Advances in pharmacological treatment of migraine

Migraine: an endemic disease inside the blood–brain barrier

Migraine is a complex neurological disorder that in recent years has received more and more attention. Knowledge regarding this primary headache has increased substantially, both with respect to its pathogenesis and how to effectively treat its symptoms. Over the years, the proposed location of the onset of migraine has moved from the periphery of the nervous system toward deeper parts of the brain. Migraine can be viewed as an inherited failure of trigeminal sensory processing with abnormal neuronal excitability in the trigeminal nucleus caudalis, which, in turn, causes central sensitization and amplification of the pain. Increased activation of the trigeminal nerve during a migraine attack causes release of the calcitonin gene-related peptide (CGRP) inside and outside the BBB. Within the CNS, CGRP promotes trigeminal sensory input and facilitates central sensitization. The future introduction of CGRP antagonists in clinical practice could represent significant progress for acute migraine therapy.

Fixed-dose sumatriptan and naproxen in poor responders to triptans with a short half-life

OBJECTIVE

To evaluate efficacy and tolerability of a single, fixed-dose tablet of sumatriptan 85 mg/naproxen sodium 500 mg (sumatriptan/naproxen sodium) vs placebo in migraineurs who had discontinued treatment with a short-acting triptan because of poor response or intolerance.

BACKGROUND

Triptan monotherapy is ineffective or poorly tolerated in 1 of 3 migraineurs and in 2 of 5 migraine attacks. In April, 2008, the Food and Drug Administration approved the combination therapy sumatriptan/naproxen sodium, developed specifically to target multiple migraine mechanisms. This combination product offers an alternative migraine therapy for patients who have reported poor response or intolerance to short-acting triptans.

METHODS

Two replicate, randomized, multicenter, double-blind, placebo-controlled, 2-attack crossover trials evaluated migraineurs who had discontinued a short-acting triptan in the past year because of poor response or intolerance. Patients were instructed to treat within 1 hour and while pain was mild.

RESULTS

Patients (n = 144 study 1; n = 139 study 2) had discontinued an average of 3.3 triptans before study entry. Sumatriptan/naproxen sodium was superior (P < .001) to placebo for 2- through 24-hour sustained pain-free response (primary end point) (study 1, 26% vs 8%; study 2, 31% vs 8%) and pain-free response 2 hours post dose (key secondary end point) (study 1, 40% vs 17%; study 2, 44% vs 14%). A similar pattern of results was observed for other end points that evaluated acute (2- or 4-hour), intermediate (8-hour), or 2- through 24-hour sustained response for migraine (ie, pain and associated symptoms), photophobia, phonophobia, or nausea (with the exception of nausea 2 and 4 hours post dose). The percentage of patients with at least 1 adverse event (regardless of causality) was 11% with sumatriptan/naproxen sodium compared with 4% with placebo in study 1 and 9% with sumatriptan/naproxen sodium compared with 5% with placebo in study 2. Only 1 adverse event in 1 study was reported in > or =2% of patients after treatment with sumatriptan/naproxen sodium and reported more frequently with sumatriptan/naproxen than placebo: chest discomfort was reported in 2% of subjects in study 1, and no events met this threshold in study 2. No serious adverse events attributed to study medication were reported in either study.

CONCLUSION

In migraineurs who reported poor response to a short-acting triptan, sumatriptan/naproxen sodium was generally well tolerated and significantly more effective than placebo in conferring initial, intermediate, and sustained efficacy for pain and migraine-associated symptoms of photophobia and phonophobia.

Pathways to the Best Fit of Triptans for Migraine Patients

Variability in drug response is a major barrier to the successful treatment of migraine, and most treatments are only optimal in a subset of patients. Although triptans provide the best therapeutic option for the treatment of acute migraine, it has not previously been possible to predict how well patients will respond to a specific triptan or whether they will experience unpleasant adverse events. Hence, it has been difficult for physicians to match individual patients with the most suitable agent to treat their migraine pain. Intrapatient variability has been associated with polymorphisms in genes encoding drug-metabolizing enzymes, drug transporters and drug targets. Pharmacogenetics provides the possibility of tailoring the therapeutic approach to individual patients, in order to maximize treatment efficacy while minimizing the potential for unwanted side-effects. This review demonstrates how almotriptan may overcome genetically determined responses by utilizing diverse metabolic pathways to provide therapeutic benefit to many migraineurs.

Early Treatment in Migraine: How Strong is the Current Evidence?

Over the last 10 years, triptans (serotonin 5-HT1B/1D receptor agonists) have proved to be efficacious in treating migraine pain. However, recent evidence suggests that patients are still not receiving optimal pain management, particularly in clinical trials, where triptan treatment is generally not initiated until pain has reached moderate intensity. Pathophysiological evidence indicates that if treatment is initiated at an early stage, while pain is still mild and before the onset of central sensitization, outcomes for patients may be improved. In addition, a small number of clinical trials have been reported in which triptans were taken early (within 1 h of pain onset) or while pain was still mild; although constraints of trial design and data analysis limit definite conclusions, overall the results suggest that this early/mild approach results in more rapid and sustained pain relief. New studies are therefore needed to clarify the clinical benefits of early treatment, whilst taking into account potential risks, such as medication overuse. Ultimately, migraine treatment strategies require optimization in order to meet patient expectations and to reduce the current burden of migraine-associated disability.

Consistent Efficacy, Tolerability, and High Levels of Satisfaction With Almotriptan 12.5 mg When Used to Treat Multiple Migraine Attacks in Routine Clinical Practice

OBJECTIVE

To assess the efficacy, tolerability, and patient satisfaction with almotriptan 12.5 mg across multiple migraine attacks in routine clinical settings.

BACKGROUND

The efficacy and tolerability of almotriptan have been well-documented in clinical trials. Less information is available about patient acceptance of therapy under normal prescribing conditions in routine practice.

METHODS

This was a prospective, open-label surveillance study conducted on 899 adults with documented attacks fulfilling the IHS criteria for migraine in medical practices of 307 neurologists and primary care physicians across Germany from June 2001 to April 2002. Patients were eligible for inclusion in the study if they were being treated for the first time with almotriptan. Main outcome measures were pain relief, pain free, consistency, tolerability, and satisfaction with almotriptan 12.5 mg when used to treat multiple migraine attacks.

