Monthly Injectable Olanzapine Approved for Schizophrenia
The FDA has approved a once-monthly subcutaneous injectable version of olanzapine, called Weltruza, for adults with schizophrenia, according to Teva Pharmaceuticals. This long-acting formulation does not require loading doses or monitoring for post-injection delirium/sedation syndrome, a complication that has limited use of other long-acting olanzapine products. The decision was supported by the phase III SOLARIS trial, in which every dose group improved more than placebo on PANSS total scores.
Olanzapine, an oral atypical antipsychotic used for over 30 years, can pose adherence challenges with daily dosing. A monthly subcutaneous version now offers less frequent administration. It comes in three strengths matching 10-mg, 15-mg, and 20-mg oral doses. Unlike another long-acting olanzapine, it needs no loading dose or three-hour PDSS monitoring.
In SOLARIS, every dose beat placebo on PANSS total score at week 8, with mean differences from roughly -9.7 to -11.3 points. Secondary outcomes also favored treatment, and no PDSS occurred. Labeling still lists PDSS and other risks, including neuroleptic malignant syndrome, metabolic changes, tardive dyskinesia, and injection-site reactions. Frequent side effects were weight gain, drowsiness, headache, and constipation.
Adults with schizophrenia who struggle with daily oral medication, and their caregivers, could benefit from a monthly injection that may support steadier treatment and reduce adherence-related disruptions. Clinicians may gain an option that avoids some monitoring burdens linked to another long-acting olanzapine. Yet injections still require visits, and access, cost, or patient preference may limit uptake. Because serious risks remain, this approval may expand choices rather than replace existing care.