The majority of critically ill children admitted to Paediatric Intensive Care Units (PICU) will require sedation and analgesia which is commonly achieved with a combination of an benzodiazepine and an opioid. However, these agents have a significant side-effect profile, including tolerance, withdrawal and respiratory/circulatory depression. Clonidine is commonly used for sedation in PICU and recommended by guidelines in various countries although there is a lack of evidence regarding it safety and efficacy in this setting. The need for safety and efficacy data as well as an age appropriate formulation for clonidine has been realised and clonidine is included in the EMA “Revised Priority List for Studies into Off-patent Medicinal Products”. Thus this proposal addresses an important paediatric therapeutic need. It is designed to fullfill the requirements for most ethical research in the paediatric population considering risk minimisation for patients, avoiding unnecessary studies and make use of already available data as outlined in the Paediatric Regulation (EC) No 1901/2006. The objectives of this project are a) to develop an age appropriate formulation of clonidine suitable for sedation of children in PICU b) to conduct a randomised, phase III, double-blind, active-controlled parallel group clinical trial of clonidine vs midazolam in patients from birth to 18 years to establish the efficacy and safety, including long-term outcomes and dose-dependent effects of clonidine and c) to establish an European consensus guideline for sedion of critically ill children. The ultimate goal is to use these data and to apply for a PUMA. On this basis a Paediatric Investigation Plan (PIP) has been approved by the EMA in February 2013 and is reflected in the work plan of CloSed. The project will increase the availability of paediatric medicines, foster the conduct of clinical trials in children and establish international paediatric research collaborations.