Successive clinical application of vitamin D and bumetanide in children with autism spectrum disorder: A case report.

RATIONALE: Autism spectrum disorder (ASD) is a common neurodevelopmental disorder caused by complex interactions between genetic and environmental factors. Recent studies suggest that Vitamin D3 or bumetanide therapy may improve the core symptoms of ASD in some individuals. However, there are no guidelines that provide clinicians with evidence-based treatment regimens for the use of these therapies in ASD. PATIENT CONCERNS: A 30-month-old female was referred to our department because she did not respond when her name was called. DIAGNOSIS: The patient was diagnosed with ASD by a team of autism experts according to American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria. INTERVENTIONS: The patient was administered Vitamin D3 150,000 IU intramuscularly once a month and Vitamin D3 800 IU orally each day. After 6 months, Vitamin D3 supplementation was discontinued because of lack of effectiveness. Subsequently, oral bumetanide 0.5 mg twice daily was initiated. OUTCOMES: The patient's symptoms remained unchanged after 6 months of Vitamin D3 supplementation, and her serum 25 (OH) D levels had reached 52.4 ng/mL. At the parent's request, Vitamin D3 supplementation was discontinued because of lack of effectiveness. Thereafter, bumetanide was initiated. After 1 month of bumetanide, the patient's Childhood Autism Rating Scale score was 26, which is below the cutoff score for ASD. This case report suggests that Vitamin D3 and bumetanide target different mechanisms in the pathogenesis of ASD. LESSONS: Based on these observations, we discuss three possible scenarios for Vitamin D3 supplementation and propose that bumetanide should be initiated if Vitamin D3 supplementation is ineffective (identifier ChiCTR-CCC-13004498).