RESULTS

A total of 899 patients with migraine treated 1 (18.4%), 2 (25.9%), or 3 (55.6%) migraine attacks with almotriptan for a total of 2131 attacks. Pain relief at 2 hours was achieved in 84.5% of attacks; pain free was achieved in 41.4%. Consistency of almotriptan 12.5 mg (at least 2 out of 3 attacks successfully treated) was 87.3%. Most patients (88.5%) indicated that they were "satisfied" or "very satisfied" with their treatment with almotriptan and 80.3% of patients expressed that almotriptan 12.5 mg therapy was better than their prior therapy. Physicians' global assessment of the efficacy of almotriptan 12.5 mg was judged to be "good" and "very good" in 87.6% of the patients, and tolerability was considered to be "good" and "very good" in 96.3% of patients. More than 92% of physicians indicated that they would continue to prescribe almotriptan for their patients.

CONCLUSION

The high levels of efficacy, consistency, and tolerability of almotriptan 12.5 mg observed in this postmarketing surveillance study are not only consistent with the findings of controlled clinical trials but also resulted in high rates of patient and physician satisfaction with almotriptan and patient preference for almotriptan over prior acute treatments, including other triptans.

A double-blind, randomized, placebo-controlled, single-dose study of the cyclooxygenase-2 inhibitor, GW406381, as a treatment for acute migraine

The objective of the present study was to explore the clinical efficacy and tolerability of GW406381, a cyclooxygenase-2 (COX-2) inhibitor with relatively high CNS penetration, in acute migraine. This was a double-blind, single-dose study of GW406381 compared with placebo and naproxen sodium compared with placebo (protocol number CXA20008). Three hundred and thirty-seven subjects were randomized 1:1:1 to GW406381 (70 mg), naproxen sodium (825 mg), or placebo for the treatment of one migraine headache of moderate or severe intensity in a potential 8-week period. The primary end-point was the proportion of subjects with headache relief [reduction in headache severity score from pre-dose 2 (moderate) or 3 (severe) to 0 (no pain) or 1 (mild)] at 2 h post-dose for GW406381 compared with placebo. Significantly higher proportions of subjects treated with GW406381 (50%, P = 0.032) or naproxen sodium (56%, P = 0.005) than with placebo (35%) reported headache relief at 2 h post-dose. Additional significant benefits were observed on many secondary outcomes, including proportions of subjects pain-free, for both GW406381 and naproxen sodium treatment compared with placebo. Both active treatments were well tolerated. Single-dose GW406381 (70 mg) and naproxen sodium (825 mg) were effective and well tolerated in the treatment of acute migraine.

Meta-analysis examining the efficacy and safety of almotriptan in the acute treatment of migraine

OBJECTIVE

To evaluate the comparative efficacy and safety of oral almotriptan in treating acute migraine attacks.

BACKGROUND

Almotriptan is an oral selective sertonin(1B/1D) receptor agonist (triptan) with a high bioavailability and short half-life, developed for the treatment of migraine. In recent years, a number of randomized controlled trials have been published examining the efficacy and safety of almotriptan in the acute treatment of migraine.

METHODS

Systematic review and meta-analysis of randomized controlled trials (RCTs) using a random-effects model to estimate the pooled rate ratios (RRs) and 95% confidence intervals (95%CI) for the proportions of patients achieving headache relief and pain-free responses at 1 or 2 hours post-dose, sustained pain-free response at 2-24 hours post-dose, and safety outcomes (proportions of patients experiencing any adverse events, dizziness, somnolence, asthenia, and chest tightness) comparing almotriptan against placebo, other triptans, and different dosages of almotriptan. Absolute rate differences (ARDs) for 2-hour headache relief, pain free, and sustained pain free responses between almotriptan and placebo were also calculated.

RESULTS

Eight RCTs involving 4995 patients were included in the analysis. Almotriptan 12.5 mg was significantly more effective than placebo for all efficacy outcomes (RRs ranged from 1.47 to 2.15; ARDs ranged from 0.01 to 0.28) and there were no significant differences in any of the safety outcomes. There were also no significant differences in efficacy outcomes comparing almotriptan 12.5 mg against sumatriptan 100 mg and zolmitriptan 2.5 mg, but almotriptan 12.5 mg was associated with significantly fewer adverse events than sumatriptan 100 mg (RR: 0.39, 95%CI: 0.23, 0.67). However, there was no significant difference between almotriptan and sumatriptan in terms of clinically important adverse effects, such as dizziness, somnolence, asthenia, and chest tightness. Almotriptan 12.5 mg was significantly less effective than almotriptan 25 mg for 1-hour pain-free response (RR: 0.45, 95%CI: 0.21, 0.95), but associated with significantly fewer patients experiencing adverse events (RR: 0.61, 95%CI: 0.41, 0.91) than almotriptan 25 mg.

CONCLUSIONS

Almotriptan 12.5 mg is an effective treatment for acute attacks of migraine, in particular, it has been found to be as effective as sumatriptan 100 mg and zolmitriptan 2.5 mg. The risk of adverse events associated with almotriptan 12.5 mg was similar to placebo and significantly lower than sumatriptan 100 mg. Further research is required to assess the comparative efficacy of almotriptan against other triptans.

Meta-analysis of the efficacy and safety of zolmitriptan in the acute treatment of migraine

OBJECTIVE

To assess the relative efficacy and safety of zolmitriptan in the treatment of acute migraine attacks.

BACKGROUND

Zolmitriptan is a second-generation triptan developed for the treatment of migraine. Numerous randomized controlled trials (RCTs) have been carried out to compare different dosages and formulations of zolmitriptan against other treatments for acute migraine.

METHODS

Random effects meta-analysis of 24 RCTs, including 15,408 patients suffering from acute migraine attacks. Subgroup analyses compared differences in response between different dosages and formulations of zolmitriptan, and other triptan comparators.

