Dermal delivery of amitriptyline for topical analgesia.

Amitriptyline, administered orally, is currently one of the treatment options for the management of neuropathic pain and migraine. Because of the physicochemical properties of the molecule, amitriptyline is also a promising candidate for delivery as a topical analgesic. Here we report the dermal delivery of amitriptyline from a range of simple formulations. The first stage of the work required the conversion of amitriptyline hydrochloride to the free base form as confirmed by nuclear magnetic resonance (NMR). Distribution coefficient values were measured at pH 6, 6.5, 7, and 7.4. Solubility and stability of amitriptyline were assessed prior to conducting in vitro permeation and mass balance studies. The compound demonstrated instability in phosphate-buffered saline (PBS) dependent on pH. Volatile formulations comprising of isopropyl alcohol (IPA) and isopropyl myristate (IPM) or propylene glycol (PG) were evaluated in porcine skin under finite dose conditions. Compared with neat IPM, the IPM:IPA vehicles promoted 8-fold and 5-fold increases in the amount of amitriptyline that permeated at 24 h. Formulations containing PG also appear to be promising vehicles for dermal delivery of amitriptyline, typically delivering higher amounts of amitriptyline than the IPM:IPA vehicles. The results reported here suggest that further optimization of topical amitriptyline formulations should be pursued towards development of a product for clinical investigational studies.

Use of home parenteral nutrition in severely neurologically impaired children.

OBJECTIVE: To review the outcome of children with severe neurological impairment (NI) and intestinal failure (IF) referred to our specialist multidisciplinary IF rehabilitation service and to discuss implications. DESIGN: Case report series, descriptive analysis. SETTING: IF rehabilitation programme at a tertiary children's hospital in the UK. PATIENTS: Children with severe NI referred to our IF rehabilitation programme from 2009 to 2019. MAIN OUTCOME MEASURES: Demographic and social data, diagnosis, clinical condition, use of home parenteral nutrition (HPN), complications, ethics review outcome and advance care plans. RESULTS: Six patients with severe NI were referred to our IF rehabilitation service. Consent for publication was obtained from five families. After thorough medical review and clinical ethics committee assessment, three children started HPN, one had intravenous fluids in addition to enteral feed as tolerated and one intravenous fluids only. The HPN children survived 3-7.08 years (median 4.42 years) on treatment. Objective gastrointestinal signs, for example, bleeding improved without excessive HPN-related complications. Symptomatic improvement was less clear. Analgesia was reduced in three of the five children. All cases had detailed symptom management and advance care plans regularly updated. CONCLUSIONS: HPN can play a role in relieving gastrointestinal signs/symptoms in children with severe NI and IF. HPN can be conceptualised as part of good palliative care if judged to be in the child's best interests. However, given its risks and that HPN has the potential to become inappropriately life-sustaining, a thorough ethics review and evaluation should be performed before it is initiated, withheld or withdrawn in children with severe NI.

Artificial nutrition and hydration for children and young people towards end of life: consensus guidelines across four specialist paediatric palliative care centres.

There is a paucity of evidence on the role, use, benefit and challenges of artificial nutrition and hydration (ANH) in children at end of life. Parents express the difficulty they face with making the decision to withdraw ANH. Decision-making on the role of ANH in an individual child requires careful multidisciplinary team deliberation and clear goals of care with children and families. Four paediatric palliative care specialist centres reviewed the current literature and developed consensus guidelines on ANH at end of life. These guidelines seek to provide a practical approach to clinical decision-making on the role of ANH in a child or young person entering the end-of-life phase.

Investigation of binary and ternary solvent systems for dermal delivery of methadone.

Methadone appears to be a promising candidate for pain management. Previously, we conducted a comprehensive characterization study of methadone base and evaluated the dermal delivery of methadone from various neat solvents. Four solvents, namely d-limonene (LIM), ethyl oleate (EO), Transcutol® P (TC) and octyl salicylate (OSAL), were identified as the optimal neat solvents for skin delivery of the compound. To explore further approaches to improve methadone permeation, the present work investigated a range of binary and ternary vehicles. In vitro permeation studies in porcine skin confirmed that binary systems delivered significantly higher (p < 0.05) amounts of methadone through the skin compared with neat solvents. The highest skin permeation was observed for formulations composed of propylene glycol (PG) and TC. Nine formulations were subsequently examined in human skin. A good correlation (r2 = 0.80) for methadone permeation was obtained between porcine ear skin and human skin data. Solvent uptake studies indicated that the presence of PG not only increased methadone permeation but also TC permeation. The drug appears to "track" the permeation of TC. Future studies will expand further the range of potential vehicles for optimal delivery of the drug, that will ultimately to be investigated in clinical studies.

