Dosing Schedules for Dextromethorphan and Piracetam in OCD: A Case Series on Diurnal Symptom Patterns and Split-Dosing Strategies

Off-label use of glutamatergic agents is increasingly common in psychiatry, yet standardized protocols for outpatient dosing are lacking. This report describes the pharmacological management and dosing adjustments required for three patients receiving dextromethorphan (DXM) and piracetam for obsessive–compulsive disorder.Three adult women with severe OCD were treated in a routine clinical setting. Treatment history varied from naïve to treatment-resistant. All patients commenced treatment with a nighttime regimen of oral DXM and piracetam to minimize potential side effects while maintaining existing psychotropic regimens.One patient achieved full remission on a once-nightly regimen. The last two patients showed a "wearing-off" effect, that their symptoms got better quickly after they woke up but then came back in the late afternoon, which neccesitated the schedule to be changed from once a day to twice a day (b.i.d.). This change fixed the afternoon symptom breakthrough without needing to raise the dose.Experience with these cases suggests that while bedtime administration is a safe starting point for routine care, the half-life of the agents may necessitate split dosing for some individuals. The observation that simple schedule adjustments can resolve diurnal symptom fluctuation provides a practical insight for psychiatrists managing OCD with glutamatergic augmentation.