RESULTS

Zolmitriptan 2.5 mg tablet was found to be as effective as almotriptan 12.5 mg, eletriptan 40 mg, sumatriptan 50 mg and 100 mg and more effective than naratriptan 2.5 mg in terms of 2-hour pain-free rates. Likewise, zolmitriptan 5 mg tablet was as effective as sumatriptan 50 mg and 100 mg in 2-hour pain-free rates. Compared against zolmitriptan 2.5 mg tablet, eletriptan 80 mg was more effective in achieving headache relief, pain-free and sustained pain-free responses, and rizatriptan 10 mg was more effective in terms of sustained pain-free rates. Zolmitriptan 2.5 mg tablet was associated with a lower risk of adverse events than eletriptan 80 mg but higher risk than naratriptan 2.5 mg and rizatriptan 10 mg. Zolmitriptan 5 mg tablet was superior to zolmitriptan 2.5 mg tablet in achieving 1- and 2-hour pain-free response. There were no significant differences in 1- and 2-hour headache relief and adverse event rates between the different formulations of zolmitriptan 2.5 mg.

CONCLUSIONS

Zolmitriptan 2.5 mg tablet is an effective treatment for acute attacks of migraine showing similar efficacy to almotriptan 12.5 mg, eletriptan 40 mg, and sumatriptan 50 mg, and being more effective than naratriptan 2.5 mg in terms of pain-free response at 2 hours post dose. Zolmitriptan 2.5 mg tablet was also as effective as rizatriptan 10 mg in terms of headache relief and pain-free response but less effective in terms of sustained pain-free response.

5-hydroxytryptamine1B receptor and triptan response in migraine, lack of association with common polymorphisms

Triptans mediate vasoconstriction of meningeal vessels via stimulation of vascular 5-hydroxytryptamine (5-HT)(1B) receptors. These drugs are recommended for acute treatment in patients with moderate-to-severe migraine attacks and in those patients with mild-to-moderate headache that are not controlled adequately by other agents. Yet, approximately 25% of all migraine users and 40% of all attacks do not respond to triptan treatment. Among the hypothesis to explain this is the possibility that genetic single nucleotide polymorphisms that alter the receptor, for example changing the transcriptional rate and therefore the amount of target protein might change the clinical response to these drugs. In the present contribution, we therefore decided to evaluate whether single nucleotide polymorphisms on the 5-HT(1B) gene might contribute to inter-individual variability in clinical responses to triptans. Two polymorphisms in the promoter region of the 5-HT(1B) receptor (T-261G and A-161T) and the synonymous variation G861C in the coding region were genotyped by restriction fragment length polymorphism in 105 migraine patients. In our sample population, 71% of patients responded to triptans. Allelic and diplotype frequencies were not significantly different between responders and non-responders. On the other hand, extrapolation of in vitro data on promoter activity would suggest that patients with higher copy number of receptors respond slightly better. Our data therefore do not support the involvement of 5-HT(1B) single nucleotide polymorphisms in mediating the inter-individual variability to triptans.

Use of almotriptan in triptan-experienced and triptan-naïve patients

OBJECTIVE

To evaluate the efficacy of oral almotriptan 12.5 mg as an acute treatment for migraine with a focus on triptan-experienced versus triptan-naïve patients.

RESEARCH DESIGN AND METHODS

Four recent Almirall-sponsored clinical trials of oral almotriptan 12.5 mg in acute migraine, in which data regarding previous acute therapy were collected, are reviewed. The results and conclusions are limited by the open-label and post hoc design of some of these trials and analyses.

RESULTS

In two trials, almotriptan 12.5 mg was used to treat migraine sufferers who were dissatisfied with or were receiving inadequate results with their previous therapy. One of these trials enrolled only patients whose dissatisfaction with their current therapy was confirmed by a validated questionnaire; the other looked at almotriptan 12.5 mg efficacy in patients with previous poor response to sumatriptan. In the other two trials, patients had been achieving satisfactory results with their migraine therapy; one was a randomized, double-blind clinical trial of almotriptan 12.5 mg and zolmitriptan 2.5 mg, the other was an open-label almotriptan 12.5 mg satisfaction trial. Almotriptan 12.5 mg is shown to be effective, well-tolerated, and preferred to previous agents in both patients who were satisfied with, and those who were dissatisfied with, their previous therapy.

CONCLUSIONS

Almotriptan should, therefore, not only be considered as first-line therapy for acute migraine but should also be considered for patients who are not satisfied with or not receiving optimal relief from their current acute therapy.

A pharmacogenomic evaluation of migraine therapy

Migraine is a common idiopathic primary headache disorder with significant mental, physical and social health implications. Accompanying an intense unilateral pulsating head pain other characteristic migraine symptoms include nausea, emesis, phonophobia, photophobia and in approximately 20-30% of migraine cases, neurologic disturbances associated with the aura phase. Although selective serotonin (5-HT) receptor agonists (i.e., 5-HT(1B/1D)) are successful in alleviating migrainous symptoms in < or = 70% of known sufferers, for the remaining 30%, additional migraine abortive medications remain unsuccessful, not tested or yet to be identified. Genetic characterization of the migrainous disorder is making steady progress with an increasing number of genomic susceptibility loci now identified on chromosomes 1q, 4q, 5q, 6p, 11q, 14q, 15q, 17p, 18q, 19p and Xq. The 4q, 5q, 17p and 18q loci involve endophenotypic susceptibility regions for various migrainous symptoms. In an effort to develop individualized pharmacotherapeutics, the identification of these migraine endophenotypic loci may well be the catalyst needed to aid in this goal. In this review the authors discuss the present treatment of migraine, known genomic susceptibility regions and results from migraine (genetic) association studies. The authors also discuss pharmacogenomic considerations for more individualized migraine prophylactic treatments.

Effect of Pain Intensity and Time to Administration on Responsiveness to Almotriptan: Results from AXERT® 12.5 mg Time Versus Intensity Migraine Study (AIMS)

OBJECTIVE

To determine whether time-based early treatment, independent of pain intensity, is superior to a pain intensity-based treatment, where patients are asked to treat at least moderate intensity headaches, resulting in a reduction of overall migraine headache duration.

BACKGROUND

Retrospective and prospective trials have reported improved outcomes when triptans were used early or to treat mild migraine headache pain. However, tolerability as well as efficacy may be 2 of several key issues that have prevented this new treatment paradigm from becoming universally accepted.

