Can Ingrezza Cause Confusion in Schizophrenic Patients?
Ingrezza (valbenazine) does not directly cause confusion in patients with schizophrenia, and clinical trials specifically demonstrated that psychiatric status remained stable during treatment. 1, 2
Evidence from Clinical Trials in Schizophrenia Patients
In the pivotal KINECT 3 trial, approximately 65% of participants had schizophrenia or schizoaffective disorder, and 85.5% were receiving concomitant antipsychotics—psychiatric status remained stable throughout the study with no evidence of confusion as a side effect. 1
Long-term data from the 1-year extension study (48 weeks of treatment) showed that participants remained psychiatrically stable, with no apparent worsening of cognitive or psychiatric symptoms. 2
Valbenazine was generally well tolerated in this population, with the most common adverse events being somnolence and anticholinergic effects, but confusion was not identified as a treatment-emergent adverse event. 1, 3
Important Distinction: Confusion vs. Underlying Illness
Patients with schizophrenia may experience "persistent confusion, disorganization, and dysphoria" during the recuperative phase (4-12 weeks after acute psychosis) as part of their underlying illness, not as a medication side effect. 4
If confusion appears in a schizophrenia patient taking Ingrezza, first consider whether it represents inadequately treated psychotic symptoms, medication non-adherence, or other causes rather than attributing it to valbenazine. 4
Critical Monitoring Considerations
Valbenazine does not induce or worsen akathisia or parkinsonism, which can sometimes be mistaken for confusion or agitation in patients with schizophrenia. 2
No apparent risk for suicidal ideation or behavior was found during long-term treatment, indicating overall psychiatric stability. 2
The medication has a favorable short-term side effect profile compared to older VMAT2 inhibitors like tetrabenazine, with once-daily dosing and better tolerability. 3
Clinical Bottom Line
Ingrezza is safe to use in schizophrenia patients taking antipsychotics without concern for causing confusion—the drug was specifically studied in this population with favorable psychiatric stability outcomes. 1, 2 If confusion develops, investigate other causes including disease progression, antipsychotic side effects (particularly anticholinergic effects from high-potency agents), or inadequate treatment of psychotic symptoms rather than attributing it to valbenazine. 4