The clinical profile of sumatriptan: cluster headache

[Sumatriptan 3 mg subcutaneous : Clinical relevance of acute treatment of migraine despite dose reduction]

BACKGROUND

Triptans are a highly effective substance class in the acute treatment of migraine attacks. They contribute to a substantial improvement in the quality of life and help to reduce the socioeconomic burden of the disease.

RESULTS

Sumatriptan is the only triptan that is available for subcutaneous administration. It is primarily indicated in patients with the need for rapid relief or insufficient enteral resorption due to nausea and vomiting. In the treatment of migraine attacks with 6 mg subcutaneous sumatriptan the number needed to treat (NNT) is 2.3 for freedom from pain within 2 h and the NNT is 2.1 for pain relief within 2 h; however, the fast resorption of sumatriptan after subcutaneous administration induces more side effects than the oral route, for example dizziness, paresthesia or chest pressure sensation.

CONCLUSION

Clinical studies showed that reducing the subcutaneous dose to 3 mg in migraine treatment has significantly better tolerability with high response rates and freedom from pain within 2 h with 66.7% (3 mg) or 50% (6 mg).

Triptans for acute cluster headache

BACKGROUND

This is an updated version of the original Cochrane review published in Issue 4, 2010 (Law 2010). Cluster headache is an uncommon,severely painful, and disabling condition, with rapid onset. Validated treatment options are limited; first-line therapy includes inhaled oxygen. Other therapies such as intranasal lignocaine and ergotamine are not as commonly used and are less well studied. Triptans are successfully used to treat migraine attacks and they may also be useful for cluster headache.

OBJECTIVES

To assess the efficacy and tolerability of the triptan class of drugs compared to placebo and other active interventions in the acute treatment of episodic and chronic cluster headache in adult patients.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL),MEDLINE, EMBASE, ClinicalTrials.gov, and reference lists for studies from inception to 22 January 2010 for the original review, and from 2009 to 4 April 2013 for this update.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled studies of triptans for acute treatment of cluster headache episodes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data. Numbers of participants with different levels of pain relief,requiring rescue medication, and experiencing adverse events and headache-associated symptoms in treatment and control groups were used to calculate relative risk and numbers needed to treat for benefit (NNT) and harm (NNH).

MAIN RESULTS

New searches in 2013 did not identify any relevant new studies.All six included studies used a single dose of triptan to treat an attack of moderate to severe pain intensity. Subcutaneous sumatriptan was given to 131 participants at a 6 mg dose, and 88 at a 12 mg dose. Oral or intranasal zolmitriptan was given to 231 participants ata 5 mg dose, and 223 at a 10 mg dose. Placebo was given to 326 participants.Triptans were more effective than placebo for headache relief and pain-free responses. By 15 minutes after treatment with subcutaneous sumatriptan 6 mg, 48% of participants were pain-free and 75% had no pain or mild pain (17% and 32% respectively with placebo).NNTs for subcutaneous sumatriptan 6 mg were 3.3 (95% CI 2.4 to 5.0) and 2.4 (1.9 to 3.2) respectively. Intranasal zolmitriptan 10mg was of less benefit, with 12% of participants pain-free and 28% with no or mild pain (3% and 7% respectively with placebo).NNTs for intranasal zolmitriptan 10 mg were 11 (6.4 to 49) and 4.9 (3.3 to 9.2) respectively.

AUTHORS' CONCLUSIONS

Based on limited data, subcutaneous sumatriptan 6 mg was superior to intranasal zolmitriptan 5 mg or 10 mg for rapid (15 minute)responses, which are important in this condition. Oral routes of administration are not appropriate.

Triptans for acute cluster headache

BACKGROUND

Cluster headache is an uncommon, but severely painful and disabling condition, with rapid onset. Validated treatment options are limited, and first-line therapy includes inhaled oxygen. Alternative therapies such as intranasal lignocaine and ergotamine are not as commonly used and are less well studied. Triptans are successfully used to treat migraine attacks and, because of this, they may also be useful for cluster headache.

OBJECTIVES

To determine the efficacy and tolerability of triptans for the acute treatment of cluster headaches.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE and EMBASE for studies through 22 January 2010.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled studies of triptans for acute treatment of cluster headache episodes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data. Numbers of participants with different levels of pain relief, requiring rescue medication and experiencing adverse events and headache-associated symptoms in treatment and control groups were used to calculate relative risk and numbers needed to treat (NNT) and harm (NNH).

MAIN RESULTS

All six included studies used a single dose of triptan to treat an attack of moderate to severe pain intensity. In total 231 participants received zolmitriptan 5 mg, 223 received zolmitriptan 10 mg, 131 received sumatriptan 6 mg, 88 received sumatriptan 12 mg, and 326 received placebo. Zolmitriptan was administered either orally or intranasally, and sumatriptan either subcutaneously or intranasally.Overall, the triptans studied were better than placebo for headache relief and pain-free responses, with an NNT of 2.4 for 15 minute pain relief with subcutaneous sumatriptan 6 mg (75% with sumatriptan and 32% with placebo), and 2.8 for 30 minute pain relief with intranasal zolmitriptan 10 mg (62% with zolmitriptan and 26% with placebo). Fewer participants need rescue medication with triptan than with placebo, but more experienced adverse events.

AUTHORS' CONCLUSIONS

Zolmitriptan and sumatriptan are effective in the acute treatment of cluster headaches and may provide a useful treatment option, potentially offering convenience over oxygen therapy and a better safety and tolerability profile than ergotamine. Non-oral routes of administration are likely to provide better and more rapid responses.

