The intramuscular olanzapine era
The prior long-acting olanzapine was given intramuscularly and linked to post-injection delirium/sedation syndrome, where too much drug enters the bloodstream too quickly. Patients needed extended observation after each dose.
Clinics built observation time into every injection visit, making injectable olanzapine logistically heavy.
The monitoring burden shaped how readily clinicians prescribed injectable olanzapine, steering many toward alternative antipsychotics.
WELTRUZA removes the monitoring requirement. Its label still describes the PDSS risk from the intramuscular product, and says it's unknown whether the syndrome can occur with the subcutaneous formulation.
