Summary In 2025, a nationwide shortage of long-acting injectable olanzapine (Zypadhera) forced treatment changes in patients at the Mental Health Day Hospital of Mataró (Spain). We retrospectively identified 23 consecutive patients receiving Zypadhera and recorded subsequent therapeutic alternatives, relapse, service disengagement and re-initiation of Zypadhera. Relapse or disengagement occurred in 39% of patients, with significantly fewer events observed among patients switched to oral olanzapine compared with long-acting injectable aripiprazole (log-rank P = 0.008). Female sex, younger age and tobacco use were associated with increased risk. This study highlights the need for contingency planning and careful selection of alternatives.
