Clinical Trials: A Practical Approach

Objective: T o de v elop a North American Society for Pediatric Ga str oen te rol og y , He pat olo gy , and Nut ri tio n (N ASP GH AN) and Eu rop ea n Soc ie ty fo r Pe di atr ic Gas tr oen te ro log y , Hep at ol og y , and Nut rit io n (ES PGH AN ) int er nat io nal con se ns us on th e di agn os is an d ma nag em ent of gas tr oes op hag eal refl ux and gas tr oes op hag eal re flu x di sea se in th e ped ia tr ic po pu la tio n. Methods: An international panel of 9 pediatric gastroenterologists and 2 epidemiologists were selected by both societies, which de v eloped these guidelines based on the Delphi principle. Statements were based on systematic literature searches using the best-av ailable e vidence from PubMed, Cumulati ve Index to Nursing and Allied Health Literature, and bibliographies. The committee con v ened in face-to-face meetings 3 times. Consensus was achie v ed for all recommendations through nominal group technique, a structured, quantitati v e method. Articles were e v aluated using the Oxford Centre for Evidence-based Medicine Le vels of Evidence. Using the Oxford Grades of Recommendation, the quality of e vidence of each of the recommendations made by the committee was determined and is summarized in appendices. Results: More than 600 articles were re vie wed for this work. The document provides e vidence-based guidelines for the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population. Conclusions: Th is do cum ent is int end ed to be us ed in dai ly pra cti ce fo r th e de v el op me nt of fut ure cli ni cal pra ct ic e gu ide lin es and as a bas is for cli ni cal tr ia ls . JP GN 49 :49 8 – 54 7, 20 09 . Ke y Wo rd s: Cli nic al pra ct ic e gu id el ine s — Di agn os tic te sts — Ga str oes op hag ea l refl ux (GE R) — Ga str oes op hag ea l refl ux di sea se (GE RD ) — The rap eut ic mod al iti es. # 20 09 by Eu rop ea n Soc ie ty fo r Pe di atr ic Gas tr oen te ro log y , Hep at ol og y , and Nut rit io n and No rt h Am er ica n So ci ety for Pe dia tri c Ga str oen te rol og y , Hep at ol og y , an d Nu tr iti on

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Pediatric Gastroesophageal Reflux Clinical Practice Guidelines: Joint Recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN)

Growth and development can be investigated using readily observable demographic factors such as weight and age. Size is the primary covariate and can be referenced to a 70-kg person with allometry using a coefficient of 0.75 for clearance and 1 for volume. The use of these coefficients is supported by fractal geometric concepts and observations from diverse areas in biology. Fat free mass (FFM) might be expected to do better than total body weight when there are wide variations in fat affecting body composition. Clearance pathways develop in the fetus before birth. The use of postnatal age as a descriptor of maturation is unsatisfactory because birth may occur prematurely; therefore postmenstrual age is a superior predictor of elimination function. A sigmoid E(max) model (Hill equation) describes gradual maturation of clearance in early life leading to a mature adult clearance achieved at a later age.

Mechanism-Based Concepts of Size and Maturity in Pharmacokinetics

Although no randomized studies have demonstrated a positive impact of therapeutic drug monitoring (TDM) on clinical outcome in epilepsy, evidence from nonrandomized studies and everyday clinical experience does indicate that measuring serum concentrations of old and new generation antiepileptic drugs (AEDs) can have a valuable role in guiding patient management provided that concentrations are measured with a clear indication and are interpreted critically, taking into account the whole clinical context. Situations in which AED measurements are most likely to be of benefit include (1) when a person has attained the desired clinical outcome, to establish an individual therapeutic concentration which can be used at subsequent times to assess potential causes for a change in drug response; (2) as an aid in the diagnosis of clinical toxicity; (3) to assess compliance, particularly in patients with uncontrolled seizures or breakthrough seizures; (4) to guide dosage adjustment in situations associated with increased pharmacokinetic variability (e.g., children, the elderly, patients with associated diseases, drug formulation changes); (5) when a potentially important pharmacokinetic change is anticipated (e.g., in pregnancy, or when an interacting drug is added or removed); (6) to guide dose adjustments for AEDs with dose-dependent pharmacokinetics, particularly phenytoin.

