Cluster Headache: Acute Treatment
Cluster headache attacks are among the most severe pain syndromes in medicine — often called "suicide headache." Attacks peak rapidly (within 5-15 minutes), last 15-180 minutes, and occur 1-8 times daily during a cluster bout. This rapid onset and short duration demand fast-acting treatments. Oral medications are too slow. The two evidence-based acute treatments are high-flow oxygen and injectable/nasal triptans.
Bottom Line
- High-flow oxygen (100% O2 at 12-15 L/min via non-rebreather mask for 15-20 minutes): Level A. First-line. Effective in ~78% of attacks. No side effects. No limit on daily use.
- Sumatriptan 6 mg SC: Level A. Pain-free by 15 minutes in ~75%. First-line when oxygen is unavailable or insufficient. Max 2 injections/24 hours.
- Sumatriptan/zolmitriptan nasal spray: Level A/B. Slightly slower than injection but effective. Good for patients who refuse or cannot use injection.
- Oral triptans are too slow for cluster attacks — do not prescribe oral triptans for acute cluster treatment
- Opioids and butalbital are ineffective and should not be used
Cluster Headache: Diagnostic Overview
ICHD-3 Criteria
- A. At least 5 attacks fulfilling B-D
- B. Severe or very severe unilateral orbital, supraorbital, and/or temporal pain lasting 15-180 minutes (untreated)
- C. Either or both:
- At least one ipsilateral autonomic sign: conjunctival injection, lacrimation, nasal congestion, rhinorrhea, forehead/facial sweating, miosis, ptosis, eyelid edema
- A sense of restlessness or agitation
- D. Frequency: 1 every other day to 8/day during a bout
| Feature | Episodic Cluster (~85%) | Chronic Cluster (~15%) |
|---|---|---|
| Pattern | Bouts lasting 2 weeks to 3 months, separated by remission periods ≥3 months | Attacks for ≥1 year without remission, or remissions <3 months |
| Circadian/circannual | Attacks cluster at same time of day (often 1-2 AM); bouts often recur at same season | Same attack pattern but continuous |
| Demographics | 3:1 male predominance; mean onset age 20-40 years; smokers overrepresented | |
High-Flow Oxygen
Oxygen Therapy: Practical Guide
- Prescription: "Oxygen 100% via non-rebreather mask at 12-15 L/min for cluster headache, PRN up to 15-20 minutes per attack." Requires a written prescription for home O2 supply.
- Setup: Large (M or H size) oxygen cylinder at home + portable E-cylinder for travel. Non-rebreather mask (not nasal cannula — insufficient flow rate).
- Technique: Patient sits upright, leaning slightly forward. Deep, steady breaths through the mask. Continue for 15-20 minutes or until attack resolves.
- Efficacy: ~78% of attacks respond within 15 minutes (Cohen 2009, RCT). Some patients respond only at 15 L/min, not 12 L/min — trial higher flow if needed.
- Advantages: No side effects, no daily dose limit, no drug interactions, can be used multiple times per day
- Limitations: Bulky equipment, not portable for all settings, cost varies by insurance, requires prescription and supplier coordination
- Demand valve system: Some patients do better with demand-valve oxygen (higher flow on inhalation). More efficient oxygen use.
Cohen et al. (Lancet 2009): Randomized, double-blind, placebo-controlled crossover trial of 100% O2 at 12 L/min vs air. Pain-free or adequate relief at 15 minutes: 78% vs 20% (p<0.001).
