1.2 Triptans

1.2.1 Subcutaneous sumatriptan — the strongest acute drug

peer-reviewed The Sumatriptan Cluster Headache Study Group. “Treatment of acute cluster headache with sumatriptan.” N Engl J Med. 1991;325(5):322–6 (PMID 1647496, DOI 10.1056/NEJM199108013250505). Double-blind placebo-controlled crossover, 49 enrolled, 39 evaluable, 6 mg subcutaneous.

Outcome	Sumatriptan 6 mg SC	Placebo	p
Headache severity decreased at 15 min	74% of attacks	26%	<0.001
Pain-free at 10 min	36%	3%	<0.001
Pain-free at 15 min	46%	10%	<0.001
Required rescue oxygen	13%	49%	—

No serious adverse events. The Australian Prescriber review reports the equivalent figures as mild or no pain at 15 min: 75% vs 32% placebo; pain-free at 15 min: 48% vs 17% (Aust Prescr 2022).

peer-reviewed Law S, Derry S, Moore RA. “Triptans for acute cluster headache.” Cochrane Database Syst Rev. 2010;(4):CD008042 (PMC4170909, DOI 10.1002/14651858.CD008042.pub2, PMID 20393964). Six crossover studies. Exposures: zolmitriptan 5 mg n=231, zolmitriptan 10 mg n=223, sumatriptan 6 mg SC n=131, sumatriptan 12 mg n=88, sumatriptan 20 mg intranasal n=77, placebo n=430. Three studies scored 5/5 and three 4/5 on the Oxford quality scale; none was at high risk of bias.

Headline: NNT 2.4 for 15-minute pain relief with sumatriptan 6 mg SC (75% response).

Four limitations Cochrane flagged that remain unaddressed sixteen years later, and which map exactly onto real-world chronic use:

• No study reported recurrence data.
• No study used multiple dosing for a single attack.
• No study examined treatment before the attack reached moderate intensity.
• Washout periods were only 18–24 hours.

In other words: the trial literature has never studied the way chronic daily patients actually use this drug.

peer-reviewed Sumatriptan’s half-life is approximately 120 minutes (Leone & Proietti Cecchini 2016, PMC4731683).

1.2.2 Intranasal sumatriptan

peer-reviewed van Vliet JA, Bahra A, Martin V, Ramadan N, Aurora SK, Mathew NT, Ferrari MD, Goadsby PJ. “Intranasal sumatriptan in cluster headache: randomized placebo-controlled double-blind study.” Neurology. 2003;60(4):630–3 (PMID 12601104, DOI 10.1212/01.WNL.0000046589.45855.30). 5 centres, 118 patients, 154 attacks (77 per arm), attacks lasting ≥45 min, 20 mg intranasal.

Outcome at 30 min	Sumatriptan 20 mg IN	Placebo	p
Responder	57%	26%	0.002
Pain-free	47%	18%	0.003

No serious adverse events. Note the endpoint is 30 minutes, not 15 — nasal sumatriptan is meaningfully slower than subcutaneous, which matters when the median attack is under two hours and the peak is early.

1.2.3 Zolmitriptan

peer-reviewed Cittadini E, May A, Straube A, Evers S, Bussone G, Goadsby PJ. “Effectiveness of intranasal zolmitriptan in acute cluster headache: a randomized, placebo-controlled, double-blind crossover study.” Arch Neurol. 2006;63(11):1537–42 (PMID 16966497, DOI 10.1001/archneur.63.11.nct60002, ISRCTN27362692). 92 randomised (80 M / 12 F, mean age 40 ± 10), ITT 69.

Headache relief at 30 minutes:

Subgroup	Placebo	Zolmitriptan 5 mg	Zolmitriptan 10 mg
All patients	21%	40%	62%
Episodic CH	30%	47%	80%
Chronic CH	14%	28%	36%

Wald χ²(1) = 29.4, P < .001 overall.

This table is the single most important piece of information in this section for a chronic daily patient. Intranasal zolmitriptan 10 mg produces relief in 80% of episodic patients and 36% of chronic patients — barely more than double the chronic placebo rate. The headline “62%” figure quoted in guidelines and reviews is driven almost entirely by the episodic subgroup. If you have chronic CH and nasal zolmitriptan has underwhelmed you, you are not an outlier; you are the modal chronic patient in this trial.

peer-reviewed Rapoport AM, Mathew NT, Silberstein SD, Dodick D, Tepper SJ, Sheftell FD, Bigal ME. “Zolmitriptan nasal spray in the acute treatment of cluster headache: a double-blind study.” Neurology. 2007;69(9):821–6 (PMID 17724283, DOI 10.1212/01.wnl.0000267886.85210.37). 52 patients, 151 attacks, three-period crossover.

