Choosing the Right Triptan
Five years have elapsed since the advent of triptan options as the treatment of choice for migraine.1,2 With the vast clinical experience gained over this period, it is useful to review triptan delivery, efficacy, and dosage for the wide variety of migraine presentations.
There are currently six triptans available on the US market. They are — in the order of their introduction — Imitrex, Maxalt, Zomig, Axert, Frova, and Amerge. Available dosages and manufacturers are listed in Table 1.
Available in Europe, and possibly soon in the U.S., is eletriptan in 80mg tablets from Pfizer.
With the notable exception of Imitrex nasal spray and Imitrex injectable, which have an increased percentage of efficacy over any pill, the efficacy rates between all of the pills — comparing dose to dose — are roughly the same with only minor variation. In general, when one combines most of the studies done on various triptans in comparing equal doses of the oral agents, they all seem to work in the 40 to 60% range. While most triptans seem to work with statistically equal efficacy, there does seem to be a variance in the individual preference for triptans.
The triptan class contains three categories: the ultra fast or immediate acting, the fast acting, and the slow acting/long lasting triptans (see Table 2).
Imitrex injectable is the only ultra-fast acting triptan and has a 70% response rate. The fast acting triptans are the traditional triptans: Imitrex tablet and nasal spray, Maxalt, Zomig, and Axert. The slow acting/long lasting triptans are Amerge and Frova. We now have a wide range of treatment options for the many presentations of migraine. Imitrex injectable is for the migraine that needs to be stopped as quickly and completely as possible. Frova and Amerge are for the long lasting migraine and the traditional triptans for the rest.
Following are discussions of clinical observations for each of the triptans identified above.
Imitrex has the advantage of coming with the most widely diverse dosage forms and delivery systems. The nasal spray and the injectable offer alternatives for the nauseated or migraine patient with actual emesis. There is certainly no doubt that the subcutaneous form of Imitrex is the triptan that works the quickest and is most generally effective. It has a 70% efficacy at a one hour response rate compared to a two-hour response rate for all the others. Another advantage is that you can move between the dosage forms. There is allowance for individual migraine variation between individual patients. For instance, one can use an Imitrex tablet for mild headaches or headaches having slow onset with the option of switching to an Imitrex nasal spray if the headache onset accelerates or has more nausea associated with it. Imitrex injectable can be used if the headache is coming on rapidly, the patient is vomiting, or if a break-through headache occurs with tablet use. When Imitrex pill or nasal spray is used as a starting dose, Imitrex allows the option of a follow-up with Imitrex injectable in the event that the headache does not respond or worsens. Note however that the FDA has not approved mixing Imitrex injectable with any other triptan so that Imitrex injectable is not an option if a different triptan was used as the starting dose. The only option in this case is to utilize medication outside of the triptan class. Disadvantages of Imitrex include side effects and recurrence rate. The side effects, however, typically last only 30 minutes. The Imitrex pill has a 40% chance of side effects, which is greater than other triptans with the exception of eletriptan 80 mg. The recurrence rate of the Imitrex injection is 35-50% and for the Imitrex oral is 25-40%. Table 3 summarizes the advantages/disadvantages of Imitrex.
|Imitrex (sumatriptan) tablets||Glaxo-Smith Kline||25mg, 50mg and 100mg
5mg and 20mg nasal spray
6 mg subcutaneous injectable
|Maxalt (rizatriptan)||Merck||5mg or 10mg tablets
|Zomig (zolmitriptan)||Astra Zeneca||2.5mg and 5mg tablets
orally- dissolving tablet
|Axert (almotriptan)||Pharmacia||6mg and 12.5mg tablets|
|Frova (frovatriptan)||Elán||2.5mg tablets|
|Amerge (naratriptan)||Glaxo Wellcome||1mg and 2.5 mg tablets|
|Immediate acting/ultra fast Injectable||Quick onset; severe||pain Imitrex|
|Fast acting||Moderate onset; moderate pain||Imitrex nasal/oral
|Slow onset/long acting||Slow onset; long duration; menstrual; prodrome||Frova
Maxalt does show some evidence of having a somewhat quicker onset of action than Zomig and Imitrex oral. (Some response at 30 minutes) However, it is still much slower than the Imitrex injectable. This may be due to its quicker Tmax. This, however, may lead to a greater incident of headache recurrence. All triptans combined have a recurrence rate of 20-45%, while Maxalt has a 29-47% recurrence rate.3 There is some confusion surrounding the oral dissolving preparation. Some physicians and patients think it is absorbed in the buccal surface and has a faster onset. Actually both the orally absorbing tablet and the pill are absorbed through the GI tract. There is some evidence that the orally dissolving tablet has a slower onset of action than the non-dissolving tablet. The benefit of the melt tablets is convenience. It is easier to use if the patient is nauseated or does not have water available to follow the pill. Of interest is that sniffing with the Imitrex nasal spray, while also contributory to the bad taste effect, changes the absorption to the GI route. This slows the onset of efficacy compared to the nasal route. Table 4 summarizes the advantages/disadvantages of Maxalt.