This trial is a prospective, randomized, feasibility trial with the primary aim of comparing how well oral rapidly dissolving olanzapine controls primary headache pain when compared to the current treatment strategies used in emergency departments which often require intravenous or intramuscular medications.

Primary Question:

Does oral rapidly dissolving olanzapine provide efficacious analgesia in patients with acute headache of non-organic origin (primary headache) who come to the ED for abortive therapy when compared to current standard of care?

Secondary Aim:

Additionally, the study will aim to see if oral rapidly dissolving olanzapine decreases 1) duration of ED length of stay and 2) need for IV access when compared to the current standard of care.

This is a prospective, randomized, convenience sample, feasibility trial to test for non-inferiority of oral rapidly dissolving olanzapine versus current emergency department standard of care in providing symptomatic relief to patients presenting with primary headache.

Inclusion Criteria:

1. Adult patient between 18-65 years of age presenting to the emergency department with acute primary headache
2. Patient approved for inclusion by primary attending physician in the emergency department

Exclusion Criteria:

1. Age < 18 or > 65
2. Pregnancy
3. Known allergy to olanzapine
4. Known QT prolongation or underlying condition that places patient at risk for QT prolongation
5. Inability to give written consent (intoxication, altered mental status)
6. Headache of organic origin (trauma, infection, previous recent head or neck surgery)
7. Patient already prescribed daily olanzapine on an outpatient basis
8. Patient has been administered olanzapine within the past 24 hours
9. Language barrier

The baseline population included is 119 as 5 subjects withdrew after providing informed consent.

Adverse event data were collected until completion of the 48 hour follow-up phone call (24-72 hours following enrollment).

Open label, not blinded, randomized 2-arm trial