patients

A growing body of evidence demonstrates that untreated pain is associated with adverse consequences that can compromise clinical and developmental outcomes in children but that these adverse consequences can be prevented or attenuated by appropriate analgesic therapy. Thus, effective treatment of acute pain must be a clinical priority for children of all ages. Over the past 20 years, extensive pediatric research exploring pain assessment, developmental pharmacology of analgesics, and the clinical use of analgesics has dispelled many myths and misconceptions about pain management in pediatric patients; proven that analgesics can be used safely in neonates, infants, and children; and provided a framework for the development of pediatric pain management guidelines. This article reviews guidelines recommended for managing acute pain in pediatric patients and the treatment options for children experiencing acute pain. Contemporary issues regarding acetaminophen, nonsteroidal anti-inflammatory agents, and opioids are discussed.

Pediatric palliative care: use of opioids for the management of pain

Pediatric palliative care (PPC) is provided to children experiencing life-limiting diseases (LLD) or life-threatening diseases (LTD). Sixty to 90% of children with LLD/LTD undergoing PPC receive opioids at the end of life. Analgesia is often insufficient. Reasons include a lack of knowledge concerning opioid prescribing and adjustment of opioid dose to changing requirements. The choice of first-line opioid is based on scientific evidence, pain pathophysiology, and available administration modes. Doses are calculated on a bodyweight basis up to a maximum absolute starting dose. Morphine remains the gold standard starting opioid in PPC. Long-term opioid choice and dose administration is determined by the pathology, analgesic effectiveness, and adverse effect profile. Slow-release oral morphine remains the dominant formulation for long-term use in PPC with hydromorphone slow-release preparations being the first rotation opioid when morphine shows severe adverse effects. The recently introduced fentanyl transdermal therapeutic system with a drug-release rate of 12.5 microg/hour matches the lower dose requirements of pediatric cancer pain control. Its use may be associated with less constipation compared with morphine use. Though oral transmucosal fentanyl citrate has reduced bioavailability (25%), it inherits potential for breakthrough pain management. However, the gold standard breakthrough opioid remains immediate-release morphine. Buprenorphine is of special clinical interest as a result of its different administration routes, long duration of action, and metabolism largely independent of renal function. Antihyperalgesic effects, induced through antagonism at the kappa-receptor, may contribute to its effectiveness in neuropathic pain. Methadone also has a long elimination half-life (19 [SD 14] hours) and NMDA receptor activity although dose administration is complicated by highly variable morphine equianalgesic equivalence (1 : 2.5-20). Opioid rotation to methadone requires special protocols that take this into account. Strategies to minimize adverse effects of long-term opioid treatment include dose reduction, symptomatic therapy, opioid rotation, and administration route change. Patient- or nurse-controlled analgesia devices are useful when pain is rapidly changing, or in terminal care where analgesic requirements may escalate. In this article, we present detailed pediatric pharmacokinetic and pharmacodynamic data for opioids, their indications and contraindications, as well as dose-administration regimens that include practical strategies for opioid switching and dose reduction. Additionally, we discuss the problem of hyperalgesia and the use of adjuvant drugs to support opioid therapy.

Opioid use in palliative care of children and young people with cancer

OBJECTIVE

Identify opioids prescribed, preferred routes, and doses among children with incurable cancer.

STUDY DESIGN

Prospective survey with monthly questionnaires regarding patients 0 to 19 years old from oncology centers. Data were collected by professionals on each patient for 6 months or until death, and analyzed from patients who died. Impact of tumor was analyzed with Kruskal-Wallis and Mann-Whitney tests. Major opioid dosages are expressed as oral morphine equivalents.

RESULTS

Of 185 children recruited, 164 (88 boys, 76 girls) died. Mean palliative care duration was 67 days. One hundred forty-seven (89.6%) received major opioids. Morphine, diamorphine, and fentanyl were prescribed in 75%, 57.9%, and 11.6%, respectively. Seventy-three (44.5%) received >1 major opioid. Median monthly maximum doses prescribed rose from 2.1 mg/kg/24 h (study entry) to 4.4 mg/kg/24 h (death) (P < .001); overall variable (0.09-1500 mg/kg/24 h, median 3.7 mg/kg/24 h). Opioids were given by the oral (117/164, 71.3%), intravenous (68/164, 41.5%), subcutaneous (40, 28%), rectal (20, 12.2%), and transdermal (18, 11%) routes. There was a shift to intravenous use as death approached. Numbers within each tumor group were too small to show significance. Children with solid tumors outside the central nervous system were likely to receive more opioids, be given multiple different opioids, and receive opioids in the last month.