Preparation, Characterization and Dermal Delivery of Methadone.

The use of methadone for the management of pain has received great interest in recent years. Currently, oral and intravenous formulations are available for clinical use. Dermal delivery represents an attractive alternative route of administration for this drug as it is associated with comparatively fewer side effects. The first stage of the work was the preparation of methadone free base as this form of the drug is expected to permeate the skin to a greater extent than the hydrochloride salt. Subsequently the molecule was characterized with Nuclear Magnetic Resonance (NMR) and thermal analysis, the distribution coefficient was determined and solubility studies were conducted in a range of solvents. In vitro permeation and mass balance studies were conducted under finite dose conditions (5 µL/cm2) in porcine skin. The results confirmed the more favorable penetration of methadone free base compared with the salt. The highest cumulative amount of methadone (41 ± 5 µg/cm2) permeated from d-limonene (LIM). Ethyl oleate (EO), Transcutol® P (TC) and octyl salicylate (OSAL) also appear to be promising candidate components of dermal formulations for methadone base. Future work will focus on further formulation optimization with the objective of progressing to evaluation of prototype dosage forms in clinical trials.

Parallel planning and the paediatric critical care patient.

A growing number of children with life-limiting conditions (LLCs) are being cared for in paediatric critical care (PCC) settings. Children with LLCs admitted to PCC are at a high risk of developing complications and many die after prolonged admissions. Relatively few of these patients and their parents or carers have had documented discussions about their wishes for care in the event of a serious clinical deterioration before admission to PCC. There is a need for improved understanding of (1) how parents arrive at decisions regarding what is best for their child at times of critical illness and (2) the role of parallel planning and advance care plans in that process. This review examines the complexities of decision-making in children with LLCs who are admitted to PCC settings.

Use of buccal morphine in the management of pain in children with life-limiting conditions: Results of a laboratory study.

BACKGROUND: Children and infants with impaired swallow or compromised enteral absorption require alternative routes for administration of analgesia. Recent clinical guidance and practice for paediatric palliative care teams, who often treat such children, supports buccal morphine sulphate as a fast acting, effective and easily administered agent for pain relief. However, a consideration of the physicochemical properties and potency of morphine would suggest that it is not a suitable candidate for delivery via the transmucosal route, raising questions about its use in children and infants. AIM: To explore the permeability of buccal morphine sulphate in an established ex vivo porcine buccal mucosa as a necessary step in examining efficacy for use in children with life-limiting conditions and life-threatening illnesses. DESIGN: A permeation study conducted with morphine sulphate in an ex vivo porcine buccal tissue model. Flux values and pharmacokinetic data were used to calculate the plasma values of morphine that would result following buccal administration in a 20kg child. RESULTS: Results show that the estimated steady state plasma values of morphine sulphate following buccal administration in this model do not achieve minimum therapeutic concentration. CONCLUSION: These data strongly suggest that morphine sulphate is not suitable for buccal administration and that further research is needed to establish its efficacy in relief of pain in children with life-limiting conditions and life-threatening illnesses.

Pharmacological interventions for pain in children and adolescents with life-limiting conditions.