Triptans
| Agent | Route / Dose | Evidence | Notes |
|---|---|---|---|
| Sumatriptan SC | 6 mg subcutaneous injection | Level A. Pain-free at 15 min: ~75% (Ekbom 1991). Multiple positive RCTs. | First-line triptan. Autoinjector pen for self-administration. Max 2 injections/24 hours (separated by ≥1 hour). Most rapid non-oxygen option. |
| Sumatriptan nasal spray | 20 mg | Level B. Effective within 30 minutes. Positive RCTs. | Alternative when injection refused or unavailable. Slower onset than SC. Bitter taste; some absorption is GI (swallowed portion), not purely nasal. |
| Zolmitriptan nasal spray | 5-10 mg | Level B. Cittadini (2006): 10 mg effective in episodic cluster. Positive RCT. | Good nasal alternative. 10 mg dose may be more effective than 5 mg for cluster (higher than migraine dose). |
| Oral triptans | Any | Not recommended. Onset too slow (30-60 min) for a 15-180 minute attack. | By the time an oral triptan works, the attack is often already resolving spontaneously. |
Triptan Safety in Cluster Patients
- Cardiovascular screening: Cluster patients are often male smokers with cardiovascular risk factors. Standard triptan contraindications apply (uncontrolled hypertension, CAD, prior stroke, PVD).
- Frequency of use: During active bouts, patients may need sumatriptan SC daily or multiple times daily. Limit to 2 SC injections/24 hours. If attacks are more frequent than triptan dosing allows, prioritize oxygen for some attacks and reserve triptans for breakthrough.
- MOH risk: Triptan overuse headache is theoretically possible but less of a concern in cluster headache than in migraine, as cluster bouts are time-limited.
Other Acute Options
| Agent | Details | Evidence / Role |
|---|---|---|
| Lidocaine intranasal | 4% lidocaine, 1 mL instilled into ipsilateral nostril with head extended and rotated 30° toward affected side | Level C. Targets sphenopalatine ganglion. Modest effect; not sufficient as monotherapy. Can be adjunct. |
| Octreotide SC | 100 μg SC | Level B. Matharu (2004): positive RCT. Somatostatin analogue. Alternative for patients with triptan contraindications. |
| gammaCore (nVNS) | Non-invasive vagus nerve stimulator, 2-minute stimulation at attack onset | Level B. ACT1 trial: positive for acute episodic cluster. FDA-cleared. Adjunct to oxygen/triptan or alternative for triptan-contraindicated patients. |
| Dihydroergotamine (DHE) | 1 mg IM or SC | Limited evidence for acute cluster. Slower onset than sumatriptan SC. Cannot combine with triptans (vasospasm risk). Reserved for infrequent use. |
Practical Acute Algorithm
- At attack onset: High-flow O2 100% at 12-15 L/min via non-rebreather × 15-20 min
- If O2 unavailable or insufficient: Sumatriptan 6 mg SC (or 3 mg if preferred for frequent use)
- If SC injection refused: Zolmitriptan 5-10 mg nasal spray or sumatriptan 20 mg nasal spray
- If triptan contraindicated: gammaCore nVNS or octreotide 100 μg SC
- Adjunct for all attacks: Intranasal lidocaine 4% ipsilateral
Most patients should have both oxygen at home and sumatriptan SC available, using oxygen as the default and triptans for breakthrough or when oxygen is unavailable.
What Does NOT Work
- Oral triptans: Too slow
- Acetaminophen, NSAIDs: Too slow and insufficient for the severity
- Opioids: Ineffective for cluster headache and risk dependence
- Butalbital combinations: Ineffective
- Oxygen at low flow (<10 L/min) or via nasal cannula: Insufficient delivery; use non-rebreather at ≥12 L/min
References
- Cohen AS, et al. High-flow oxygen for treatment of cluster headache: a randomised trial. JAMA. 2009;302(22):2451-2457.
- Ekbom K, et al. Subcutaneous sumatriptan in the acute treatment of cluster headache. Acta Neurol Scand. 1991;84(6):478-481.
- Cittadini E, et al. Effectiveness of intranasal zolmitriptan in acute cluster headache. Neurology. 2006;67(1):150-152.
- May A, et al. Cluster headache. Nat Rev Dis Primers. 2018;4:18006.
- Robbins MS, et al. Treatment of cluster headache: the American Headache Society evidence-based guidelines. Headache. 2016;56(7):1093-1106.