This model was validated using haloperidol, which antagonized the acute effects of apomorphine.107 The ketamine model N-Methyl-D-aspartate (NMDA) receptor blockade by ketamine infusion in HVs is acknowledged to be a good model of schizophrenia, reproducing positive, negative, and cognitive symptoms.55-65 Despite

evidence that ketamine modulates dopamine striatal concentration,108-111 its clinical effects were not reversed by haloperidol in patients112 or in Inhibitors,research,lifescience,medical HVs,61 or olanzapine,113 but were blunted by clozapine in patients with schizophrenia.114 This inconsistent effect of antipsychotics could be dose-related. The above studies used ketamine doses of 0.1 to 0.9 mg/kg in bolus or 1-h infusion, whereas we use 0.16 to 0.54 mg/kg in a 2-h infusion. Conclusion There is an agreement on the need to increase the efficiency of drug development. Inhibitors,research,lifescience,medical Whatever the improvements in the chemical and preclinical steps, clinical development strategy remains critical. Human models in HVs are obviously not a panacea. They are not applicable to any situation and the validity of the different

provocation procedures is uneven. Their optimal use is within what we call an “enhanced development plan,” which requires improvements in safety data processing. Nevertheless, when properly used, human models can secure phase 1 study results, be of help in a “go” (more than in a Inhibitors,research,lifescience,medical “no-go”) decision, and therefore improve the safety and efficiency of patient studies, leading to a reduction Inhibitors,research,lifescience,medical in both time and resources. Selected abbreviations and

acronyms AD Alzheimer’s disease BZD benzodiazepine DB double-blind (study) fMRI functional magnetic resonance imaging HV healthy volunteer MTD maximal tolerated dose PD pharmacodynamics PK pharmacokinetics POC proof of concept
Pharmaceutical regulatory change is driven by a number of factors, one of the most influential being the harmonization process lead by the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). (Detailed information Inhibitors,research,lifescience,medical and guidelines are available on the ICH homepage.1) The ICH is essentially composed through of six parties: the three major regulatory authorities of the USA, Europe, and Japan, and the three corresponding associations of pharmaceutical manufacturers. It would seem natural that the guidelines produced by the ICH are international in scope and purpose. The ICH produces “soft law” Abiraterone regulations that are by definition not legally binding. An ICH guideline has no more binding power than a resolution of the General Assembly of the United Nations. Once adopted by a country, they may become as binding as law (for example, the new Japanese good clinical practice [GCP] guidelines). As with resolutions, guidelines are adopted in a consensual way and reflect the minimum status of agreement on any topic.