Pharmacology and efficacy of eletriptan for the treatment of migraine attacks

Sumatriptan, a 5-HT 1B/1D agonist, was introduced 10 years ago and was the most effective therapy for migraine attacks at that time. Eletriptan is a new 5-HT 1B/1D agonist with high potency and selectivity at 5-HT 1B/1D receptors. It is effective in animal models in which the vascular and neurogenic mechanisms implicated in migraine were measured. Eletriptan is selective for the intracranial blood vessels over other extracranial vasculature, in particular coronary arteries. Eletriptan has a rapid and complete oral absorption and a good oral bioavailability in migraineurs. In comparative trials 20 mg, 40 mg and 80 mg eletriptan, 100 mg sumatritpan and placebo were compared for the treatment of migraine attacks. All three doses of eletriptan were statistically superior to placebo for headache response and headache-free patients. The 80 mg dose of eletriptan was also superior to sumatriptan 100 mg. Headache recurrence, defined as return of moderate or severe headache within 24 hours of dosing and following a headache response at two hours after initial dosing, occurred in 33% of the patients following 100 mg sumatriptan and in 28%, 34% and 32% after 20 mg, 40 mg and 80 mg eletriptan. In another large trial, headache response rates were significantly higher for both doses of eletriptan (64% for 40 mg and 67% for 80 mg) than for two doses of sumatriptan (50% for 50 mg and 53% for 100 mg). Eletriptan 40 mg or 80 mg was also superior to ergotamine plus caffeine (Cafergot). In summary, eletriptan is a highly effective and fast-acting drug for the treatment of acute migraine attacks.

Lubeluzole in acute ischemic stroke treatment: A double-blind study with an 8-hour inclusion window comparing a 10-mg daily dose of lubeluzole with placebo

BACKGROUND AND PURPOSE

This trial was a double-blind, placebo-controlled, phase III trial with an 8-hour inclusion window to assess the efficacy and safety of an intravenous loading dose of 7.5 mg followed by a daily intravenous dose of 10 mg lubeluzole for 5 days in acute ischemic stroke patients.

METHODS

A total of 1786 patients were randomized: 901 to lubeluzole and 885 to placebo. Overall, 212 patients (23.5%) from the lubeluzole group and 213 (24.1%) from the placebo group discontinued the trial prematurely. In the lubeluzole group 201 patients (22.3%) discontinued because of adverse events compared with 193 patients (21.8%) in the placebo group.

RESULTS

The primary population for the efficacy analysis comprised the core stroke patients (exclusion of older patients aged >75 years with severe stroke) in the 0- to 6-hour inclusion time window. The primary efficacy parameter was a 3-category functional status (Barthel Index 70 to 100/0 to 70/vegetative, dead) at week 12. In the lubeluzole group 207 patients (47.8%) were classified as mildly dependent/independent at week 12, 131 (30.3%) were moderately/severely dependent, and 95 (21.9%) were vegetative/dead. In the placebo group these numbers were 221 (54.4%), 112 (27.6%), and 73 (18.0%), respectively. Logistic regression analysis showed no statistically significant difference between the treatment groups (P:=0.162). Additionally, for none of the secondary efficacy parameters (mortality at week 12, modified Rankin score, total Barthel score) was a statistically significant difference between the lubeluzole and placebo groups obtained. There were no statistically significant differences between the 2 treatments for all treated patients, patients included within the 6- to 8-hour window, and patients with severe strokes aged >75 years. Overall, of all treated patients, 401 (22.5%) died: 203 (22.5%) in the lubeluzole group and 198 (22.4%) with placebo. Of all subjects treated, 853 (95%) on lubeluzole and 826 (93%) on placebo reported an adverse event during their treatment period or within the next 2 days after discontinuation of treatment. The most frequently observed adverse events were fever (25.9% lubeluzole; 23.4% placebo), constipation (20.2%; 19.7%), and headache (17.6%; 21.2%). Imbalances were found for atrial fibrillation (1.8% lubeluzole; 1.1% placebo) and QT prolongation (0.9%; 0.2%).

CONCLUSIONS

This study failed to show an efficacy of lubeluzole in the treatment of acute stroke. On the other hand, lubeluzole treatment by the current dosage schedule was not associated with a significant safety problem.

Efficacy of naratriptan tablets in the acute treatment of migraine: a dose-ranging study. Naratriptan S2WB2004 Study Group

OBJECTIVE

This study sought to compare the efficacy of several doses of naratriptan tablets with that of sumatriptan tablets and placebo in the acute treatment of a single migraine attack.

METHODS

This was a randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study. Patients received either naratriptan tablets (1, 2.5, 5, 7.5, or 10 mg), sumatriptan tablets (100 mg), or placebo.

RESULTS

A total of 643 patients took part in the study. Two hours after dosing, headache relief was reported by significantly more patients treated with any dose of naratriptan (52%-69%) or sumatriptan (60%) than with placebo (31%) (P < 0.05). Four hours after dosing, headache relief was reported by significantly more patients treated with any dose of naratriptan (63%-80%) or sumatriptan (80%) than with placebo (39%) and by significantly more patients treated with sumatriptan 100 mg (80%) than with naratriptan 1 mg (64%), 2.5 mg (63%), or 5 mg (65%) (P < 0.05). Twenty-four-hour overall efficacy (headache relief maintained through 24 hours postdose with no worsening, no use of rescue medication, and no recurrence) was reported by more patients treated with any dose of naratriptan (39%-58%) or sumatriptan (44%) than with placebo (22%). Headache recurrence was reported in 17% to 32% of naratriptan-treated patients, 44% of sumatriptan-treated patients, and 36% of placebo recipients. The overall incidence of adverse events was similar in patients treated with naratriptan 1 mg (20%), naratriptan 2.5 mg (21%), and placebo (23%). For naratriptan 5, 7.5, and 10 mg, the incidence of adverse events was 32%, 37%, and 35%, respectively, and for sumatriptan 100 mg it was 26%.

