Effects of modafinil on weight, glucose and lipid metabolism in clozapine-treated patients with schizophrenia.

RATIONALE: Sedation is a common side effect of clozapine treatment and may exacerbate metabolic consequences of poor diet and exercise habits that are common in patients with schizophrenia. Modafinil has been proposed as a treatment for clozapine-induced sedation and metabolic abnormalities.

OBJECTIVE

To estimate the effect sizes and person-to-person variation in anthropometric measures, glucose and lipid metabolism, and diet on modafinil treatment for future randomized control trials.

METHODS

A double-blind, placebo-controlled, flexible-dosed 8-week pilot trial was conducted, adding modafinil up to 300 mg/day to stabilized schizophrenia outpatients receiving clozapine. Blood pressure, weight, BMI, laboratory assays, and dietary intake were tracked to monitor changes in metabolic markers.

RESULTS

Thirty-five participants were randomly assigned to treatment with study drug or placebo and were included in the analysis. Modafinil did not improve blood pressure, weight, BMI, glucose or lipid metabolism compared to placebo. Modafinil was well tolerated and did not worsen psychosis.

CONCLUSIONS

Results of this pilot trial do not support routine use of modafinil to counteract increased weight and metabolic diseases in patients taking clozapine. However, the effects of modafinil on weight and insulin regulation warrant further investigation with effect sizes of 0.4 to 0.6.