METHODS

In this multicenter, open-label, cluster-randomized study, patients with IHS-defined migraine were instructed to treat 2 sequential migraine headaches with almotriptan 12.5 mg using either Early Treatment (ET, ie, treat at earliest onset of headache pain, within 1 hour) or Standard Treatment (ST, ie, treat when headache pain intensity is moderate or severe). The novel trial design uses total migraine headache pain duration as the primary endpoint.

RESULTS

Results are presented for the first headache and include an ITT population of 757 ET and 693 ST patients. Median headache duration (time from onset of headache pain until no pain) was significantly shorter in ET patients compared to ST patients (3.18 vs 5.53 hours, P < .001). An analysis of the ET subgroup treating headache pain within 1 hour of onset revealed pain intensity, ie, treating mild or moderate versus severe pain, was significantly correlated with treatment outcomes defined by total headache duration, 2-hour pain free, sustained pain free, and use of rescue medication. Multivariate analyses comparing ST subgroups that treated within 1 hour versus greater than 1 hour after headache onset, demonstrate that both pain intensity, ie, treating moderate versus severe headache pain, and treating early versus late, were significantly correlated with total headache duration, 2-hour pain free, sustained pain free, and use of rescue medication. The overall incidence of adverse events was low; nausea and dizziness were the only adverse events with an incidence > or =1% in either treatment group (nausea: 2.5% and 1.7% and dizziness 1.1% and 0.7%, in the ET and ST groups, respectively).

CONCLUSION

Total headache duration was significantly shorter in the early treatment group compared to the standard treatment group. Considering time to treatment within a relatively early range of 1 hour or less, efficacy results when treating mild versus moderate pain were similar and both were associated with better outcomes than treatment of severe pain. When considering the prognostic variables of time to treatment and headache pain intensity (limited to moderate vs severe), both were independent predictors, with time to treatment a better predictor of headache duration and rescue medication use, and pain intensity a better predictor of 2-hour pain free and sustained pain free.

Evaluation of Efficacy, Tolerability, and Treatment Satisfaction with Almotriptan in 3 Consecutive Migraine Attacks

The objective of the open-label, multicenter Migraine--Satisfaction with Treatment: Reality with Almogran study was to assess efficacy, tolerability, and satisfaction with almotriptan 12.5 mg among migraineurs who were not achieving adequate results with their current acute therapy. Data from 434 patients (342 evaluable), were obtained for 929 attacks by 154 neurologists in France. Using a questionnaire developed by the National Agency for Accreditation and Evaluation in Health (ANAES), almotriptan was associated with an increased proportion of patients experiencing significant relief at 2 h (69.3 vs. 26.6%), tolerating the medication well (91.2 vs. 76.0%), able to resume activities (70.5 vs. 24.9%), and taking only 1 dose (59.4 vs. 28.1%) compared with previous therapies. At 2 h, headache pain had disappeared in 33.4% of attacks and was mild in 26.9%. Recurrence rate was 28.4% and rescue analgesics were used in 20.9% of attacks. The rate of adverse event-related discontinuations was 2.6%. The proportion of patients who were very satisfied/satisfied overall with almotriptan treatment was 69%. Almotriptan 12.5 mg was effective, well-tolerated and associated with a high rate of treatment satisfaction in patients whose previous acute migraine therapy was inadequate according to the ANAES recommendations.

Review of clinical trials using early acute intervention with oral triptans for migraine management

Most of the data on triptan use are from clinical trials in which patients were instructed to wait until migraine headache pain was moderate/severe in intensity. In the real world, patients may hesitate to use a triptan until headache pain is moderate/severe because of the cost of these agents or limited supply allowed by their health service organisation. However, accumulating data indicate that early intervention with an oral triptan when headache pain is still mild may be the most effective acute treatment strategy. Economic analyses also support early triptan intervention in migraine attacks. Tolerability is expected to be particularly important in early intervention, as patients treating mild migraine pain may be more reluctant to risk adverse events. Thus, an agent selected for use as early intervention should have both a demonstrated efficacy in treating mild migraine headache and placebo-like tolerability. This article reviews retrospective and prospective clinical trials which investigated the use of triptans for early acute migraine therapy.

Efficacy of acupuncture for the prophylaxis of migraine: a multicentre randomised controlled clinical trial

BACKGROUND

Our aim was to assess the efficacy of a part-standardised verum acupuncture procedure, in accordance with the rules of traditional Chinese medicine, compared with that of part-standardised sham acupuncture and standard migraine prophylaxis with beta blockers, calcium-channel blockers, or antiepileptic drugs in the reduction of migraine days 26 weeks after the start of treatment.

METHODS

This study was a prospective, randomised, multicentre, double-blind, parallel-group, controlled, clinical trial, undertaken between April 2002 and July 2005. Patients who had two to six migraine attacks per month were randomly assigned verum acupuncture (n=313), sham acupuncture (n=339), or standard therapy (n=308). Patients received ten sessions of acupuncture treatment in 6 weeks or continuous prophylaxis with drugs. Primary outcome was the difference in migraine days between 4 weeks before randomisation and weeks 23-26 after randomisation. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN52683557.

FINDINGS

Of 1295 patients screened, 960 were randomly assigned to a treatment group. Immediately after randomisation, 125 patients (106 from the standard group) withdrew their consent to study participation. 794 patients were analysed in the intention-to-treat popoulation and 443 in the per-protocol population. The primary outcome showed a mean reduction of 2 .3 days (95% CI 1.9-2.7) in the verum acupuncture group, 1.5 days (1.1-2.0) in the sham acupuncture group, and 2.1 days (1.5-2.7) in the standard therapy group. These differences were statistically significant compared with baseline (p<0.0001), but not across the treatment groups (p=0.09). The proportion of responders, defined as patients with a reduction of migraine days by at least 50%, 26 weeks after randomisation, was 47% in the verum group, 39% in the sham acupuncture group, and 40% in the standard group (p=0.133).

INTERPRETATION

Treatment outcomes for migraine do not differ between patients treated with sham acupuncture, verum acupuncture, or standard therapy.

Valdecoxib for treatment of a single, acute, moderate to severe migraine headache

OBJECTIVE

To evaluate the analgesic efficacy and safety of a single 20- or 40-mg dose of valdecoxib compared with placebo in treatment of a single, acute, moderate or severe migraine headache, with or without aura.

