BACKGROUND: Small molecules that enhance the N-methyl-D-aspartate (NMDA) neurotransmission have been shown to be beneficial as adjuvant therapy for schizophrenia. Among these compounds, sarcosine (a glycine transporter-I inhibitor), when added to an existing regimen of antipsychotic drugs, has shown its efficacy for both chronically stable and acutely ill patients. However, the efficacy of these agents as a primary antipsychotic agent has not yet been demonstrated. METHODS:Twenty acutely symptomatic drug-free patients with schizophrenia were randomly assigned under double-blind conditions to receive a 6-week trial of 2 g or 1 g of sarcosine daily. RESULTS: Overall, patients in the 2-g group were more likely to respond as defined by a 20% or more reduction of the Positive and Negative Syndrome Scale total score, particularly among antipsychotic-naïve patients. However, there was no significant between-group difference in the sarcosine dose x time interaction analysis. Both doses were well tolerated with minimal side effects. CONCLUSIONS: Although patients receiving the 2-g daily dose were more likely to respond, it requires further clarification whether the effect is limited to the antipsychotic-naive population. Future placebo- or active-controlled, larger-sized studies are needed to fully assess sarcosine's effects.
RCT Entities:
BACKGROUND: Small molecules that enhance the N-methyl-D-aspartate (NMDA) neurotransmission have been shown to be beneficial as adjuvant therapy for schizophrenia. Among these compounds, sarcosine (a glycine transporter-I inhibitor), when added to an existing regimen of antipsychotic drugs, has shown its efficacy for both chronically stable and acutely ill patients. However, the efficacy of these agents as a primary antipsychotic agent has not yet been demonstrated. METHODS: Twenty acutely symptomatic drug-free patients with schizophrenia were randomly assigned under double-blind conditions to receive a 6-week trial of 2 g or 1 g of sarcosine daily. RESULTS: Overall, patients in the 2-g group were more likely to respond as defined by a 20% or more reduction of the Positive and Negative Syndrome Scale total score, particularly among antipsychotic-naïve patients. However, there was no significant between-group difference in the sarcosine dose x time interaction analysis. Both doses were well tolerated with minimal side effects. CONCLUSIONS: Although patients receiving the 2-g daily dose were more likely to respond, it requires further clarification whether the effect is limited to the antipsychotic-naive population. Future placebo- or active-controlled, larger-sized studies are needed to fully assess sarcosine's effects.
Authors: Stephen F Traynelis; Lonnie P Wollmuth; Chris J McBain; Frank S Menniti; Katie M Vance; Kevin K Ogden; Kasper B Hansen; Hongjie Yuan; Scott J Myers; Ray Dingledine Journal: Pharmacol Rev Date: 2010-09 Impact factor: 25.468