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Antiepileptic drugs—best practice guidelines for therapeutic drug monitoring: A position paper by the subcommission on therapeutic drug monitoring, ILAE Commission on Therapeutic Strategies

Gastroesophageal reflux (GER), defined as passage of gastric contents into the esophagus, and GER disease (GERD), defined as symptoms or complications of GER, are common pediatric problems encountered by both primary and specialty medical providers. Clinical manifestations of GERD in children include vomiting, poor weight gain, dysphagia, abdominal or substernal pain, esophagitis and respiratory disorders. The GER Guideline Committee of the North American Society for Pediatric Gastroenterology and Nutrition has formulated a clinical practice guideline for the management of pediatric GER. The GER Guideline Committee, consisting of a primary care pediatrician, two clinical epidemiologists (who also practice primary care pediatrics) and five pediatric gastroenterologists, based its recommendations on an integration of a comprehensive and systematic review of the medical literature combined with expert opinion. Consensus was achieved through Nominal Group Technique, a structured quantitative method. The Committee examined the value of diagnostic tests and treatment modalities commonly used for the management of GERD, and how those interventions can be applied to clinical situations in the infant and older child. The guideline provides recommendations for management by the primary care provider, including evaluation, initial treatment, follow-up management and indications for consultation by a specialist. The guideline also provides recommendations for management by the pediatric gastroenterologist. This document represents the official recommendations of the North American Society for Pediatric Gastroenterology and Nutrition on the evaluation and treatment of gastroesophageal reflux in infants and children. The American Academy of Pediatrics has also endorsed these recommendations. The recommendations are summarized in a synopsis within the article. This review and recommendations are a general guideline and are not intended as a substitute for clinical judgment or as a protocol for the management of all patients with this problem.

Guidelines for evaluation and treatment of gastroesophageal reflux in infants and children: recommendations of the North American Society for Pediatric Gastroenterology and Nutrition.

Equivalent antipyretic activity of ibuprofen and paracetamol in febrile children

Caffeine acetylator phenotype was studied during maturation in 54 8− to 447-d-old children hospitalized for minor disease (group A) and in five 3− to 630-d-old children with Pierre Robin syndrome (group B). In group A, the children received 2.5 mg/kg caffeine orally once between birth and 15 mo. Group B patients were chronically treated with caffeine (2.3 to 15.8 mg/kg/d) for prevention of apneas, and the acetylator phenotype was serially determined. Phenotyping was performed on a spot urine sample collected 2–6 h after drug administration. Caffeine metabolites [5-acetylamino-6-formylamino-3-methyl uracil (AFMU), 1-methylxanthine, 1-methyluric acid, 1,7-methyluric acid, and 1,7-methylxanthine) were measured using HPLC. Acetylator phenotype was determined on the basis of AFMU/1-methylxanthine (ratio 1) and AFMU/AFMU + 1-methyluric acid + 1-methylxanthine + 1,7-methylxanthine + 1,7-methyluric acid (ratio 2) molar ratios. In group A, all children were slow acetylators before 83 d of age (ratio 1 < 0.4; ratio 2 < 0.08), whereas older children included slow and fast acetylators. The acetylation molar ratios differed significantly between age groups and increased with age. The cumulative percentage of fast acetylators increased with age but the plateau was not yet reached at 15 mo. In three children, the phenotyping was repeated after 15 mo: the second determination was consistent with the first one. In group B, all children appeared as slow acetylators on the first phenotyping. Four of them appeared subsequently as fast acetylators; one remained a slow acetylator until 11 mo. These results suggest that maturation of caffeine acetylation occurs during at least the first 15 mo of life for fast acetylators but is not detectable in slow acetylators. Acetylator status cannot reliably be determined before at least 15 mo.

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Caffeine Acetylator Phenotyping during Maturation in Infants

Isoniazid acetylation metabolic ratio (MR) was studied in 61 children with tuberculosis after administration of isoniazid. MR was calculated as the molar acetylisoniazid to isoniazid concentration ratio. MR was used as a probe for N-acetyltransferase activity and to determine the acetylation phenotype. MR had a bimodal distribution with an antimode between 0.48 and 0.77. MR and the percentage of fast acetylators increased significantly with age. The cumulative frequency of fast acetylators increased with age, with a plateau reached around 4 years. MR value was checked during treatment in 44 children. All children but one who initially appeared as fast acetylators remained in this group after repeated testing. Among the 30 slow acetylators, 12 became fast acetylators, and 10 showed a variable phenotyping at different ages. A bimodal distribution of the isoniazid acetylation MR was shown in children, with an antimode close to that described in the literature and a maturation of isoniazid acetylation during the first 4 years.