Treatment-emergent CNS symptoms following triptan therapy are part of the attack

If treatment-emergent central nervous system (CNS) symptoms following triptan therapy represent direct pharmacological effects of the drug, they should occur independent of response to active drug. However, if they represent unmasking of neurological symptoms of the migraine attack after pain is relieved, they should be more common in responders both to active drug and to placebo. To explore this issue, we evaluated the relationship between the CNS adverse events and treatment response following triptan or placebo treatment. We used pooled data from seven double-blind, placebo-controlled trials involving eletriptan 20 mg (E20, n = 402), eletriptan 40 mg (E40, n = 1870), eletriptan 80 mg (E80, n = 1393), sumatriptan 100 mg (S100, n = 275) and placebo (Pbo, n = 1024). Somnolence was more prevalent among 2 h headache responders than non-responders for all treatments, including E80 (8.8% vs. 5.0%; P < 0.05), E40 (6.4% vs. 5.0%; NS), E20 (4.0% vs. 2.0%; NS), S100 (4.7% vs. 3.2%; NS) and Pbo (7.6% vs. 3.0%; P < 0.05). Similarly, the incidence of asthenia was higher among patients who responded to treatment compared with those who did not respond to E80 (15.2% vs. 7.8%; P < 0.05), E40 (6.5% vs. 3.6%; P < 0.05), E20 (6.5% vs. 1.0%; P < 0.05), S100 (10.1% vs. 4.7%; NS) and Pbo (4.4% vs. 2.7%; NS). The generally higher rates of somnolence and asthenia in patients who respond to treatment suggests that these treatment-emergent neurological symptoms may represent the unmasking of CNS symptoms associated with the natural resolution of a migraine attack, rather than simply representing drug-related side-effects. The rate of somnolence in placebo responders is comparable to that in responders to E40 and E80, indicating that somnolence is related, at least in some important part, to headache relief and not treatment.

Intracranial vessels in trigeminal transmitted pain: A PET study

The underlying principle in interpreting data from positron emission tomography (PET) is that increases and decreases of synaptic activity in the brain are accompanied by equivalent changes in regional blood flow. However, given the relatively low spatial resolution of PET, regional indices of neural activity can be influenced by signals from nonneural elements in the intracranial space. We have used PET to study the functional neuroanatomy of headache syndromes, such as cluster headache and experimental headache, by observing activation in brain that is due to synaptic activity. In these studies we noted a bilateral activation in midline structures over several planes that, based on its anatomy, is likely to arise from bilateral large intracranial arteries in the region of the cavernous sinus. We have observed this activity in two different group studies and in 11 of 17 single-subject studies. The most likely explanation for this "activation" is the increased volume of space occupied by dilated large vessels containing H215O. We further defined the anatomy of the PET findings using magnetic resonance angiography, which showed bilateral vasodilatation of the internal carotid artery and the basilar artery in nitroglycerin-induced cluster headache attacks. While the fact that vascular structures can contaminate PET-based blood flow studies may be well known to methodological experts, the issue is less well recognized outside the immediate field.

Inhibition of trigeminal neurones after intravenous administration of naratriptan through an action at 5-hydroxy-tryptamine (5-HT(1B/1D)) receptors

1. The observation that 5-hydroxytryptamine (5-HT) is effective in treating acute attacks of migraine when administered intravenously resulted in a research effort that led to the discovery of the 5-HT(1B/1D) receptor agonist sumatriptan. 2. Clinical experience has shown sumatriptan to be an effective treatment with some limitations, such as relatively poor bioavailability, which naratriptan was developed to address. Increasing bioavailability has been achieved with greater lipophilicity and thus the potential for greater activity in the central nervous system. 3. In this study the increased access to central sites has been exploited in an attempt to characterize the pharmacology of those central receptors with the newer tools available. Trigeminovascular activation was examined in the model of superior sagittal sinus stimulation. 4. Cats were anaesthetized with alpha-chloralose (60 mg kg(-1), intraperitoneal), paralyzed (gallamine 6 mg kg(-1), intravenously) and ventilated. The superior sagittal sinus was accessed and isolated for electrical stimulation (250 micros pulses, 0.3 Hz, 100 V) by a mid-line circular craniotomy. The region of the dorsal surface of C2 spinal cord was exposed by a laminectomy and an electrode placed for recording evoked activity from sinus stimulation. 5. Stimulation of the superior sagittal sinus resulted in activation of cells in the dorsal horn of C2. Cells fired with a probability of 0.69+/-0.1 at a latency of 9.2+/-0.2 ms. Intravenous (i.v.) administration of naratriptan at clinically relevant doses (30 and 100 microg kg(-1)), inhibited neuronal activity in trigeminal neurones of the C2 dorsal horn, reducing probability of firing without affecting latency. 6. The effect of naratriptan could be reversed by administration of the selective 5-HT(1B/1D) receptor antagonist GR127935 (100 microg kg(-1), i.v.). 7. These data establish that naratriptan acts on central trigeminal neurones since sagittal sinus stimulation activates axons within the tentorial nerve and there are no inhibitory effects mediated within the trigeminal ganglion. Furthermore, given that this inhibition could be reversed by the relatively selective 5-HT(1B/1D) receptor antagonist GR127935, it is highly likely that the anti-migraine effects of drugs of this class with central nervous system access are mediated, at least in part, by 5-HT(1B/1D) receptors within the trigeminal nucleus.

Pearls, pitfalls, and updates for pain management

Pain management is one of the most challenging areas we encounter as emergency physicians. However, many of us fail to adequately meet this challenge. This article discusses frequently encountered pain syndromes and pain management options.

Secondary cluster headache responsive to sumatriptan

A patient was seen with secondary cluster headache whose acute pain responded promptly to sumatriptan. The headaches started after injury to the vertebral artery. This finding provides clinical affirmation of the existence of the trigeminal/cervical nuclear overlap that is central to this condition.