The use of intranasal sufentanil and/or s-ketamine for treatment of procedural pain in children in an ambulatory setting: A retrospective observational study.

BACKGROUND: Minor but painful medical procedures are often handled at the operating room. If safe and effective treatment options are available many procedures may be performed outside of the operating room. OBJECTIVE(S): The objective of this study is to assess the adverse events of intranasal s-ketamine and/or sufentanil alone or as part of a multimodal analgesic regime for medical procedures outside of the operating room. Secondary outcomes included analgesic effect, doses and indications for use. DESIGN: Retrospective observational study. SETTING: Tertiary care paediatric hospital. PATIENTS: Children 1 year up till 18 years. INTERVENTION(S): Intranasal (IN) sufentanil (S), intranasal s-ketamine (K) or the free combination of the two drugs (SK). MAIN OUTCOME MEASURE(S): The frequency of adverse events including serious adverse events reported by intervention. RESULTS: Between 2004 and 2014, 2185 medical procedures were registered, including 652 procedures with IN SK, 1469 procedures with IN S and 64 procedures with IN K. The children's median age was 5.6 years (range 1.0-17.9). Medical procedures with at least one adverse event were 18% with IN SK, 25% with IN K and 18% with IN S. Common adverse events included episodes of vomiting (9%), nausea (8%) and dizziness (3%). In two patients receiving IN S, serious adverse events occurred. One patient had respiratory depression and bronchospasm and another patient with cerebral palsy had a seizure. Both were handled immediately and did not result in any sequelae. The median doses of intranasal sufentanil were 38% lower when combined with s-ketamine (IN SK free combination: sufentanil dose 0.5 µg/kg (range 0.2-1.3) and s-ketamine dose 0.5 mg/kg (range 0.2-1.5). IN S monotherapy, sufentanil dose 0.8 µg/kg (range 0.2-2.7)). Similar analgesic effect was reported for S and SK. CONCLUSIONS: Intranasal sufentanil and/or s-ketamine are feasible for the treatment of procedural pain in an ambulatory setting with appropriate per- and post-procedural observations and trained staff.

Pharmacokinetics of an intravenous bolus dose of clonidine in children undergoing surgery.

BACKGROUND: Clonidine is used off-label in children but only limited pediatric pharmacokinetic data are available for intravenously administered clonidine. OBJECTIVES: To determine pharmacokinetic parameter estimates of clonidine in healthy children undergoing surgery and to investigate age-related differences. Furthermore, to investigate possible pharmacokinetic differences of clonidine between this group of children and a cohort with cardiac diseases. METHODS: In a randomized placebo-controlled trial (The PREVENT AGITATION trial), blood samples for clonidine pharmacokinetic analysis were collected in a proportion of the enrolled patients. Healthy children with ASA score 1-2 in the age-groups 1 to <2 years and 2-5 years were randomized for blood sampling. Clonidine was administered as a single intravenous bolus of 3 µg/kg intraoperatively. Blood samples were drawn at baseline, 5, 10, 15, 30, 60 minutes after dosing and additionally every hour until discharge from the PACU. Clonidine analysis was performed on liquid chromatography-mass spectrometry. RESULTS: Data form eighteen children were available for pharmacokinetic analysis (ASA I; male/female: 17/1; age: 1-5 years; weight 8.7-24 kg). Population parameter estimates for the 2-compartment model were similar to previous published data for children who underwent cardiac surgery. A pooled analysis including data from 59 children indicated clearance of 14.4 L h-1  70 kg-1 and volume of distribution of 192.6 L 70 kg-1 . No age-related pharmacokinetic differences and no difference in time from administration of study medication to awakening were found. Children 1 to <2 years had a shorter PACU stay than children 2-5 years (mean difference 17% 95% CI:3%-34%, P = .02). CONCLUSION: Pharmacokinetic parameter estimates were similar for children undergoing general surgery and cardiac surgery given a single dose of intravenous clonidine. These results indicated that no dose reduction is needed in children aged 1 to <2 years compared with those 2-5 years, which was supported by pharmacodynamic observations.

Intranasal sufentanil/ketamine analgesia in children.