Isoniazid acetylation metabolic ratio during maturation in children.

Objective

We investigated the pharmacokinetics, pharmacodynamics, and tolerability of lansoprazole in children after single and multiple administrations.



Methods

Forty children (age range, 18 days-14 years) with gastric acid-related disorders entered an open study and received lansoprazole in a single dose of 17 mg · m−2 (group A) or in multiple doses (17 mg · m−2 per day) for 7 to 14 days (group B). Lansoprazole plasma concentrations were measured by HPLC. A 24-hour intragastric pH monitoring assessed the antisecretory effect.



Results

In group A, maximal concentration (Cmax) was 1023 ± 775 (mg · L−1)/(17 mg · m−2), time to reach Cmax was 1.8 ± 0.8 hours, elimination half-life was 1.5 ± 2.0 hours, area under the concentration-time curve from time zero to infinity [AUC(0-∞)] was 3503 ± 6025 (mg · L−1 · h)/(17 mg · m−2), apparent plasma clearance was 0.57 ± 0.47 L · h−1 · kg−1, and apparent volume of distribution was 0.61 ± 0.36 L · kg−1. In group B, Cmax was 750 ± 511 (mg · L−1)/(17 mg · m−2), time to reach Cmax was 1.8 ± 1.1 hours, elimination half-life was 1.2 ± 1.1 hours, AUC(0-∞) was 2351 ± 3691 (mg · L−1 · h)/(17 mg · m−2), apparent plasma clearance was 0.71 ± 0.50 L · h−1 · kg−1, and apparent volume of distribution was 0.9 ± 0.7 L · kg−1. No influence of age was shown on pharmacokinetic parameters in both groups. However, data suggested that elimination was reduced in neonates and higher in infants than in adults. The values for 24-hour percentage of time at gastric pH <4 and pH <3 were 61% ± 21% and 51% ± 21% (group A) and 47% ± 24% and 37% ± 21% (group B), respectively. In both groups the antisecretory effect decreased with age, and in group A it was positively correlated to Cmax and AUC(0-∞). The mean gastrin serum concentration significantly increased (+31%) after 12.6 ± 1.5 days of treatment.



Conclusions

Lansoprazole was well tolerated in children. After a single oral dose of 30 mg per 1.73 m2, there was a trend for the elimination to be higher in infants than in adults and the antisecretory effect appeared to be higher in infants younger than 6 months than in older children and adults.



Clinical Pharmacology & Therapeutics (2002) 71, 359–367; doi: 10.1067/mcp.2002.122472

Pharmacokinetic‐pharmacodynamic study of oral lansoprazole in children

1. Lamotrigine is a new antiepileptic drug, chemically unrelated to currently used antiepileptic medication. Its pharmacokinetics can be influenced by concomitant antiepileptic medication. 2. This study was performed to assess the pharmacokinetic profile of lamotrigine in three groups of children treated with different types of comedication: drugs known to induce, to inhibit or to have no clinically significant influence on drug metabolism, respectively. 3. Thirty-one children aged 6 months to 5 years were included and received a 2 mg kg-1 single oral dose. Lamotrigine plasma profiles were different between the three comedication groups. The half-lives (mean +/- s.d.) were: 7.7 +/- 1.8 h, 21.9 +/- 6.8 h, 44.7 +/- 10.2 h in the "inducer', "other' and "inhibitor' groups respectively. 4. Patients were then dosed to steady state, with the dosage adjusted on the basis of the single dose pharmacokinetics to achieve a minimum plasma concentration between 1.5 and 3 mg l-1. The mean minimum plasma concentration for the three groups was 2.54 +/- 1.28 mg l-1 at steady state. 5. Dosage of lamotrigine can be optimised with knowledge of the metabolic effects of antiepileptic comedication.

A. Pariente-Khayat

Papers

Equivalent antipyretic activity of ibuprofen and paracetamol in febrile children

Caffeine Acetylator Phenotyping during Maturation in Infants

Isoniazid acetylation metabolic ratio during maturation in children.

Pharmacokinetic‐pharmacodynamic study of oral lansoprazole in children

Influence of concurrent antiepileptic medication on the pharmacokinetics of lamotrigine as add‐on therapy in epileptic children