BACKGROUND

Valdecoxib, an oral COX-2 specific inhibitor, is indicated for relief of the signs and symptoms of rheumatoid arthritis and osteoarthritis and treatment of primary dysmenorrhea. This study assessed the optimal dose of valdecoxib for treatment of a single, acute, moderate to severe migraine headache.

METHODS

This was a double-blind, randomized, placebo- and active-controlled, multicenter, single-dose (primary end point) and multiple-dose (secondary end point), 56-day study of valdecoxib in the treatment of a single, acute, moderate or severe migraine headache, with or without aura. Migraine headaches were diagnosed according to International Headache Society (IHS) criteria. The primary efficacy end point was headache response (defined as reduction of headache pain intensity from moderate or severe to mild or none) at 2 hours postdose. Patients assessed their headache pain intensity and presence or absence of migraine-associated nausea, vomiting, phonophobia, and photophobia at intervals from 0 to 24 hours postdose. Sumatriptan 50 mg (encapsulated, in standard method, to maintain blinding) was included as a positive control for assay sensitivity. No statistical comparisons were performed between active treatment arms (valdecoxib 20 mg, valdecoxib 40 mg, and sumatriptan 50 mg). Adverse events and safety parameters were monitored throughout the study.

RESULTS

In the intent-to-treat population of 570 patients (135 valdecoxib 20 mg, 151 valdecoxib 40 mg, 143 sumatriptan, and 141 placebo), no significant differences in baseline demographics among treatment groups were observed. The headache response rate with valdecoxib 40 mg and sumatriptan 50 mg was significantly greater than that with placebo at all time points from 2 to 24 hours postdose. With valdecoxib 20 mg, headache response rate was significantly greater than placebo from 2 to 4 hours. Significantly fewer patients treated with valdecoxib 40 mg, compared with placebo, experienced nausea, vomiting, and phonophobia at 2 hours postdose.

CONCLUSIONS

A single 40-mg dose of valdecoxib is effective and well tolerated in treatment of migraine headache pain and associated symptoms.

[The endogenous cannabinoid system. Therapeutic implications for neurologic and psychiatric disorders]

For about 5,000 years, cannabis has been used as a therapeutic agent. There has been growing interest in the medical use of cannabinoids. This is based on the discovery that cannabinoids act with specific receptors (CB1 and CB2). CB1 receptors are located in specific brain areas (e.g. cerebellum, basal ganglia, and hippocampus) and CB2 receptors on cells of the immune system. Endogenous ligands of the cannabinoid receptors were also discovered (e.g. anandamids). Many physiologic processes are modulated by the two subtypes of cannabinoid receptor: motor functions, memory, appetite, and pain. These innovative neurobiologic/pharmacologic findings could possibly lead to the use of synthetic and natural cannabinoids as therapeutic agents in various areas. Until now, cannabinoids were used as antiemetic agents in chemotherapy-induced emesis and in patients with HIV-wasting syndrome. Evidence suggests that cannabinoids may prove useful in some other diseases, e.g. movement disorders such as Gilles de la Tourette's syndrome, multiple sclerosis, and pain. These new findings also explain the acute adverse effects following cannabis use.

Tanacetum parthenium and Salix??alba??(Mig-RL??) Combination in??Migraine Prophylaxis

BACKGROUND

Tanacetum parthenium (feverfew) has been used traditionally to treat migraine, and although its mechanism of action is not fully understood, serotonin 5-HT receptor blocking effects have been suggested. T. parthenium and Salix alba (white willow) either alone or in combination (Mig-RL) were recently shown to inhibit binding to 5-HT(2A/2C) receptors; T. parthenium failed to recognise 5-HT(1D) receptors, whereas S. alba or the combination did. It was hypothesised that S. alba in combination with T. parthenium may provide superior migraine prophylactic activity compared with T. parthenium alone.

METHODS

A prospective, open-label study was performed in 12 patients diagnosed with migraine without aura. Twelve weeks' treatment with T. parthenium 300 mg plus S. alba 300 mg (Mig-RL) twice daily was administered to determine the effects of therapy on migraine attack frequency (primary efficacy criterion), intensity and duration (secondary efficacy criteria), and quality of life, together with tolerability for patients.

RESULTS

Attack frequency was reduced by 57.2% at 6 weeks (p < 0.029) and by 61.7% at 12 weeks (p < 0.025) in nine of ten patients, with 70% patients having a reduction of at least 50%. Attack intensity was reduced by 38.7% at 6 weeks (p < 0.005) and by 62.6% at 12 weeks (p < 0.004) in ten of ten patients, with 70% of patients having a reduction of at least 50%. Attack duration decreased by 67.2% at 6 weeks (p < 0.001) and by 76.2% at 12 weeks (p < 0.001) in ten of ten patients. Two patients were excluded for reasons unrelated to treatment. Self-assessed general health, physical performance, memory and anxiety also improved by the end of the study. Mig-RL treatment was well tolerated and no adverse events occurred.

CONCLUSION

The remarkable efficacy of Mig-RL in not only reducing the frequency of migraine attacks but also their pain intensity and duration in this trial warrants further investigation of this therapy in a double-blind, randomised, placebo-controlled investigation involving a larger patient population.

Eletriptan

Eletriptan (Relpax) is an orally administered, lipophilic, highly selective serotonin 5-HT(1B/1D) receptor agonist ('triptan') that is effective in the acute treatment of moderate to severe migraine attacks in adults. It has a rapid onset of action and demonstrates superiority over placebo as early as 30 minutes after the administration of a single 40 or 80 mg oral dose. The efficacy of eletriptan 20 mg was similar to that of sumatriptan 100 mg, while eletriptan 40 and 80 mg displayed greater efficacy than sumatriptan 50 or 100 mg for most endpoints. Eletriptan 40 mg was generally superior to naratriptan 2.5 mg and equivalent to almotriptan 12.5 mg, rizatriptan 10 mg and zolmitriptan 2.5 mg, while eletriptan 80 mg was superior to zolmitriptan 2.5 mg for most efficacy parameters. Eletriptan 40 and 80 mg were consistently superior to ergotamine/caffeine. Eletriptan is generally well tolerated, reduces time lost from normal activities, improves patients' health-related quality of life and appears to be at least as, if not more, cost effective than sumatriptan. Eletriptan is therefore a useful addition to the triptan family and a first-line treatment option in the acute management of migraine attacks.

