Authors' Reply to Coste et al.: "Levothyrox® New and Old Formulations: Are they Switchable for Millions of Patients?"

"Authors'Reply to Coste et al"International audienc

A comprehensive review on non-clinical methods to study transfer of medication into breast milk – A contribution from the ConcePTION project

open17siBreastfeeding plays a major role in the health and wellbeing of mother and infant. However, information on the safety of maternal medication during breastfeeding is lacking for most medications. This leads to discontinuation of either breastfeeding or maternal therapy, although many medications are likely to be safe. Since human lactation studies are costly and challenging, validated non-clinical methods would offer an attractive alternative. This review gives an extensive overview of the non-clinical methods (in vitro, in vivo and in silico) to study the transfer of maternal medication into the human breast milk, and subsequent neonatal systemic exposure. Several in vitro models are available, but model characterization, including quantitative medication transport data across the in vitro blood-milk barrier, remains rather limited. Furthermore, animal in vivo models have been used successfully in the past. However, these models don't always mimic human physiology due to species-specific differences. Several efforts have been made to predict medication transfer into the milk based on physicochemical characteristics. However, the role of transporter proteins and several physiological factors (e.g., variable milk lipid content) are not accounted for by these methods. Physiologically-based pharmacokinetic (PBPK) modelling offers a mechanism-oriented strategy with bio-relevance. Recently, lactation PBPK models have been reported for some medications, showing at least the feasibility and value of PBPK modelling to predict transfer of medication into the human milk. However, reliable data as input for PBPK models is often missing. The iterative development of in vitro, animal in vivo and PBPK modelling methods seems to be a promising approach. Human in vitro models will deliver essential data on the transepithelial transport of medication, whereas the combination of animal in vitro and in vivo methods will deliver information to establish accurate in vitro/in vivo extrapolation (IVIVE) algorithms and mechanistic insights. Such a non-clinical platform will be developed and thoroughly evaluated by the Innovative Medicines Initiative ConcePTION.openNauwelaerts N.; Deferm N.; Smits A.; Bernardini C.; Lammens B.; Gandia P.; Panchaud A.; Nordeng H.; Bacci M.L.; Forni M.; Ventrella D.; Van Calsteren K.; DeLise A.; Huys I.; Bouisset-Leonard M.; Allegaert K.; Annaert P.Nauwelaerts N.; Deferm N.; Smits A.; Bernardini C.; Lammens B.; Gandia P.; Panchaud A.; Nordeng H.; Bacci M.L.; Forni M.; Ventrella D.; Van Calsteren K.; DeLise A.; Huys I.; Bouisset-Leonard M.; Allegaert K.; Annaert P

Infant exposure to Fluvoxamine through placenta and human milk: a case series - A contribution from the ConcePTION project [case report].

INTRODUCTION Fluvoxamine is widely used to treat depression during pregnancy and lactation. However, limited data are available on its transfer to the fetus or in human milk. This case series provides additional information on the infant exposure to fluvoxamine during pregnancy and lactation. CASE PRESENTATION Two women, aged 38 and 34 years, diagnosed with depression were treated with 50 mg fluvoxamine during pregnancy and lactation. At delivery a paired maternal and cord blood sample was collected for each woman. The first mother exclusively breastfed her child for 4 months and gave one foremilk and one hindmilk sample at 2 days and 4 weeks post-partum, whereas the second mother did not breastfeed. RESULTS The cord to plasma concentration ratios were 0.62 and 0.48, respectively. At 2 weeks post-partum, relative infant doses (RID) were 0.47 and 0.57% based on fluvoxamine concentrations in foremilk and hindmilk, respectively. At 4 weeks post-partum, the RIDs were 0.35 and 0.90%, respectively. The child from the first mother was born healthy and showed a normal development at the 6th, 18th and 36th month follow-ups. One of the twins from the second woman was hospitalized for hypoglycemia that was attributed to gestational diabetes and low birth weight. The second one was born healthy. CONCLUSION These results suggest a minimal exposure to fluvoxamine during lactation which is in accordance with previously published data. Larger clinical and pharmacokinetic studies assessing the long-term safety of this drug during lactation and the variability of its exposure through breastmilk are warranted

Why Were More Than 200 Subjects Required to Demonstrate the Bioequivalence of a New Formulation of Levothyroxine with an Old One?

At the request of French Regulatory Authorities, a new formulation of Levothyrox® was licensed in France in 2017, with the objective of avoiding the stability deficiencies of an existing licensed formulation. Before launching the new formulation, an average bioequivalence (ABE) trial was conducted, having enrolled 204 subjects and selected for interpretation a narrow a priori bioequivalence range of 0.90–1.11. Bioequivalence was concluded. In a previous publication, we questioned the ability of an ABE trial to guarantee the switchability within patients of the new and old levothyroxine formulations. It was suggested that the two formulations should be compared using the conceptual framework of individual bioequivalence. The present paper is a response to those claiming that, despite the fact that ABE analysis does not formally address the switchability of the two formulations, future patients will nevertheless be fully protected. The basis for this claim is that the ABE study was established in a large trial and analyzed using a stringent a priori acceptance interval of equivalence. These claims are questionable, because the use of a very large number of subjects nullifies the implicit precautionary intention of the European guideline when, for a Narrow Therapeutic Index drug, it recommends shortening the a priori acceptance interval from 0.80–1.25 to 0.90–1.11

Levothyrox® new and old formulations: are they switchable for millions of patients?

