Sodium benzoate augments clozapine for schizophrenia
Sodium benzoate appears to augment the effects of clozapine, according to a recent study, which shows that the combination therapy results in significant improvements in symptomatology in clozapine-resistant schizophrenia patients.
The randomized, double-blind, placebo-controlled trial included 60 schizophrenia patients stabilized with clozapine who were randomized to receive one of three add-on treatments: 1 g/day of sodium benzoate (n=20), 2 g/day of sodium benzoate (n=20) or placebo (n=20). Add-on treatment was administered for an additional 60 days.
Both doses of sodium benzoate yielded significantly greater changes from baseline in the Scales for the Assessment of Negative Symptoms (SANS-20) scores relative to placebo at 6 weeks (p=0.029 for 1 g; p=0.031 for 2 g).
In comparison, only the 2-g sodium benzoate treatment resulted in significant 6-week improvements in the Positive and Negative Syndrome Scale (PANSS) scores compared with placebo (p=0.006).
Scores in the quality of life scale were also significantly better in the 2-g sodium benzoate vs placebo group at 6 weeks (p=0.009). No such effect was observed with 1 g of the add-on treatment.
In terms of secondary outcomes, neither 1 g or 2 g of add-on sodium benzoate resulted in significant 6-week improvements in depression, as per the Hamilton rating scale for depression (p=0.729 and p=0.114, respectively), and endpoint improvements in cognitive function (p=0.185 and p=0.930, respectively).
Minimal extrapyramidal syndrome was reported in all three groups both at baseline and at the conclusion of the study.