What are the recommended injectable treatments for an acute migraine attack, including dosing, contraindications, and alternative options if triptans are unsuitable?

Injectable Treatments for Acute Migraine

For acute migraine requiring injectable therapy, use subcutaneous sumatriptan 6 mg or intravenous prochlorperazine 10 mg as first-line treatment, with greater occipital nerve blocks as an equally effective alternative. 1

First-Line Injectable Options

The 2025 American Headache Society emergency department guideline establishes three Level A ("must offer") treatments for acute migraine requiring parenteral therapy 1:

• Subcutaneous sumatriptan (typically 6 mg)
• Intravenous prochlorperazine (10 mg)
• Greater occipital nerve blocks (GONB)

These three options have multiple Class I studies demonstrating efficacy and should be offered to all eligible patients without contraindications 1.

When to Use Non-Oral Triptans

Consider non-oral triptan formulations when patients have severe nausea or vomiting, as gastrointestinal dysmotility during migraine attacks impairs oral medication absorption 2, 3. The 2025 American College of Physicians guideline specifically recommends non-oral triptans with antiemetics for patients experiencing significant gastrointestinal symptoms 2.

Second-Line Injectable Options (Level B - "Should Offer")

If first-line treatments fail or are contraindicated 1:

• Intravenous metoclopramide (10 mg)
• Intravenous ketorolac (30 mg)
• Intravenous dexketoprofen
• Supraorbital nerve blocks (SONB)

These have one Class I study or multiple Class II studies supporting efficacy.

Third-Line Options (Level C - "May Offer")

• Intravenous chlorpromazine (12.5-25 mg)
• Intravenous dexamethasone (10-24 mg) - particularly useful for preventing headache recurrence 1
• Intravenous valproate (500-1000 mg)

Critical Contraindications

Triptan Contraindications

Triptans cause vasoconstriction and are absolutely contraindicated in patients with:

• Coronary artery disease or history of myocardial infarction
• Cerebrovascular disease or stroke
• Peripheral vascular disease
• Uncontrolled hypertension
• Hemiplegic or basilar migraine

Important note: The newer gepants (CGRP antagonists) and ditans do NOT have vascular contraindications, making them valuable alternatives for patients with cardiovascular risk factors 4, 5. However, these are primarily oral formulations and not typically used as injectable acute treatments in emergency settings.

Medications to Avoid

Do NOT use opioids (including hydromorphone and morphine) or butalbital-containing medications for acute migraine treatment 2, 1. The 2025 AHS guideline gives hydromorphone a Level A "must not offer" recommendation based on Class I evidence showing lack of efficacy 1. The 2016 guideline similarly recommended avoiding morphine and hydromorphone as first-line therapy 6.

Intravenous paracetamol (acetaminophen) is also likely ineffective and may not be offered (Level C) 1.

Dosing Specifics

Sumatriptan Subcutaneous

• Standard dose: 6 mg SC
• May repeat once after 1 hour if needed
• Maximum: 12 mg per 24 hours

Prochlorperazine IV

• Standard dose: 10 mg IV
• Administer slowly to reduce akathisia risk
• Consider prophylactic diphenhydramine 25-50 mg to prevent dystonic reactions

Greater Occipital Nerve Block

• Inject 2-3 mL of local anesthetic (lidocaine 1-2% or bupivacaine 0.5%) with or without corticosteroid
• Bilateral injection at the occipital notch, approximately one-third the distance from the external occipital protuberance to the mastoid process

Special Populations

Pregnancy and Lactation

The 2025 ACP guideline emphasizes discussing adverse effects of pharmacologic treatments with people of childbearing potential, pregnant, or breastfeeding patients 2. Most injectable migraine medications have limited safety data in pregnancy. Metoclopramide has the most reassuring pregnancy data among antiemetics.

Cardiovascular Disease

For patients with cardiovascular contraindications to triptans, consider:

• Dopamine antagonists (prochlorperazine, metoclopramide, chlorpromazine)
• NSAIDs (ketorolac, dexketoprofen)
• Nerve blocks
• Oral gepants or ditans (though not injectable formulations)

Common Pitfalls

1. Medication overuse headache: Triptans used ≥10 days per month can cause rebound headaches 2. Injectable formulations carry the same risk.

2. Inadequate dosing: Ensure full therapeutic doses are used before declaring treatment failure. Subcutaneous sumatriptan 6 mg is more effective than lower doses.

3. Delayed treatment: Counsel patients to treat as early as possible after migraine onset for optimal efficacy 2.

4. Akathisia with dopamine antagonists: This distressing adverse effect occurs in up to 20% of patients receiving prochlorperazine or metoclopramide. Consider prophylactic diphenhydramine.

5. Assuming all triptans are equivalent: While the evidence supports the triptan class, subcutaneous sumatriptan has the fastest onset and highest efficacy among triptan formulations 3.

Algorithm for Injectable Treatment Selection

Step 1: Assess for triptan contraindications (cardiovascular disease, uncontrolled hypertension)

• If NO contraindications → Subcutaneous sumatriptan 6 mg
• If contraindications present → Prochlorperazine 10 mg IV or GONB

Step 2: If first-line treatment fails after 1-2 hours

• Add or switch to IV ketorolac 30 mg or IV metoclopramide 10 mg

Step 3: If still inadequate response

• Consider IV chlorpromazine 12.5-25 mg or IV valproate 500-1000 mg
• Add IV dexamethasone 10-24 mg to prevent recurrence

Step 4: For refractory cases

• Consider dihydroergotamine IV (if no triptan use in past 24 hours and no vascular contraindications)
• Transition to oral gepants or ditans for outpatient management