BACKGROUND: The management of procedural pain in children ranges from physical restraint to pharmacological interventions. Pediatric formulations that permit accurate dosing, are accepted by children and a have a rapid onset of analgesia are lacking. OBJECTIVES: To investigate a pediatric formulation of intranasal sufentanil 0.5 mcg·kg(-1) and ketamine 0.5 mg·kg(-1) for procedural pain and to characterize the pharmacokinetic (PK) profile. METHODS: Fifty children (≥10 kg) scheduled for a painful procedure were included in this prospective nonrandomized open-label clinical trial. Thirteen of these children had central venous access for drug assay sampling; enabling a compartmental PK analysis using nonlinear mixed-effects models. Pain intensity before and during the procedure was measured using age-appropriate pain scales. Heart rate, oxygen saturation and sedation were recorded. RESULTS: Children had a mean age of 8.8 (sd 4.9) years and weight 35.2 (sd 20.1) kg. Sufentanil/ketamine nasal spray was effective (procedural pain intensity scores ≤5 (0-10)) in 78% of the painful procedures. The spray was well accepted by 94% of the children. Oxygen saturation and heart rate remained stable, and sedation was minimal. The bioavailability of sufentanil and ketamine was 24.6% and 35.8%, respectively. Maximum plasma concentration (Cmax) of sufentanil was 0.042 mcg·l(-1) (coefficient of variation (CV) 12.9%) at 13.8 min (CV 12.4%) (Tmax). Cmax for ketamine was 0.102 mg·l(-1) (CV 10.8%), and Tmax was 8.5 min (CV 17.3%). CONCLUSION: Sufentanil/ketamine nasal spray provided rapid onset of analgesia for a variety of painful procedures with few adverse effects and has promising features for use in pediatric procedural pain management.

Topical morphine for oral mucositis in children: dose finding and absorption.

CONTEXT: Systemic opioids for painful chemotherapy-induced oral mucositis in children often result in unsatisfactory pain relief and a high frequency of side effects. Opioids applied topically can produce analgesia by binding to opioid receptors on peripheral terminals of sensory neurons. These receptors are upregulated during inflammation, for example, in oral mucositis. OBJECTIVES: The aims of this study were to investigate the dose-response relationship (n=7) and the potential absorption of topical morphine (n=5) across oral mucosa in children with oral mucositis. METHODS: The dose-response study was conducted according to a sequential study design (Dixon's Up-and-Down method) for topical morphine doses of 0.025-0.400mg/kg, with the decrease in oral pain score as the primary outcome. To assess potential absorption across oral mucosa after a single dose of topical morphine of 0.050mg/kg, blood samples were drawn and the plasma concentrations of morphine and metabolites were determined by high-pressure liquid chromatography. RESULTS: A decrease in oral pain score of ≥36% was achieved in six of seven patients in the dose-response part of the study. Plasma concentrations of morphine and metabolites were well below effective analgesic levels. CONCLUSION: No obvious dose-response effect was found for topical morphine doses of 0.025-0.400mg/kg, and topically applied morphine was not absorbed in clinically relevant doses. However, this study was limited by the small number of patients and the allowance of a systemic opioid as rescue medication. Thus, randomized controlled studies are needed to further investigate the analgesic properties of topical morphine.

Population pharmacokinetics of buprenorphine following a two-stage intravenous infusion in healthy volunteers.

OBJECTIVE: The aim of this investigation was to characterize the pharmacokinetics of buprenorphine following administration of an intravenous (i.v.) infusion. To date, the population kinetics of buprenorphine has been described for bolus administration only. METHODS: Twenty-three healthy male volunteers aged 21-40 years received 0.6 mg buprenorphine by means of an i.v. infusion over a 150-min period. The plasma concentration-time profiles up to 24 h post-administration of the infusion were subjected to population pharmacokinetic modelling using NONMEM: software. RESULTS: A three-compartment model best described the plasma concentration-time course. Body weight was found to be a significant covariate for elimination clearance in a linear fashion. Inter-individual variability (coefficient of variation) was estimable for apparent clearance (CL, 23.5%), central distribution volume (V(1), 81.8%), peripheral distribution volume 1 (V(2), 23.7%) and inter-compartmental clearances between V(1) and V(2) (Q(2), 34.8%). Models using parameters derived from previous published data obtained after an i.v. bolus of buprenorphine were found to overestimate the measured buprenorphine concentrations during the course of the i.v. infusion and to underpredict those following the end of the infusion. CONCLUSION: Most parameters describing the disposition of buprenorphine in the volunteers showed only moderate inter-subject variability. However, the parameters differed from those previously reported for i.v. bolus administration. We conclude that pharmacokinetic parameter estimates obtained from the appropriate study in accordance to the mode of administration should be used in the design of dose regimens of buprenorphine.