CONCLUSIONS

The study shows the United Kingdom practice of opioid use and provides comparator data for practice in children's palliative medicine.

The management of pain in children with life-limiting illnesses

The management of pain in children with life-limiting illnesses is complex and unfortunately not often done effectively. Pain is a multidimensional symptom that can overshadow all other experiences of both the child and family. This article focuses on topics common to practitioners caring for children with lifelimiting illnesses, including a review of myths and obstacles to achieving adequate pain control, a review of the pathophysiology of pain, an overview of the use of opioids in children, an approach to the management of neuropathic pain, and a brief discussion of nonpharmacologic pain management strategies.

Transdermal fentanyl in childhood and adolescence: a comprehensive literature review

The recently introduced fentanyl transdermal therapeutic system (TTS) with a drug release rate of 12.5 microg/h matches the lower dosing requirements of cancer pain control in children. It is likely that fentanyl TTS will be used in pediatrics with increasing frequency. We compiled the published evidence on pediatric applications of this drug formulation to help physicians get the most benefit from its use. Within this systematic review, a total of 11 observational clinical or pharmacokinetic studies were identified. There are no pediatric randomized or controlled cohort studies. Pharmacokinetic studies poorly described time-concentration profiles after application. The time to reach steady-state serum drug concentrations seems to be longer, clearance (expressed as liters per kilogram per hour) higher, and elimination half-life shorter in children than in adults. There are no fundamental differences in effect or profile of adverse effects compared with adults. Fentanyl TTS may be associated with less constipation compared with morphine use. Frequently, pediatric patients need supplemental mechanical fixation of the fentanyl TTS by means of medical tape. Younger patients tend to have a higher fentanyl requirement when referenced to body weight. Both parents and medical professionals are satisfied with fentanyl TTS to a higher degree than with individual analgesic pretreatment regimens. Fentanyl TTS is a promising option for chronic pain control in children. An approximate conversion factor of 45 mg/day oral morphine to 12.5 microg/h fentanyl TTS is used for initial therapy dose estimation in children receiving long-term morphine therapy. This is conservatively low to avoid respiratory depression. Daily oral morphine equivalent dose should be at least 30 mg/d before fentanyl TTS therapy is started with 12.5 microg/h. Evidence for superiority of fentanyl TTS treatment above conventional opioid administration is both scarce and of low quality.

PERSPECTIVE

The article gives a comprehensive overview of all pediatric data concerning the fentanyl TTS. Children may take longer to reach steady-state fentanyl serum concentrations than adults, and younger children may require higher doses referenced to body weight than older children or adults. Consequently, there is a need to provide sufficient medication in the phase of therapy initiation to prevent breakthrough pain. The 72-hour dosing schedule recommended by the manufacturers may not be applicable to children because of poor patch adhesiveness. The authors suggest to ensure firm fixation of the fentanyl TTS with additional medical tape if necessary and to change the fentanyl TTS after 48 hours. Transdermal fentanyl in children may exhibit fewer side effects when compared with other opioids, especially constipation. Randomized studies are urgently needed to definitively answer this question.

Ensuring pain relief for children at the end of life

Pain management in the context of pediatric palliative care can be challenging. The present article reviews, through a case-based presentation, the nonpharmacological and pharmacological methods used to ensure adequate pain control in children facing end of life. Details on the impressive range of opioid dosages required and routes of administration are highlighted from published literature and clinical experience. Where available, evidence-based recommendations are provided. Potential side effects of pain medication and barriers to good pain control are discussed. Novel analgesics and innovative delivery methods are presented as future tools enhancing pain relief at the end of life. Some challenges to ethically grounded research in this important context of care are reviewed.