Efficacy and safety of 6.25 mg t.i.d. feverfew CO2-extract (MIG-99) in migraine prevention--a randomized, double-blind, multicentre, placebo-controlled study

The efficacy and tolerability of a CO(2)-extract of feverfew (MIG-99, 6.25 mg t.i.d.) for migraine prevention were investigated in a randomized, double-blind, placebo-controlled, multicentre, parallel-group study. Patients (N = 170 intention-to-treat; MIG-99, N = 89; placebo, N = 81) suffering from migraine according to International Headache Society criteria were treated for 16 weeks after a 4-week baseline period. The primary endpoint was the average number of migraine attacks per 28 days during the treatment months 2 and 3 compared with baseline. Safety parameters included adverse events, laboratory parameters, vital signs and physical examination. The migraine frequency decreased from 4.76 by 1.9 attacks per month in the MIG-99 group and by 1.3 attacks in the placebo group (P = 0.0456). Logistic regression of responder rates showed an odds ratio of 3.4 in favour of MIG-99 (P = 0.0049). Adverse events possibly related to study medication were 9/107 (8.4%) with MIG-99 and 11/108 (10.2%) with placebo (P = 0.654). MIG-99 is effective and shows a favourable benefit-risk ratio.

Focus on trial endpoints of clinical relevance and the use of almotriptan for the acute treatment of migraine

Almotriptan is a 5-HT(1B/1D) receptor agonist, or triptan, indicated for the acute treatment of migraine. It has been shown to be effective and well tolerated for the treatment of acute migraine in approximately 5000 patients enrolled in short-term placebo- and active-controlled trials and long-term open-label trials. A recent meta-analysis reported that almotriptan has the highest sustained pain-free (SPF) rate and lowest adverse-event (AE) rate of all oral triptans. Sustained pain free is a composite endpoint of pain freedom at 2 h, no recurrence of moderate-to-severe headache and no use of rescue medication from 2 to 24 h after dosing. Patient surveys have indicated that migraine sufferers consider complete pain relief, no recurrence, rapid onset and no side-effects to be the most important attributes of their acute treatment. Composite endpoints such as SPF and SPF with no AEs (SNAE) contain the attributes that migraine sufferers express as being the most important elements of an acute migraine therapy, and their use in future clinical trials should aid in the selection of agents that can offer patients the highest likelihood of consistent treatment success.

Efficacy of almotriptan 12.5 mg in achieving migraine-related composite endpoints: a double-blind, randomized, placebo-controlled study in patients controlled study in patients with previous poor response to sumatriptan 50 mg

BACKGROUND

Triptans are not identical and migraine sufferers respond differently to different triptans. Few studies have evaluated the efficacy of switching triptans in migraine patients who have shown poor response to another agent.

OBJECTIVE

To investigate the efficacy and tolerability of almotriptan 12.5 mg in patients who did not achieve 2-h pain relief with sumatriptan 50 mg.

METHODS

This double-blind, placebo-controlled study recruited patients with IHS-defined migraine and at least 2 previous unsatisfactory responses to sumatriptan. Those who did not achieve pain relief (moderate or severe pain decreasing to mild or no pain) 2 h after taking oral sumatriptan 50 mg on an open-label basis for the treatment of their first migraine attack during this trial (Attack 1) were randomized to receive either oral almotriptan 12.5 mg or placebo for the treatment of their next migraine attack (Attack 2).

RESULTS

Of 302 patients receiving sumatriptan 50 mg for the treatment of their first migraine attack, 221 (73%) did not achieve 2-h pain relief and were randomized to almotriptan 12.5 mg or placebo for the treatment of Attack 2. The majority (70%) of randomized patients treating their headache in Attack 2 reported severe pain at baseline characterizing this as a difficult-to-treat population. In the intent-to-treat population (n = 198), significantly more patients in the almotriptan group compared with the placebo group achieved 2-h complete relief (free from pain and migraine-associated symptoms) at 2 h (17.1% vs. 4.4%; p < 0.05) and sustained pain free (20.9% vs. 9.0%; p < 0.05). Adverse events of mild-to-moderate intensity occurred in 7.1% of patients in the almotriptan group compared to 5.1% in the placebo group (not statistically different).

CONCLUSION

Almotriptan is more effective than placebo and similarly well-tolerated for the acute treatment of migraine in patients who responded poorly to oral sumatriptan.

Sinus headache: a neurology, otolaryngology, allergy, and primary care consensus on diagnosis and treatment

Sinus headache is a widely accepted clinical diagnosis, although many medical specialists consider it an uncommon cause of recurrent headaches. The inappropriate diagnosis of sinus headache can lead to unnecessary diagnostic studies, surgical interventions, and medical treatments. Both the International Headache Society and the American Academy of Otolaryngology-Head and Neck Surgery have attempted to define conditions that lead to headaches of rhinogenic origin but have done so from different perspectives and in isolation of each other. An interdisciplinary ad hoc committee convened to discuss the role of sinus disease as a cause of headache and to review recent epidemiological studies that suggest sinus headache (headache of rhinogenic origin) and migraine are frequently confused with one another. This committee reviewed available scientific evidence from multiple disciplines and concluded that considerable research and clinical study are required to further understand and delineate the role of nasal pathology and autonomic activation in migraine and headaches of rhinogenic origin. However, this group agreed that greater diagnostic and therapeutic attention needs to be given to patients with sinus headaches.

Almotriptan in Migraine Patients Who Respond Poorly to Oral Sumatriptan: A Double-Blind, Randomized Trial

OBJECTIVE

To investigate the efficacy and tolerability of almotriptan 12.5 mg in migraine patients who respond poorly to sumatriptan 50 mg.

BACKGROUND

Poor response to sumatriptan therapy for acute migraine attacks has been documented in the literature, but few controlled trials have investigated the efficacy of an alternative triptan in this subgroup of patients.