Outcome	Placebo	ZNS 5 mg	ZNS 10 mg
Headache response at 30 min	30%	50%	63.3%
Relief at 10 min	10%	—	24.5%
Pain-free at 15 min	6%	—	22.0%
Pain-free at 30 min	20%	38.5%	46.9%
Mild side effects	16%	25%	32.7%

peer-reviewed Bahra et al. 2000 studied oral zolmitriptan: 13 centres, 153 randomised, 123 in the efficacy analysis, mean age 44 ± 11, 86% men, 73% episodic (per Cochrane 2010). Oral triptans are consistently the weakest option and are the main reason self-reported triptan efficacy looks inconsistent in community surveys peer-reviewed (Rusanen et al. 2022).

Australian availability note: peer-reviewed intranasal zolmitriptan is not available in Australia (Aust Prescr 2022). For an Australian patient the practical acute drug menu is subcutaneous sumatriptan, intranasal sumatriptan, and oxygen.

1.2.4 Comparison table — acute drug efficacy

From the Australian Prescriber peer-reviewed summary table (Aust Prescr 2022;45:15–20) peer-reviewed:

Therapy	Dose / max per 24 h	Efficacy
Sumatriptan SC	6 mg; max 12 mg/24 h	Mild/no pain at 15 min 75% (placebo 32%); pain-free at 15 min 48% (17%)
Sumatriptan intranasal	20 mg; max 40 mg/24 h	Mild/no pain at 30 min 57% (26%); pain-free at 30 min 47% (18%)
Zolmitriptan intranasal 5 mg	max 20 mg/24 h	Mild/no pain at 30 min 45% (30%); pain-free at 30 min 32% (18%)
Zolmitriptan intranasal 10 mg	max 20 mg/24 h	Mild/no pain at 30 min 62% (30%); pain-free at 30 min 48% (18%)
High-flow oxygen	7–12 L/min, 15 min	Pain reduction at 15 min 78% (20%)
nVNS (episodic only)	3 stimulations × 2 min	Mild/no pain at 15 min 39% (12%)

Triptans may be repeated after two hours.

1.2.5 Dose limits and cardiovascular contraindications

peer-reviewed Official ceiling: 12 mg subcutaneous sumatriptan per 24 hours (two 6 mg injections). The NHS states no more than two injections, two nasal doses, or 300 mg of tablets per 24 hours (NHS, sumatriptan dosing). The WHO Essential Medicines List submission for CH (2025) specifies sumatriptan 6 mg/0.5 mL prefilled syringe or autoinjector, maximum 12 mg/day (WHO EML application).

Cross-cultural divergence worth knowing peer-reviewed: the Japanese Headache Society uses subcutaneous sumatriptan 3 mg, maximum 6 mg/day — half the Western dose and half the Western ceiling (WHO EML application); the JHS guideline refers to the insurance-covered frequency as twice daily (JHS CQ1). Japanese source. No source found explains whether the halved dose reflects pharmacogenomic differences, body mass, or regulatory conservatism. Unknown.

Contraindications peer-reviewed:

• Australian Prescriber lists ischaemic heart disease (Aust Prescr 2022).
• The Japanese guideline lists ischaemic heart disease, cerebrovascular disease, peripheral vascular disease; adverse effects nausea, chest discomfort, palpitations; and notes that “not a few patients cannot use it because self-injection is difficult” (「自己注射が困難で使用できない症例も少なくない」) (JHS CQ1). Japanese source — the needle-phobia point is rarely mentioned in Western guidelines but is a real limiter.
• The WHO submission specifies the same dose in elderly patients with added cardiovascular monitoring (WHO EML).

1.2.6 The chronic/daily problem — the central tension of this chapter

Set out the arithmetic. peer-reviewed The ICHD-3 diagnostic criterion permits attack frequency from one every other day up to eight per day (ICHD-3 criteria as reproduced in JHS CQ1; Aust Prescr 2022). The maximum permitted sumatriptan dose is two injections per day. A patient with four attacks per day is therefore formally under-treated by design for half of them, and a patient with eight is under-treated for three-quarters.

Guidelines do not resolve this. They mostly do not mention it.

