As a glucocorticoid , the lipophilic structure of prednisolone allows for easy passage through the cell membrane where it then binds to its respective glucocorticoid receptor (GCR) located in the cytoplasm. Upon binding, formation of the GC/GCR complex causes dissociation of chaperone proteins from the glucocorticoid receptor enabling the GC/GCR complex to translocate inside the nucleus. This process occurs within 20 minutes of binding. Once inside the nucleus, the homodimer GC/GCR complex binds to specific DNA binding-sites known as glucocorticoid response elements (GREs) resulting in gene expression or inhibition. Complex binding to positive GREs leads to synthesis of anti-inflammatory proteins while binding to negative GREs block the transcription of inflammatory genes. 
In a double-blind randomized controlled trial that evaluated the emergency department treatment of migraine in 66 patients, the combination of IV prochlorperazine (10 mg) and IV diphenhydramine ( mg) was significantly more effective than subcutaneous sumatriptan (6 mg) for the reduction of pain intensity at 80 minutes or time of discharge [ 79 ]. Diphenhydramine was used with prochlorperazine to prevent akathisia and dystonic reactions. However, the possibility of migraine benefit from diphenhydramine cannot be completely discounted. A high drop-out rate upon attempted telephone contact at 72 hours precluded meaningful assessment of headache recurrence, although none of the enrolled patients returned to the emergency department with complaint of headache.