METHODS

Patients with an International Headache Society diagnosis of migraine who self-described as experiencing at least two unsatisfactory responses to sumatriptan treated their first migraine attack with open-label sumatriptan 50 mg. Patients who did not achieve 2-hour pain relief (improvement of headache from moderate/severe to mild/no headache) were then randomized to treat their second attack with almotriptan 12.5 mg or placebo under double-blind conditions.

RESULTS

In the first attack, 221 of 302 participants (73%) did not achieve 2-hour pain relief with sumatriptan and were randomized to treatment of their second attack with almotriptan 12.5 mg or placebo. Of the 198 sumatriptan nonresponders who treated their second attack (99 almotriptan; 99 placebo), 70% had severe headache pain at baseline. Two-hour pain-relief rates were significantly higher with almotriptan compared to placebo (47.5% vs 23.2%; P<.001). A significant treatment effect for almotriptan was also seen in pain-free rates at 2 hours (33.3% vs 14.1%; P<.005) and sustained freedom from pain (20.9% vs 9.0%; P<.05). In the second attack, 7.1% of patients in the almotriptan group experienced adverse events compared to 5.1% in the placebo group (P=.77).

CONCLUSIONS

Almotriptan 12.5 mg is an effective and well-tolerated alternative for patients who respond poorly to sumatriptan 50 mg. A poor response to one triptan does not predict a poor response to other agents in that class.

Almotriptan in migraine patients who respond poorly to oral sumatriptan: a double-blind, randomized trial

OBJECTIVE

To investigate the efficacy and tolerability of almotriptan 12.5 mg in migraine patients who respond poorly to sumatriptan 50 mg.

BACKGROUND

Poor response to sumatriptan therapy for acute migraine attacks has been documented in the literature, but few controlled trials have investigated the efficacy of an alternative triptan in this subgroup of patients.

METHODS

Patients with an International Headache Society diagnosis of migraine who self-described as experiencing at least two unsatisfactory responses to sumatriptan treated their first migraine attack with open-label sumatriptan 50 mg. Patients who did not achieve 2-hour pain relief (improvement of headache from moderate/severe to mild/no headache) were then randomized to treat their second attack with almotriptan 12.5 mg or placebo under double-blind conditions.

RESULTS

In the first attack, 221 of 302 participants (73%) did not achieve 2-hour pain relief with sumatriptan and were randomized to treatment of their second attack with almotriptan 12.5 mg or placebo. Of the 198 sumatriptan nonresponders who treated their second attack (99 almotriptan; 99 placebo), 70% had severe headache pain at baseline. Two-hour pain-relief rates were significantly higher with almotriptan compared to placebo (47.5 vs. 23.2%; p < 0.001). A significant treatment effect for almotriptan was also seen in pain-free rates at 2 h (33.3 vs. 14.1%; p < 0.005) and sustained freedom from pain (20.9 vs. 9.0%; p < 0.05). In the second attack, 7.1% of patients in the almotriptan group experienced adverse events compared to 5.1% in the placebo group (p = 0.77).

CONCLUSIONS

Almotriptan 12.5 mg is an effective and well-tolerated alternative for patients who respond poorly to sumatriptan 50 mg. A poor response to one triptan does not predict a poor response to other agents in that class.

Triptan Nonresponder Studies: Implications for Clinical Practice

The maximum absolute response rate with oral triptans, as measured in clinical trials by the incidence of relief from migraine pain at 2 hours after taking medication, is approximately 70%. Therefore around 30% of patients fail to respond to a particular triptan. Nonresponse is likely to be due to a variety of factors, including low and inconsistent absorption, use of the medication late in an attack, inadequate dosing, and variability in individual response. Evidence from recent clinical trials, however, confirms the common clinical observation that patients with a poor response to one triptan can benefit from subsequent treatment with a different triptan. Two-hour pain-relief rates of 25% to 81% using alternative triptans (naratriptan, almotriptan, eletriptan, zolmitriptan, and rizatriptan) have been reported in patients who were described as poor responders to sumatriptan. Physicians should remain vigilant in assessing the response to acute therapy and take advantage of simple clinical questionnaires that have been developed to facilitate the recognition of those patients who require and may benefit from a change in acute therapy.

Adverse reactions related to drugs for headache treatment: clinical impact

OBJECTIVE

To assess the clinical impact of adverse reactions related to drugs for primary headache treatment.

METHODS

We examined the adverse reactions to 360 medications prescribed by the specialists of the Headache Centre of the University of Modena and Reggio Emilia to 256 consecutive outpatients (214 female, 42 male; mean age: 38.88 +/- 14.06 years; range 10-72 years). Adverse reactions were reported by patients during scheduled follow-up visits, classified by specialists and reassessed by a clinical pharmacologist.

RESULTS

Adverse reactions with a causal relationship classified as definite/probable/possible were 202 (56%): 62% (80/129) were due to acute treatments and 53% (122/231) to prophylactic treatments (chi2 test, P = 0.115 ns). More than 90% of the adverse reactions were of limited intensity [mild (58%) or moderate (36%)]. Only 5% were severe, and two reactions (1%) were serious. The most affected apparatus was the nervous system (41%). Of these adverse reactions, 43% caused the discontinuance of the treatment, especially of prophylaxis (54%). Patients evaluated 70% of the medications as effective, but, at the same time, they considered most of the adverse reactions (69%) unacceptable.

CONCLUSION

Adverse reactions related to headache medications have a strong impact on patients' management, even if their real intensity and severity are usually very limited. Drugs for headache treatment are still far from being ideal drugs. To prevent the discontinuance of effective medications, the physician, prior to prescribing, should assess, together with the patient, the acceptability of the more common adverse drug reactions.

3-(2-Pyrrolidin-1-ylethyl)-5-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole derivatives as high affinity human 5-HT1B/1D ligands

A series of 3-(2-pyrrolidin-1-ylethyl)-5-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole derivatives (2) has been prepared using parallel synthesis techniques, and their structure-activity relationships studied. High affinity human 5-HT(1B/1D) (h5-HT(1B/1D)) ligands have been identified.

( R )-3-( N -Methylpyrrolidin-2-ylmethyl)-5-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole derivatives as high affinity h5-HT 1B/1D ligands

A series of (R)-3-(N-methylpyrrolidin-2-ylmethyl)-5-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole derivatives (2) have been prepared using parallel synthesis, and their structure-activity relationship studied. High affinity human 5-HT(1B/1D) (h5-HT(1B/1D)) ligands have been identified.

