Most evidence supporting antipsychotics as a treatment for migraine headaches and cluster headaches is based on small studies and chart reviews. Some research suggests antipsychotics may effectively treat nausea but side effects such as akathisia may limit their use.
Migraine headaches
Antipsychotic treatment of migraines is supported by the theory that dopaminergic hyperactivity leads to migraine headaches (Table 1). Antipsychotics have been used off-label in migraine patients who do not tolerate triptans or have status migrainosus—intense, debilitating migraine lasting >72 hours.1 Primarily a result of D2 receptor blockade, the serotonergic effects of some second-generation antipsychotics (SGAs) may prevent migraine recurrence. The first-generation antipsychotics (FGAs) prochlorperazine, droperidol, haloperidol, and chlorpromazine have been used for migraine headaches (Table 2).1-27
Prochlorperazine may be an effective treatment of acute headaches9 and refractory chronic daily headache.10 Studies show that buccal prochlorperazine is more effective than oral ergotamine tartrate11 and IV prochlorperazine is more effective than IV ketorolac12 or valproate28 for treating acute headache.
Evidence suggests that chlorpromazine administered IM2 or IV3 is better than placebo for managing migraine pain. In a study comparing IV chlorpromazine, lidocaine, and dihydroergotamine, patients treated with chlorpromazine showed more persistent headache relief 12 to 24 hours post-dose.4 In another study, IV chlorpromazine, 25 mg, was as effective as IM ketorolac, 60 mg.5
Droperidol has been shown to be effective for managing headache, specifically status migrainosus.6 Patients with “benign headache”—headache not caused by an underlying medical disorder—who received droperidol reported greater reduction in visual analog pain scores within 1 hour of dosing compared with those taking prochlorperazine.7 In a randomized trial comparing IM droperidol and IM meperidine, patients with an acute migraine who received droperidol had improved scores on the visual pain analog scale and required less “rescue medication” for breakthrough pain.8 The FDA has issued a “black-box” warning of QTc prolongation with droperidol.
In a double blind, placebo-controlled trial, IV haloperidol, 5 mg, effectively treated migraine headache in 80% of patients compared with 15% of those who received placebo. However, 16% of patients considered the side effects—mainly sedation and akathisia—intolerable and 7% had symptom relapse.13 In an open-label trial of 6 patients with migraine headache, all patients achieved complete or substantial headache relief 25 to 65 minutes after receiving IV haloperidol, 5 mg.14
SGAs often antagonize 5-HT1D receptors and theoretically can render triptan therapy—which stimulates pre-synaptic 5-HT1D receptors—ineffective. This has not been seen clinically and instead, dose-related, non-specific headaches are a common adverse event with SGAs.29,30 A retrospective chart review found olanzapine provided relief for refractory headaches in patients who had failed ≥4 preventive medications. Olanzapine significantly decreased headache days, from 27.5±4.9 before treatment to 21.1±10.7 after treatment. Olanzapine also improved headache severity (measured on a 0 to 10 scale) from 8.7±1.6 before treatment to 2.2±2.1 after treatment.16 Researchers found that 2.5 or 5 mg of olanzapine relieved acute migraines for most patients, with repeat dosing as needed up to 20 mg/d. For prophylactic treatment, 5 or 10 mg of olanzapine was used. Olanzapine’s antinociceptive effect may be related to its action on α-2 adrenoreceptors and to a lesser extent on involvement of opioid and serotonergic receptors.17
In a case series, 3 migraine patients who met criteria for chronic daily headache and migraines but did not have a psychiatric disorder reported significant and sustained headache improvement when treated with risperidone.19 In a case series of 3 migraine patients with co-occurring psychiatric disorders, aripiprazole decreased migraine frequency and severity.15 Although limited data support quetiapine’s efficacy in treating acute migraines, in an open-label, pilot study, patients taking quetiapine, 25 to 75 mg/d, demonstrated a decrease in mean frequency of migraine days from 10.2 to 6.2 and decreased use of rescue medications from 2.3 to 1.2 days per week.18
Table 1
Possible rationale for antipsychotic use for headaches and nausea
| Condition | Possible rationale |
|---|---|
| Migraine | Patients are hypersensitive to dopamine agonists or dopamine transporter dysfunction. Some evidence that the dopamine D2 (DRD2) gene is involved |
| Cluster headache | Pain alleviation possibly related to dopamine receptor antagonism |
| Nausea | D2 and H1 receptor blockage |
Table 2
Antipsychotics for headache and nausea: Strength of the evidence
| Condition | Strength of evidencea |
|---|---|
| Migraine | Intermediate: Chlorpromazine,2-5 droperidol,6-8 prochlorperazine1,10-12 |
| Weak: Haloperidol13,14 | |
| Very weak: Aripiprazole,15 olanzapine,16,17 quetiapine,18 ziprasidone19 | |
| Cluster headache | Weak: Chlorpromazine20 |
| Very weak: Clozapine,21 olanzapine22 | |
| Nausea/vomiting | Intermediate: Droperidol,23 metoclopramide,24 prochlorperazine,25 promethazine25 |
| Weak: Olanzapine26,27 | |
| aStrong: Multiple, well-designed RCTs directly relevant to the recommendation, yielding consistent findings Intermediate: Some evidence from RCTs that support the recommendation, but the scientific support was not optimal Weak: Consensus recommendation in the absence of relevant randomized controlled trials and better evidence than case report or series Very weak: Case reports or case series or preliminary studies RCTs: randomized controlled trials | |