What the real-world data actually shows

peer-reviewed Leone M, Proietti Cecchini A. “Long-term use of daily sumatriptan injections in severe drug-resistant chronic cluster headache.” Neurology. 2016;86(2):194–195 (PMC4731683, DOI 10.1212/WNL.0000000000002117, PMID 26475695). Istituto Neurologico Carlo Besta, Milan. Italian source — and the only systematic dataset on this question that exists.

• 53 consecutive chronic CH patients, 2003–2014, all using ≥2 subcutaneous sumatriptan injections per day for ≥2 years.
• All required the full 6 mg dose; none could manage on less.
• Patients “overdosed sumatriptan despite recommendations of their physicians.”
• A cited multicentre observation records a maximum of 36 mg in 24 hours — six times the labelled daily ceiling.
• No serious adverse events. No ECG abnormalities. No discontinuations.
• But: 42% noticed a subjective reduction in efficacy — longer latency to effect and less pain reduction over time.
• Sumatriptan nonetheless remained their first-choice treatment.
• Classified Class IV evidence (retrospective, uncontrolled).

peer-reviewed A cited 3-month prospective study of 138 CH patients treating 6,353 attacks with a maximum of two injections per day found no clinically significant ECG or laboratory effects (reported in Leone & Proietti Cecchini 2016).

peer-reviewed Case report, Headache (2011), PMID 22082424: a 49-year-old woman used subcutaneous sumatriptan for 15 years at daily doses of 12–222 mg, averaging 150 mg/day in the final year, with continued efficacy and “without adverse events.” This is a single case and should be read as such — it establishes possibility, not safety.

peer-reviewed Centonze V et al. Funct Neurol. 2000;15(3):167–70 (PMID 11062845), University of Bari, Italy. 13 episodic CH patients, all with more than three attacks per day, all exceeding the recommended dose for one year. No tolerance, no tachyphylaxis, no rebound, no dependence. Only 4 patients had minor adverse events — and those 4 all also had migraine without aura and a family history of migraine. Italian source. That last correlation is odd and unexplained; flagged as a minority observation, n=4.

peer-reviewed Brandt RB, Doesborg PGG, Haan J, Ferrari MD, Fronczek R. “Pharmacotherapy for Cluster Headache.” CNS Drugs. 2020;34(2):171–184 (PMC7018790, DOI 10.1007/s40263-019-00696-2, PMID 31997136) states the tension explicitly: “In daily practice, patients with cluster headache experiencing daily attacks use multiple sumatriptan injections per day for a long time. Official guidelines state that no more than two injections per day can be used.” The same review notes suicidal ideation in 55% of CH patients — relevant context for why patients exceed limits.

Reading this honestly

What the evidence supports: several independent groups (Milan, Bari, plus case reports) have observed chronic CH patients exceeding the 12 mg/day ceiling — sometimes grossly — over periods of years, without detecting serious cardiovascular events, ECG changes, tachyphylaxis or dependence.

What the evidence does not support: a conclusion that this is safe. Every one of those studies is retrospective, uncontrolled, small, and conducted in patients who had already self-selected by tolerating high doses. A patient who had a cardiac event on injection three would not be in the Milan cohort of long-term daily users. This is textbook survivorship bias, and it is the single most important caveat in this chapter.

What is genuinely established: peer-reviewed 42% of long-term daily users report declining efficacy (Leone & Proietti Cecchini 2016). Whatever the safety position, the drug appears to get less useful the more you rely on it.

Where community and guidelines diverge: citizen science the Clusterbusters survey found that “most comments about side effects and concerns were directed at triptans,” not oxygen (Schindler et al. 2018) — patients themselves are wary of triptans in a way the enthusiasm for high-dose use might not suggest. The community position is not “triptans are safe at any dose”; it is closer to “triptans are rationed too tightly and oxygen should carry the load.”

The practical resolution every credible source converges on

Use oxygen as the workhorse; reserve triptans for the attacks oxygen cannot hold.

This is stated most explicitly by the Japanese Headache Society, which frames oxygen reimbursement as the solution for “patients with frequent attacks for whom the insurance-approved twice-daily sumatriptan limit made adequate treatment difficult,” noting that oxygen “can be used many times a day” and “has no serious side effects” (JHS CQ1) peer-reviewed, Japanese source. EAN makes the same point structurally: oxygen has “no contraindications,” “no interactions,” and “can be used several times per day” (EAN 2023) peer-reviewed. Schindler’s survey supplies the empirical backing — at >10 L/min, oxygen 81.5% vs sumatriptan 80.5%, not significantly different citizen science (Schindler et al. 2018).

The second half of the resolution is effective prevention, because the triptan ceiling is only a crisis if attack frequency stays high. That is what the next section is about.