BACKGROUND: Pain is one of the most common symptoms in children and young people (CYP) with life-limiting conditions (LLCs) which include a wide range of diagnoses including cancer. The current literature indicates that pain is not well managed, however the evidence base to guide clinicians is limited. There is a clear need for evidence from a systematic review to inform prescribing. OBJECTIVES: To evaluate the evidence on the effectiveness of different pharmacological interventions used for pain in CYP with LLCs. SEARCH METHODS: The following electronic databases were searched up to December 2014: CENTRAL (in the Cochrane Library), MEDLINE, EMBASE, PsycINFO and CINAHL. In addition, we searched conference proceedings and reference lists of included studies. For completeness, we also contacted experts in the field. No language restrictions were applied. SELECTION CRITERIA: Randomised controlled trials (RCTs), quasi-randomised studies and other studies that included a clearly defined comparator group were included. The studies investigated pharmacological treatments for pain associated with LLCs in CYP. The treatment included those specifically developed to treat pain and those that acted as an adjuvant, where the treatment was not primarily developed to treat pain but has pain relieving properties. The LLC was identified by its inclusion in the Richard Hain Directory of LLCs. DATA COLLECTION AND ANALYSIS: Citations were screened by five review authors. Data were extracted by one review author and checked by a second. Two review authors assessed the risk of bias of included studies. A sufficient number of studies using homogeneous outcomes was not identified so a meta-analysis was not possible. MAIN RESULTS: We identified 24,704 citations from our database search. Nine trials with 379 participants fulfilled our inclusion criteria. Participants had cerebral palsy (CP) in five of the studies and osteogenesis imperfecta (OI) in the other four. Participants across the trials ranged in age from 2 to 19 years. All studies, apart from one cross-over trial, were parallel designed RCTs. Three of the trials on CP evaluated intrathecal baclofen (ITB) and two botulinum toxin A (BoNT-A). All of the OI trials evaluated the use of bisphosphonates (two alendronate and one pamidronate). No trials were identified that evaluated a commonly used analgesic in this patient group. Pain was a secondary outcome in five of the eight identified studies. Overall the quality of the trials was mixed. Only one study involved over 100 participants.For the two ITB studies for pain in CP, in the same study population but assessed at different time points in their disease, both found an effect on pain favouring the intervention compared to the control group (standard care or placebo) (mean difference (MD) 4.20, 95% confidence interval (CI) 2.15 to 6.25; MD 26.60, 95% CI 2.61 to 50.59, respectively). In these studies most of the adverse events related to the procedure or device for administration rather than the drug, such as swelling at the pump site. In one trial there were also eight serious adverse effects; these included difficulty swallowing and an epileptic seizure. The trial did not state if these occurred in the intervention group. At follow-up in both BoNT-A trials there was no evidence of a difference in pain between the trial arms among CP participants. The adverse events in the BoNT-A trials mostly involved those who received the intervention drug and involved seizures. Gastrointestinal problems were the most frequent adverse event in those who received alendronate. The trial investigating pamidronate found no evidence of a difference in pain compared to the control group. No adverse events were reported in this trial. AUTHORS' CONCLUSIONS: Published, controlled evidence on the pharmacological interventions for pain in CYP with LLCs is limited. The evidence that is currently available evaluated pain largely as a secondary outcome and the drugs used were all adjuvants and not always commonly used in general paediatric palliative care for pain. Based on current data this systematic review is unable to determine the effects of pharmacological interventions for pain for CYP with LLCs. Future trials with larger populations should examine the effects of the drugs commonly used as analgesics; with the rising prevalence of many LLCs this becomes more necessary.

Paediatric palliative medicine in the UK: past, present, future.

Like any new specialty, paediatric palliative medicine is facing challenges as it establishes itself. While many of the required core skills have their roots in adult palliative medicine, its practitioners come from a range of paediatric backgrounds that include oncology, community paediatrics, neurodisability and acute pain. Such heterogeneity has been invaluable in bringing together the diverse set of skills and competencies needed by children and families facing life-limiting illness. At the same time, it brings its own challenges in establishing consistent standards of clinical expertise, education and research--essential if children are to have access to the same degree of medical expertise in palliative care already available to most adults. This article traces the origins of palliative care in children, examines its current strengths and challenges, and considers how those might shape its future.

Paediatric palliative care: coming of age in oncology?

Palliative care in children has been emerging as a clinical subspecialty of paediatrics for many years. It requires the knowledge and experience of a paediatrician, combined with the skills of a palliative care specialist. Both are essential, as a paediatrician may not have advanced knowledge of palliative care and a palliative care specialist is unlikely to be familiar with the complexity of working with families where the child is the patient. This paper reviews recent literature and discusses advances in the development of palliative care services for children and young people with incurable cancer. It highlights key areas where paediatric palliative care differs from that of adults and outlines the barriers to providing palliation and conducting evidence-based research in children and young people dying from cancer.

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.