Sarcosine or D-Serine Add-on Treatment for Chronic Schizophrenia
Both GlyT-1 inhibitors and NMDA-glycine site agonists have been demonstrated to be beneficial for chronic schizophrenia patients.
The purpose of this study is to compare efficacy and safety of add-on treatment of sarcosine, a GlyT-1 inhibitor, and D-serine, an NMDA-glycine site agonist, in chronically stable schizophrenia patients who have been stabilized with antipsychotics.
Drug: Sarcosine and D-serine
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Primary Purpose: Treatment
|Official Title:||NMDA Enhancers in the Treatment of Schizophrenia: Sarcosine vs. D-Serine|
- Total scores of Positive and Negative Syndrome Scale (PANSS) and Quality of Life (QOL) [ Time Frame: 6 weeks ]
- Subscales of PANSS [ Time Frame: 6 weeks ]
|Study Start Date:||January 2005|
|Study Completion Date:||December 2006|
The etiology of schizophrenia remains unclear. Schizophrenia patients reveal positive symptoms, negative symptoms, and cognitive impairments. In addition to dopamine system hyperactivity, hypofunction of N-methyl-D-aspartate (NMDA) receptor plays a role in the pathophysiology of schizophrenia. Consequently, enhancing NMDA receptor neurotransmission has been regarded as a novel treatment approach. To date, there have been several reported trials on NMDA enhancers. Both sarcosine (N-methylglycine, a glycine transporter I inhibitor) and D-serine (a potent NMDA-glycine site agonist) showed therapeutic effects in chronically stable patients. Interestingly, sarcosine appeared more efficacious than D-serine in acutely exacerbated ones when added-on to antipsychotics. Both sarcosine and D-serine yielded excellent safety profiles.
It remains unclear whether sarcosine can be also more efficacious than D-serine in the treatment for chronically stable schizophrenia. The aim of this project is to examine the efficacy and safety of add-on treatment of sarcosine vs. D-serine in chronically stable schizophrenia patients who have been stabilized with antipsychotics.
In the study, 60-75 schizophrenic patients are recruited into the 6-week trial and randomly assigned into the three groups (2 gm/d sarcosine, 2 gm/d D-serine, or placebo) with a double-blind manner. Clinical manifestation (Positive and Negative Syndrome Scale [PANSS], side effects and quality of life (QOL) are evaluated every two weeks during the trial.. The efficacies of three groups are compared.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00491569
|China Medical University Hospital|
|Taichung, Taiwan, 404|
|Principal Investigator:||Hsien-Yuan Lane, MD,PhD||Department of Psychiatry, China Medical University Hospital, Taiwan|