Use of amlodipine oral solution for the treatment of hypertension in children.

Background Amlodipine is a widely used antihypertensive agent for the treatment of paediatric hypertension, but the commercially available tablets are not suitable to treat young patients, who need lower, flexible dosages and a liquid formulation. Objective To determine the pharmacokinetic properties of amlodipine and the acceptability of a standardised, extemporaneous oral solution. Method A newly developed liquid formulation of amlodipine was administered to hypertensive children between the age of 6 months and 11 years. Using a limited sampling strategy, population PK analysis was performed using nonlinear mixed effects modelling. Results Nine children, with a median age of 2.9 years (IQR 1.8-8.4), receiving stable amlodipine therapy in a median dose of 0.15 mg kg-1 day-1 (IQR 0.11-0.18), were switched to study medication. The population pharmacokinetic model was able to accurately predict the clearance of amlodipine in the study population. Based on the final model, clearance was reduced by 31.2% (RSE: 10%) in females. Patient reported outcomes on taste from a five-point hedonic scale were available for five patients, who scored the taste from positive to slightly negative. Conclusion The results from the PK study and the acceptability assessment show that the amlodipine oral solution presented in this study offers an appropriate treatment option for young children.

Potential prediction of formulation performance in paediatric patients using biopharmaceutical tools and simulation of clinically relevant administration scenarios of nifedipine and lorazepam.

AIMS: This study explores the impact of paediatric patient related factors and choice of formulation on the dissolution characteristics of nifedipine and lorazepam, 2 drug substances regularly applied in very young patients and in compounded formulations. METHODS: Dissolution experiments were designed to reflect clinical practice in a paediatric hospital, with respect to dosage forms, feeding regimens and methods of administration. Solubility studies addressed the influence of age and prandial state. Drug solubility and dissolution experiments were conducted in biorelevant media and adapted age-specific (neonate and infant) media. Dissolution studies were performed with the mini-paddle apparatus and the flow-through cell apparatus. RESULTS: Dissolution of nifedipine formulations was not affected by age-related changes of the fasted state simulated gastrointestinal fluids, and by disintegration of the formulation before administration. However, a significant difference in nifedipine's dissolution rate from commercial tablets and compounded capsules was observed. The dissolution of lorazepam tablets was affected by fasted- vs fed-state media, but it was deemed less likely to be clinically relevant. The significant effect of fed-state media on nifedipine's solubility was considered to have possible clinical relevance since very young patients are almost continuously in a fed state. CONCLUSION: The in vitro results obtained from these studies reveal the potential of biorelevant solubility and dissolution studies reflecting clinical practice to predict drug performance in paediatric patients.

Manipulation of oral medication for children by parents and nurses occurs frequently and is often not supported by instructions.

AIM: Due to a lack of age-appropriate formulations, administration of drugs to children remains a challenge. This study aimed to identify the problems experienced in both the outpatient setting and the clinical setting. METHODS: Between June 2017 and January 2018, we performed a cross-sectional, prospective study at the Sophia Children's Hospital, The Netherlands. The study comprised of a structured interview on drug manipulations with parents visiting the outpatient clinic, and an observational study of drug manipulations by nurses at the wards. RESULTS: A total of 201 questionnaires were collected, accounting for 571 drugs and 169 manipulations (30%). Drug substances that were most often mentioned as manipulated were macrogol (n = 23), esomeprazole (n = 15), paracetamol (n = 8), methylphenidate (n = 7) and melatonin (n = 7). Of all manipulated medicines, 93/169 (55%) were manipulated according to the instructions or recommendations of the Summary of Product Characteristics (SmPC) or patient information leaflet. During the observational study, manipulation was performed by 21/35 of observed nurses (60%), of whom 11 deviated from the hospital protocol for manipulation or SmPC (52%). CONCLUSION: Manipulation was a widely used method to administer drugs to children. Validated information regarding manipulation of drugs for both parents and nursing staff is needed.

Oral lorazepam can be substituted for intravenous midazolam when weaning paediatric intensive care patients off sedation.

AIM: Intravenous sedatives used in the paediatric intensive care unit (PICU) need to be tapered after prolonged use to prevent iatrogenic withdrawal syndrome (IWS). We evaluated the occurrence of IWS and the levels of sedation before and after conversion from intravenous midazolam to oral lorazepam. METHODS: This was a retrospective, observational, single cohort study of children under the age of 18 admitted to the PICU of the Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands, between January 2013 and December 2014. The outcome parameters were the Sophia Observation withdrawal Symptoms (SOS) scale scores and COMFORT Behaviour scale scores before and after conversion. RESULTS: Of the 79 patients who were weaned, 32 and 39 had before and after SOS scores and 77 had COMFORT-B scores. IWS was reported in 15 of 79 patients (19.0%) during the 48 hours before the start of lorazepam and 17 of 79 patients (21.5%) during the 48 hours after treatment started. Oversedation was seen in 16 of 79 patients (20.3%) during the 24 hours before substitution and in 30 of 79 patients (38.0%) during the 24 hours after substitution. CONCLUSION: The weaning protocol was not able to prevent IWS in all patients, but converting from intravenous midazolam to oral lorazepam did not increase the incidence.

Bioequivalence study of an extemporaneously prepared oral solution of amlodipine suitable for use in pediatric patients compared to commercial tablets.

OBJECTIVE: Amlodipine, a long-acting dihydropyridine calcium channel blocker, is frequently prescribed to pediatric patients. To date, no suitable pediatric formulation has been available. In this study, an amlodipine oral solution was developed and tested for bioequivalence to tablets in healthy adult volunteers. METHODS: This study was designed as an open-label, single-dose, twosequence, two-period, crossover trial to assess the bioequivalence of a newly developed amlodipine besylate oral solution 0.5 mg/mL compared to Norvasc® 5 mg tablets. 13 adult subjects (mean [standard deviation] age of 23.2 [3.6] years, weight 71.5 [7.7] kg) were included and blood samples were collected for 72 hours. Amlodipine plasma levels were determined using a validated UPLC-MS/MS assay. Non-compartmental pharmacokinetic parameters were compared between the formulations according to European Medicines Agency (EMA) bioequivalence guidelines. RESULTS: The 90% confidence intervals of the test/reference ratios of the geometric means for the primary pharmacokinetic parameters AUC(0-72) (88.24 - 104.37%) and C(max) (99.00 - 121.40%) were within the acceptance range of 80.00 - 125.00% for bioequivalence. Mean (SD) AUC(0-72) was 102.7 (26.8) (26.8) µg × h/L for the solution and 108.2 (30.6) µg × h/L for the tablet. Mean (SD) Cmax of the solution was 3.11(1.06) µg/L with a median (IQR) t(max) of 4.0 (2.6 - 7.5) hours. Mean (SD) C(max) of the tablet was 2.91 (0.84) µg/L with a median (IQR) tmax of 6.0 (4.0 - 14.0) hours. Intrasubject coefficients of variation were 10.2% (AUC(0-72)) and 12.4% (C(max)). CONCLUSIONS: The formulations are bioequivalent according to EMA guidelines. This warrants further study of our novel amlodipine oral solution in pediatric patients.