Headache Recurrence and Treatment

Variability in recurrence rates with acute treatments for migraine: why recurrence is not an appropriate outcome measure

BACKGROUND

Headache recurrence is a common feature of acute therapies, whether approved or still in development, and continues to be a significant problem for both the patient and the clinician. Further complicating this issue is lack of standardization in definitions of recurrence used in clinical trials, as well as disparity in patient characteristics, rendering a comparison of different acute medications challenging. Recurrence has serious clinical implications, which can include an increased risk for new-onset chronic migraine and/or development of medication overuse headache. The aim of this review is to illustrate variability of recurrence rates depending on prevailing definitions in the literature for widely used acute treatments for migraine and to emphasize sustained response as a clinically relevant endpoint for measuring prolonged efficacy. BODY: A literature search of PubMed for articles of approved acute therapies for migraine that reported recurrence rates was performed. Study drugs of interest included select triptans, gepants, lasmiditan, and dihydroergotamine mesylate. An unpublished post hoc analysis of an investigational dihydroergotamine mesylate product that evaluated recurrence rates using several different definitions of recurrence common in the literature is also included. Depending on the criteria established by the clinical trial and the definition of recurrence used, rates of recurrence vary considerably across different acute therapies for migraine, making it difficult to compare results of different trials to assess the sustained (i.e., over a single attack) and the prolonged (i.e., over multiple attacks) efficacy of a particular study medication.

CONCLUSION

A standardized definition of recurrence is necessary to help physicians evaluate recurrence rates of different abortive agents for migraine. Sustained pain relief or freedom may be more comprehensive efficacy outcome measures than recurrence. Future efficacy studies should be encouraged to use the recommended definition of sustained pain freedom set by the International Headache Society.

Why pharmacokinetic differences among oral triptans have little clinical importance: a comment

Triptans, selective 5-HT1B/1D receptor agonists, are specific drugs for the acute treatment of migraine that have the same mechanism of action. Here, it is discussed why the differences among kinetic parameters of oral triptans have proved not to be very important in clinical practice. There are three main reasons: (1) the differences among the kinetic parameters of oral triptans are smaller than what appears from their average values; (2) there is a large inter-subject, gender-dependent, and intra-subject (outside/during the attack) variability of kinetic parameters related to the rate and extent of absorption, i.e., those which are considered as critical for the response; (3) no dose-concentration–response curves have been defined and it is, therefore, impossible both to compare the kinetics of triptans, and to verify the objective importance of kinetic differences; (4) the importance of kinetic differences is outweighed by non-kinetic factors of variability of response to triptans. If no oral formulations are found that can allow more predictable pharmacokinetics, the same problems will probably also arise with new classes of drugs for the acute treatment of migraine.

Cost-effectiveness analysis of rizatriptan and sumatriptan versus Cafergot in the acute treatment of migraine

BACKGROUND

Both ergotamine and selective serotonin 5-HT(1B/1D) receptor agonists ('triptans') are currently used in the treatment of moderate to severe migraine. Ergotamine is a traditional therapy with a lower drug acquisition cost compared with triptans. It has been shown that triptans are more efficacious than ergotamine, but the higher acquisition costs and shorter duration of action are disadvantages of triptans compared with ergotamine.

OBJECTIVE

The purpose of this study was to provide a comparison of the cost-effectiveness of rizatriptan 10 mg and sumatriptan 50 mg tablets with that of a fixed-dose combination of ergotamine tartrate plus caffeine (Cafergot) in the treatment of an acute migraine attack. The cost-effectiveness of rizatriptan in comparison with sumatriptan was also assessed.

METHODS

Three separate decision tree models were developed (model 1: rizatriptan vs Cafergot; model 2: sumatriptan vs Cafergot; model 3: rizatriptan vs sumatriptan). The time horizon was 1 year. Cost-effectiveness analysis was conducted from the societal perspective using cost and effectiveness estimates from the literature. All costs were converted to US dollars (2003). The cost-effectiveness ratio was expressed as incremental cost per quality-adjusted life-year (QALY) gained.

RESULTS

Base case evaluation showed that both rizatriptan and sumatriptan dominated Cafergot. The net annual saving associated with use of rizatriptan was US dollars 622.98 per patient, with an incremental QALY of 0.001. Use of sumatriptan resulted in a saving of US dollars 620.90 and an increase in QALY. The cost-effective ratios were not sensitive to changes in key variables such as efficacy, utility, drug costs, hospitalisation cost and patient preference over alternative therapies. The study further showed that rizatriptan is more cost effective than sumatriptan, as evidenced by its lower cost and greater effectiveness. Sensitivity analysis showed that the cost-effectiveness ratios were sensitive to moderate changes in drug efficacy.

CONCLUSION

Rizatriptan and sumatriptan were less costly and more effective than Cafergot in the treatment of an acute migraine attack. Rizatriptan was somewhat less costly and more effective than sumatriptan. Additional quality-of-life studies are needed to confirm the benefits of using triptans in the management of migraine.