International audienceIn France, more than 2.5 million patients are currently treated with levothyroxine, mainly as the marketed product Levothyrox ®. In March 2017, at the request of French authorities, a new formulation of Levothyrox ® was licensed, with the objective of avoiding stability deficiencies of the old formulation. Before launching this new formulation, an average bioequivalence trial, based on European Union recommended guidelines, was performed. The implicit rationale was the assumption that the two products, being bioequivalent, would also be switchable, allowing substitution of the new for the old formulation, thus avoiding the need for individual calibration of the dosage regimen of thyroxine, using the thyroid-stimulating hormone level as the endpoint, as required for a new patient on initiating treatment. Despite the fact that both formulations were shown to be bioequivalent, adverse drug reactions were reported in several thousands of patients after taking the new formulation. In this opinion paper, we report that more than 50% of healthy volunteers enrolled in a successful regulatory average bioequivalence trial were actually outside the a priori bioequivalence range. Therefore, we question the ability of an average bioequivalence trial to guarantee the switchability within patients of the new and old levothyroxine formulations. We further propose an analysis of this problem using the conceptual framework of individual bioequivalence. This involves investigating the bioavailability of the two formulations within a subject, by comparing not only the population means (as established by average bioequivalence) but also by assessing two variance terms, namely the within-subject variance and the variance estimating subject-by-formulation interaction. A higher within individual variability for the new formulation would lead to reconsideration of the appropriateness of the new formulation. Alternatively, a possible subject-by-formulation interaction would allow a judgement on the ability, or not, of doctors to manage patients effectively during transition from the old to the new formulation

A comprehensive review on non-clinical methods to study transfer of medication into breast milk – A contribution from the ConcePTION project

Breastfeeding plays a major role in the health and wellbeing of mother and infant. However, information on the safety of maternal medication during breastfeeding is lacking for most medications. This leads to discontinuation of either breastfeeding or maternal therapy, although many medications are likely to be safe. Since human lactation studies are costly and challenging, validated non-clinical methods would offer an attractive alternative. This review gives an extensive overview of the non-clinical methods (in vitro, in vivo and in silico) to study the transfer of maternal medication into the human breast milk, and subsequent neonatal systemic exposure. Several in vitro models are available, but model characterization, including quantitative medication transport data across the in vitro blood-milk barrier, remains rather limited. Furthermore, animal in vivo models have been used successfully in the past. However, these models don't always mimic human physiology due to species-specific differences. Several efforts have been made to predict medication transfer into the milk based on physicochemical characteristics. However, the role of transporter proteins and several physiological factors (e.g., variable milk lipid content) are not accounted for by these methods. Physiologically-based pharmacokinetic (PBPK) modelling offers a mechanism-oriented strategy with bio-relevance. Recently, lactation PBPK models have been reported for some medications, showing at least the feasibility and value of PBP

Coliques du nourrisson et conseils à l'officine

Les coliques du nourrisson sont un trouble courant chez les nouveaux-nés en bonne santé avant les 4 premiers mois de vie. Il s'agit de crises de pleurs de plus de 3 heures par jour, plus de 3 jours par semaine et durant plus de 3 semaines. Les étiologies ne sont pas clairement définies : intolérance alimentaire, immaturité de la fonction intestinale, troubles de la motilité, anxiété des parents et tempérament de l'enfant. Des hypothèses récentes évoquent le rôle de la flore intestinale. A ce jour, dans la pratique officinale, il n'y a pas de consensus établi pour leur prise en charge. Le but de ce travail a consisté à faire un bilan des connaissances des parents se présentant à l'officine à ce sujet. Les résultats indiquent que les principaux axes de prise en charge sont les méthodes comportementales et la diététique avec notamment un apport en probiotiques. Une prise en charge globale semble efficace. A l'issue de ce travail, nous avons réalisé une fiche conseil destinée aux parents.TOULOUSE3-BU Santé-Centrale (315552105) / SudocSudocFranceF

Influence de la microgravité simulée sur la pharmacocinétique du paracétamol utilisé comme marqueur de la vidange gastrique (étude chez le rat et chez le volontaire sain)

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Influence de la microgravité simulée sur la pharmacocinétique du paracétamol (étude chez le rat)

TOULOUSE3-BU Santé-Centrale (315552105) / SudocTOULOUSE3-BU Santé-Allées (315552109) / SudocPARIS12-CRETEIL BU Eco. Gestion (940282103) / SudocSudocFranceF

Etude des facteurs de l'absorption orale du Topotécan à l'aide du modèle du sac d'intestin éversé de rat et de porc

Topotecan, a molecule belonging to the family of topoisomerase I inhibitors, is used as the second-line treatment of ovarian cancer metastases. We examined some factors influencing the variability of the trans-intestinal passage of topotecan using the in vitro model, the everted intestinal sac, in rats and pigs. Topotecan was assayed using a LC-MS. A linear uptake was found for concentrations up to 6 g/mL. The study of competitive inhibitors and pH did not significantly increase the intestinal absorption, due to interferences problems it was not possible to interpret. An interaction between topotecan and ondansetron showed an increase in the trans-intestinal passage, however the use of a new assay method did not confirm these result. A study of the interaction ondansetron-topotecan in vivo on animals and humans could be interesting to compare with our results.TOULOUSE3-BU Santé-Centrale (315552105) / SudocSudocFranceF