Pain in children who have life-limiting conditions

Children and adolescents who have life-limiting conditions are vulnerableto acute and chronic pain problems. Many compounding and complicatingfactors often need to be explored in this setting. Barriers to effective painmanagement include poor assessment and measurement of pain anda lack of specialist knowledge. Fears regarding the use of opioids and theirassociation with the end of life must be addressed openly and with clarity.Day-to-day management should include continual appraisal of pain issuesif quality of life is to be maximized. Pain is a complicated phenomenon. The impact of pain and the compli-cated dynamic of suffering in children and young people who have life-lim-iting conditions must not be underestimated. The clinician must be vigilantand take responsibility for all aspects of pain management in these patients.

Transdermal fentanyl in the management of children with chronic severe pain: results from an international study

BACKGROUND

The current study was conducted to assess the safety and tolerability of a transdermal fentanyl delivery system for the relief of chronic pain in a pediatric population, and also to validate titration recommendations and conversion to transdermal fentanyl from oral opioid therapy.

METHODS

This 15-day (with 3-month extension), single-arm, open-label trial was conducted at 66 sites in 10 countries. A total of 199 pediatric patients (ages 2-16 years) with both malignant and nonmalignant conditions who were receiving oral or parenteral opioids for moderate to severe chronic pain were enrolled. Transdermal fentanyl doses were titrated upward according to the rescue medication consumed during the previous application period. Degree of pain was assessed by patients and parents/guardians using visual and numeric scales. Level of play and quality of life were assessed using the Play Performance Scale (PPS) and the Child Health Questionnaire (CHQ). Adverse events were monitored on Days 1-15. Hypoventilation and sedation were monitored every 4 hours during the first 72 hours of the study.

RESULTS

A total of 173 patients completed the primary treatment period and 130 entered the extension phase. The average daily pain intensity scores were reported to have decreased by Day 16 and improvements in the mean PPS scores were observed to the end of the extension period. The CHQ scores demonstrated improvements in 11 of 12 domains after Month 1 of the extension period.

CONCLUSIONS

Transdermal fentanyl was found to be a safe and well tolerated alternative to oral opioid treatment for children ages 2-16 years who were previously exposed to opioid therapy.

Strong opioids in pediatric palliative medicine

The management of pain in the palliative care of children is somewhat different from that in adults. It also differs in approach from the management of other types of acute and chronic pain in childhood. Whereas once opioids were thought to be highly dangerous drugs, unsuitable for use in children, they have now taken their place as the mainstay for provision of good analgesia to manage moderate-to-severe pain in both malignant and non-malignant life-limiting conditions. There are relatively little clinical or laboratory data regarding opioids specifically in children. However, much of what has been published regarding the management of pain in palliative medicine in adults can be extrapolated. On saying that, early research in children does suggest some significant differences in opioid pharmacokinetics, particularly with respect to morphine clearance, which seems to be faster in adults. Thus, the use of opioids in pediatric palliative care presents some unique challenges. Confident and rational use of opioids by pediatricians, illustrated by the WHO guidelines, is essential for the adequate management of pain complicating the palliative phase in children with life-limiting conditions.

Cancer pain management in children

Unrelieved pain may have a major impact on the care of children with cancer. The type and severity of pain experienced by children with cancer varies from acute, procedure-related pain to progressive chronic pain associated with the progression of the disease or sequelae of treatment. Drugs are the mainstay of treatment. Regular pain assessments combined with appropriate analgesic administration at regular dosing intervals, adjunctive drug therapy for control of adverse effects and associated symptoms, and nonpharmacological interventions are recommended. Although standard dosing of opioids adequately treats most cancer pain in children, more complex treatment is required by a significant group. Strategies to improve analgesia include the use of epidural or intrathecal infusions of a combination of opioids and other adjuvants, or other regional anaesthesia techniques. Procedure- and treatment-related pain is an even greater problem than cancer pain. Recommendations have been published with regard to the monitoring and personnel required when children are sedated which aim to set the standard of care and minimize both physical discomfort or pain and negative psychological responses, by providing analgesia; and to maximize the potential for amnesia; and to control behaviour.