Importance: The treatment of schizophrenia remains a challenge, and the currently available antipsychotic drugs are slow acting and produce a number of adverse effects.
Objective: To examine the effectiveness and safety of a single intravenous administration of sodium nitroprusside (0.5 μg/kg/min for 4 hours) on the positive, negative, anxiety, and depressive symptoms in patients with schizophrenia.
Design: Single-center, randomized, double-blind, placebo-controlled trial performed from March 9, 2007, to March 12, 2009.
Setting: University teaching hospital in São Paulo, Brazil.
Participants: Twenty inpatients aged 19 to 40 years with a diagnosis of schizophrenia who were in the first 5 years of the disease who are taking antipsychotics.
Intervention: Sodium nitroprusside administration.
Main Outcome Measures: The 18-item Brief Psychiatric Rating Scale and the negative subscale of the Positive and Negative Syndrome Scale.
Results: After the infusion of sodium nitroprusside, a rapid (within 4 hours) improvement of symptoms was observed. The placebo and experimental groups had significant differences in the 18-item Brief Psychiatric Rating Scale total score and subscale scores, which persisted for 4 weeks after infusion.
Conclusions: The results clearly show a therapeutic effect of sodium nitroprusside. If this drug is approved for routine clinical use in patients with schizophrenia, this discovery will be an important advance in the pharmacologic treatment of this devastating disorder.
Trial Registration: clinicaltrials.gov Identifier: NCT01548612