Tetrabenazine-Induced Rapid-Onset Suicidality in an Adolescent With Schizophrenia and Obsessive-Compulsive Disorder

Tetrabenazine, a vesicular monoamine transporter inhibitor, is approved for treating chorea in Huntington disease and used off-label for hyperkinetic movement disorders.¹ Although its labeling includes a boxed warning for depression and suicidality, most safety data derive from adult Huntington cohorts on moderate-to-high doses.^2,3 Reports in adolescents with primary psychiatric disorders are scarce, and to our knowledge, no published cases describe rapid-onset suicidality at low doses in this population.

Case Report

We report the case of a 19-year-old male with schizophrenia and obsessive-compulsive disorder (OCD) who developed acute suicidality after low-dose tetrabenazine. He presented with contamination obsessions, ritualistic behaviors, and persistent second-person auditory hallucinations. A family history of suicide was noted. Initially, fluoxetine was started at 20 mg/d and titrated over several weeks to 80 mg/d, leading to substantial improvement in OCD symptoms. However, psychotic symptoms persisted. Risperidone was then initiated at 2 mg/d and increased to 6 mg/d, achieving remission.

One week postdischarge, he developed a simple motor tic involving repetitive facial movements. Suspecting an antipsychotic-induced tic or idiopathic tic disorder, tetrabenazine was initiated at 12.5 mg/d. Given concurrent fluoxetine, a potent cytochrome P450 (CYP) 2D6 inhibitor known to elevate tetrabenazine exposure, the treatment team decided to limit the dose to 25 mg/d and avoid further escalation.

Within 3 days of increasing tetrabenazine to 25 mg/d, the patient developed pervasive suicidal ideation with a specific plan and a narrowly averted attempt. On readmission, he was assessed as category 5 on the Columbia Suicide Severity Rating Scale.⁴ Laboratory evaluations were unremarkable. Tetrabenazine was discontinued immediately with no additional pharmacologic interventions. Suicidal ideation resolved within 5 days of cessation. A Naranjo Adverse Drug Reaction Probability Scale⁵ score of 7 indicated probable causality.

Discussion

This case highlights 3 key considerations. First, even low-dose tetrabenazine can rapidly precipitate life-threatening suicidality in adolescents with primary psychiatric disorders. Second, the abrupt onset within 72 hours emphasizes the need for close monitoring. Third, the presence of fluoxetine likely potentiated tetrabenazine’s effects via CYP2D6 inhibition, further increasing risk.

Clinicians should exercise caution when prescribing tetrabenazine in adolescents, especially those with preexisting psychiatric conditions and concomitant CYP2D6 inhibitors. Careful dose selection, close monitoring for emergent suicidality, and thorough patient and family education are essential. Our observation underscores the need for further research to clarify tetrabenazine’s safety profile in younger psychiatric populations.

Article Information

Published Online: December 9, 2025. https://doi.org/10.4088/PCC.25cr04045
© 2025 Physicians Postgraduate Press, Inc.
Prim Care Companion CNS Disord 2025;27(6):25cr04045
Submitted: July 16, 2025; accepted August 26, 2025.
To Cite: Manivel S, Priyadharshini SBS. Tetrabenazine-induced rapid-onset suicidality in an adolescent with schizophrenia and obsessive-compulsive disorder. Prim Care Companion CNS Disord 2025;27(6):25cr04045.
Author Affiliations: Department of Psychiatry, KMCH Institute of Health Science and Research, Coimbatore, Tamilnadu, India (both authors).
Corresponding Author: Sathyaseelan Manivel, MD,KMCH Institute of Health Science and Research, Coimbatore, Tamilnadu, India ([email protected]).
Relevant Financial Relationships: None.
Funding/Support: None.
Patient Consent: Written informed consent was obtained from the patient’s legal guardian to publish the case report, and information has been de-identified to protect patient anonymity.
ORCID: Sathyaseelan Manivel: https://orcid.org/0009-0005-8205-2879