What DHE migraine protocol works best for acute treatment both in terms of dosage and timeframe?

Dihydroergotamine (DHE) is a non-specific ergot that acts on the serotonergic, dopaminergic, and adrenergic pathways. It is used as an acute migraine treatment that can be given parenterally or nasally. Oral does exist, but is not available in the USA. It may be used acutely as a rescue treatment during an attack or may be provided as infusion often over days.

RESCUE TREATMENT:

- Injection (IM/SC) and Nasal can be used acutely similar to triptans (but should not be used within 24h of a triptan).

- I will try DHE as an acute treatment in patients who are triptan non-responders as well as in those needing a rapid onset (compared to oral meds), or those who catch their attacks late (e.g. wake-up attacks in the morning). In patients prone to vomi...