Dihydroergotamine and its metabolite, 8'-hydroxy-dihydroergotamine, as 5-HT1A receptor agonists in the rat brain

1 In addition to stopping migraine attacks, dihydroergotamine (DHE) is an efficient drug for migraine prophylaxis. Whether 5-HT(1A) receptors could contribute to the latter action was assessed by investigating the effects of DHE and its metabolite, 8'-OH-DHE, on these receptors in the rat brain. 2 Membrane binding assays with [(3)H]8-OH-DPAT and [(3)H]WAY 100635 as radioligands showed that both DHE (IC(50)=28-30 nM) and 8'-OH-DHE (IC(50)=8-11 nM) are high-affinity 5-HT(1A) receptor ligands. 3 Both DHE and 8'-OH-DHE enhanced the specific binding of [(35)S]GTP-gamma-S to the dorsal raphe nucleus and the hippocampus in brain sections, but to a lower extent than 5-carboxamido-tryptamine (5-CT) in the latter area. 4 Both DHE (EC(50)=10.9+/-0.3 nM) and 8'-OH-DHE (EC(50)=30.4+/-0.8 nM) inhibited the firing of serotoninergic neurons in the dorsal raphe nucleus within brain stem slices. 5 Intracellular recording showed that 8'-OH-DHE was more potent than DHE to hyperpolarize CA1 pyramidal cells in rat hippocampal slices. 6 Both the stimulatory effects of DHE and 8'-OH-DHE on [(35)S]GTP-gamma-S binding and their electrophysiological effects were completely prevented by the selective 5-HT(1A) receptor antagonist WAY 100635. 7 As expected of 5-HT(1A) receptor partial agonists, DHE and 8'-OH-DHE prevented any subsequent hyperpolarization of CA1 pyramidal cells by 5-HT or 5-CT. 8 Through their actions at 5-HT(1A) auto- (in the dorsal raphe nucleus) and hetero-(notably in the hippocampus) receptors, DHE, and even more its metabolite 8'-OH-DHE, can exert both an inhibitory influence on neuronal excitability and anxiolytic effects which might contribute to their antimigraine prophylactic efficiency.

Metallic taste: an unusual reaction to botulinum toxin A

BACKGROUND

Botulinum neurotoxin formulations are safe and effective agents for the treatment of facial rhytides.

OBJECTIVES

A patient is described who complained of metallic taste after each treatment with botulinum toxin A (BTX-A).

RESULTS

The sensation of metallic taste diminished after successive treatments with BTX-A, despite adequate dosing for cosmetic purposes.

CONCLUSION

Metallic taste is associated with the use of numerous medications; however, the pathogenesis remains unclear. Alteration in zinc metabolism, which may occur with BTX-A administration, has been suggested as a possible mechanism. Although this is the first known report of dysgeusia after BTX-A, physicians and patients may be reassured that the taste alteration was self-limited and was not significantly problematic for the patient in our case.

Pharmacological treatment of vertigo

This review discusses the physiology and pharmacological treatment of vertigo and related disorders. Classes of medications useful in the treatment of vertigo include anticholinergics, antihistamines, benzodiazepines, calcium channel antagonists and dopamine receptor antagonists. These medications often have multiple actions. They may modify the intensity of symptoms (e.g. vestibular suppressants) or they may affect the underlying disease process (e.g. calcium channel antagonists in the case of vestibular migraine). Most of these agents, particularly those that are sedating, also have a potential to modulate the rate of compensation for vestibular damage. This consideration has become more relevant in recent years, as vestibular rehabilitation physical therapy is now often recommended in an attempt to promote compensation. Accordingly, therapy of vertigo is optimised when the prescriber has detailed knowledge of the pharmacology of medications being administered as well as the precise actions being sought. There are four broad causes of vertigo, for which specific regimens of drug therapy can be tailored. Otological vertigo includes disorders of the inner ear such as Ménière's disease, vestibular neuritis, benign paroxysmal positional vertigo (BPPV) and bilateral vestibular paresis. In both Ménière's disease and vestibular neuritis, vestibular suppressants such as anticholinergics and benzodiazepines are used. In Ménière's disease, salt restriction and diuretics are used in an attempt to prevent flare-ups. In vestibular neuritis, only brief use of vestibular suppressants is now recommended. Drug treatments are not presently recommended for BPPV and bilateral vestibular paresis, but physical therapy treatment can be very useful in both. Central vertigo includes entities such as vertigo associated with migraine and certain strokes. Prophylactic agents (L-channel calcium channel antagonists, tricyclic antidepressants, beta-blockers) are the mainstay of treatment for migraine-associated vertigo. In individuals with stroke or other structural lesions of the brainstem or cerebellum, an eclectic approach incorporating trials of vestibular suppressants and physical therapy is recommended. Psychogenic vertigo occurs in association with disorders such as panic disorder, anxiety disorder and agoraphobia. Benzodiazepines are the most useful agents here. Undetermined and ill-defined causes of vertigo make up a large remainder of diagnoses. An empirical approach to these patients incorporating trials of medications of general utility, such as benzodiazepines, as well as trials of medication withdrawal when appropriate, physical therapy and psychiatric consultation is suggested.

Integrating the triptans into clinical practice

The triptans (selective serotonin agonists) are becoming the first-line alternatives in the acute pharmacological treatment of migraine, at least for attacks of moderate-to-severe intensity. Although clinical trials demonstrate significant differences in efficacy between triptan tablets, they often appear similar in efficacy when used in clinical practice, particularly after dose adjustments. Most patients with migraine consider drugs that can be administered orally to be the most user-friendly. However, gastrointestinal absorption may be impaired during migraine attacks because gastric motility is inhibited, and there is a risk that nausea during the attack will culminate in vomiting. Furthermore, in addition to their antimigraine properties, triptans may prolong the gastric emptying time. For this reason the absorption of any triptan taken orally during the migraine attack will be erratic and treatment effects inconsistent. Despite these barriers to good efficacy and high reliability, the tablet is the most commonly used triptan formulation.