Triptan Therapy: There are seven Triptans available in Ireland.
- Almotriptan 12.5 mg orally
- Frovatriptan 2.5 mg orally
- Sumatriptan 50 mg / 100 mg orally; 20 mg/ 40 mg intranasally; mg subcutaneously (on a named patient basis)
- Zolmitriptan 2.5 mg orally (conventional and orally disintegrating formulation)
- Rizatriptan 5 mg / 10 mg orally (conventional and orally disintegrating formulation)
- Eletriptan 40 mg
- Naratriptan 2.5 mg
Meta-analysis has confirmed that although minor variations exist among the Triptans in terms of efficacy and tolerability, no one Triptan is substantially superior to another, especially in oral format. For reasons that are unclear, some patients respond better to one Triptan than another, so it is important to be familiar with them all as well as the different formulations available
Sumatriptan was the first Triptan to be approved for migraine abortive therapy. It is available in Ireland either orally or as a nasal spray. A subcutaneous formulation is available on a named-patient basis. The nasal spray has a faster onset of action than the oral preparation, while the injectable form has the fastest onset of action of all the triptans. Orally, Sumatriptan is available in 50 and 100 mg doses and the intranasal formulation is available in 20mg.
Frovatriptan is a long-duration Triptan with a half life of approximately 25 hours. It also has a lower headache recurrence rate than the other triptans. However, its onset of action is slower than that of the shorter-duration triptans. Frovatriptan may be best-suited for migraines that develop slowly and last longer. There is some evidence that frovatriptan is effective in preventing migraine associated with menstruation.
Available in a 12.5 mg dose, Almotriptan has few drug interactions and a low adverse event profile. It also has a low headache recurrence rate. The drug’s onset of action is similar to that of sumatriptan.
Zolmitriptan is available in two different preparations-oral tablets (2.5 mg and 5 mg) and the “melt” form (ODT), which dissolves when placed on the tongue. Zolmitriptan is absorbed quickly and has a long half-life.
Relpax comes in the the form of 40 mg tablets. Its most common side effects include dizziness, dry mouth and somnolence. Its manufacturer, Pfizer, claims that is more cost-effective than the four more established triptans.
Rizatriptan is available in both 5 mg and 10 mg capsule shaped tablets which are pink. They are also available in a format which dissolves in the mouth. They are manufactured by Merck, Sharp and Dohme (MSD) Ireland.
This is the newest Triptan to become available in Ireland. Its manufacturer, TEVA pharmaceuticals, claim that its low side effect profile and cost-savings make it a welcome addition to the triptans already available in Ireland. Tablets available in 2.5 mg.
The Migraine Association of Ireland
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Early Intervention is Necessary
Early intervention will often result in a more rapid reduction of headache pain and return to normal function. Treating headache early when the pain is milder will allow the patient to become pain-free within two hours in 80% of cases vs only 36% when a Triptan is used later in the attack when the pain is more severe.
Early intervention will also lessen the likelihood of headache recurrence and limit the drug’s side effects.
Treating a migraine swiftly may also reduce the patient’s risk of developing allodynia, a painful response to a non-painful stimulus. Patients with allodynia may experience peripheral pain in their scalp while combing their hair, or they may feel pain in an extremity as the headache pain intensifies. Triptans are more effective when used prior to the onset of allodynia.
Although up to 80% of patients will experience pain relief within two hours of taking a Triptan (four hours in the case of Frovatriptan), a second dose is advised if the headache has not improved in this time or if the headache resolves and then recurs within 24 hours. Headache recurrence occurs in about 30% or attacks. In these cases, further doses of the prescribed Triptan should be repeated. If a second dose is used, up to 90% of patients will have complete relief within four hours.
Despite their advantages, Triptans do not respond in all patients and in clinical practice it is not possible to predict who will or will not respond. Failure with one Triptan does not necessarily mean that the patient will not benefit from another in the family. An evaluation of each patient as to his or her clinical needs should drive the choice of Triptan. Evaluation of efficacy for a particular patient should be based over three consecutive attacks with the aid of a migraine diary.
Patients with Nausea
Although oral administration is the simplest, it may not be appropriate for many of the 70% of migraineurs who have associated nausea and vomiting When taken intranasally or subcutaneously, Triptan onset of action may be as fast as fifteen minutes. Alternatively, an oral Triptan can be taken with 10 mg metoclopramide to encourage absorption.
Medication-induced headaches can result from overuse of triptans but are less likely to result from triptans than analgesics or ergotamine. If a patient is taking a Triptan, more often than three days per week Triptan therapy should be discontinued and replaced by preventive therapy.
A Note on Ergotamine
Since Triptans have a more favourable side effect profile, they have now largely replaced ergotamine as a first line migraine treatment.
Ergotamine is a vasoconstrictor that specifically counteracts the dilation of some arteries and arterioles, primarily the branches of the external carotid artery. It has also been closely linked to Rebound Headache. For these reason, it can no longer be recommended as an alternative to the Triptans.