Published online by Cambridge University Press: 22 March 2010
Key words: Schizophrenia; clinical trial; osanetrant; NK3 antagonist; 5-HT2A/C antagonist; central cannabinoid antagonist; neurotensin antagonist.
Introduction
Schizophrenia is one of the most common and severe forms of mental illness. Its major features include psychosis, cognitive impairment, negative symptoms, and a high rate of suicide, the latter mainly due to depression and hopelessness. The treatment of schizophrenia in much of the world is largely pharmacologic, with psychosocial support and cognitive rehabilitation quite useful, but often not provided because of cost. Prior to the reintroduction of clozapine in 1990 in the USA, the major pharmacologic treatment for schizophrenia was dopamine D2 receptor blockers, such as haloperidol, whose chief side-effects were mechanism-based blockade of D2 receptors in the dorsal striatum, leading to a variety of acute and chronic extrapyramidal side-effects (EPS) (e.g. tardive dyskinesia). The demonstration that clozapine was more efficacious in a subgroup of patients and produced fewer EPS of all types (Meltzer, 1997; Kane et al., 1988), led to search for other drugs which were clozapine like but did not produce agranulocytosis, the side-effect which limited clozapine to use in treatment-resistant patients. The ensuing decade produced a variety of clozapine-like drugs, based on the principle of some dopamine D2 receptor blockade, accompanied by serotonin (5-HT)2A or 5-HT1A, partial agonism, or both (Meltzer, 2001). The introduction of olanzapine, quetiapine, risperidone, ziprasidone, and zotepine has led to their replacing the D2 blockers as first-line therapy. Recently, a partial dopamine D2/D3 agonist mechanism accompanied by 5-HT1A partial agonism, and 5-HT2A antagonism (i.e. aripiprazole) has been found to have similar advantages to drugs like risperidone.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.