CONCLUSIONS

Our results suggest that the 2.5-mg dose of naratriptan tablets offers the optimal efficacy-to-tolerability ratio at the dose range between 1 and 10 mg. Although naratriptan 2.5 mg was less effective than sumatriptan 100 mg at 4 hours after dosing, the 2 medications showed similar efficacy at 24 hours.

Involvement of the human medial cerebellum in long-term habituation of the acoustic startle response

Animal studies have shown an involvement of the cerebellar vermis in long-term habituation of the acoustic startle response, but not in short-term habituation. The aim of the present study was to investigate whether short-term and long-term habituation of the acoustic startle response are impaired in patients with medial cerebellar lesions. Five patients with midline cerebellar lesions due to surgery for astrocytoma and ten healthy, age- and sex-matched subjects were studied. Subjects received 40 acoustic startle stimuli each day on five successive days. Peak amplitudes of the startle response recorded at the orbicularis oculi and the sternomastoid muscles were obtained. Data were analyzed for response decrement within the training session of one day (short-term habituation) and for a decrease in the startle response across the five training days (long-term habituation). Short- and long-term habituation of the startle response recorded at the sternomastoid muscles could be achieved in controls and in cerebellar patients. However, long-term habituation of the blink component of the acoustic startle response recorded at the orbicularis oculi muscles was significantly impaired in patients with cerebellar lesions compared with control subjects, whereas short-term habituation was preserved in both groups. The present findings suggest that the medial cerebellum is involved in long-term habituation of the blink component of the startle response in humans.

[Psychological descriptors of excessive use of analgesic medication]

INTRODUCTION

Patients suffering from migraine and tension-type-headache are at risk of misusing analgesics and therefore developing chronic drug-induced headache. The present study compares migraine patients with and without abuse to identify psychological descriptors promoting drug abuse.

METHODS

We examined 21 in-patients with migraine and drug-abuse and 21 out-patients with migraine and no drug-abuse who were comparable regarding age and diverse pain variables (intensity, frequency, duration, etc. ). Psychometric questionnaires measured the constructs "pain-", "depression", "self-efficacy" and "pain-coping". Using a standardized interview we investigated the external (environment) and internal (mental factors) conditions of all patients during medication intake.

RESULTS

Migraineurs who misused medications showed significantly greater disability, greater helplessness and anxiety due to pain and a tendency towards more marked general depression than non-abusers. The extent of the helpless and depressive coping with pain was best suited for distinguishing the patients with and without drug abuse, followed by the fact that those with abuse receive drugs from several doctors at the same time and demand that the drugs free them of all complaints.

CONCLUSIONS

These findings suggest that migraine patients with drug abuse often take analgesics not according to their headache, but rather depending on certain other factors.

Aura in some patients with familial hemiplegic migraine can be stopped by intranasal ketamine

Migraine aura is probably caused by cortical-spreading depression. No treatment for acute and severe migraine aura has been described previously. The effect of ketamine (25 mg intranasally) was studied in 11 patients with severe, disabling auras resulting from familial hemiplegic migraine. In five patients ketamine reproducibly reduced the severity and duration of the neurologic deficits, whereas in the remaining six patients no beneficial effect was seen. Ketamine offers, for the first time, a possible treatment option for severe and prolonged aura.

Glycine antagonist (gavestinel) in neuroprotection (GAIN International) in patients with acute stroke: a randomised controlled trial. GAIN International Investigators

BACKGROUND

Early treatment may improve acute ischaemic stroke outcome. Gavestinel is a selective antagonist at the glycine site of the N-methyl-D-aspartate (NMDA) receptor, and is neuroprotective in animal models of ischaemic stroke.

METHODS

We did a randomised, double-blind, placebo-controlled trial to test whether gavestinel could improve functional outcome after acute stroke in human beings. Conscious patients with stroke involving limb weakness received either gavestinel at an intravenous loading dose of 800 mg followed by 200 mg every 12 h for five doses, or matching placebo, within 6 h of stroke onset. Stratification variables were age and stroke severity. A computed tomography brain scan within 18 h of stroke onset identified the primary efficacy population with ischaemic stroke. Outcome was assessed by an independent observer with the Barthel index at 3 months. Three outcome categories were applied: good (Barthel index 95-100), moderate (60-90), and poor (0-55 or dead). Analysis was by intention to treat.

FINDINGS

Of 1804 patients randomised, 16 received no treatment, and 333 had primary intracranial haemorrhage. 891 patients received gavestinel and 897 received placebo. Outcome in 721 patients who received gavestinel and were analysed for the primary endpoint at 3 months was good in 246 (34.1%), moderate in 136 (18.8%), and poor in 339 (47.0%), compared with 256 (34.9%), 133 (18.1%), and 345 (47.0%), respectively, of 734 patients who received placebo (p=0.8). Mortality at 3 months was 147 (20.4%) in the gavestinel group and 138 (18.8%) in the placebo group. Outcomes within preplanned subgroup and secondary analyses were also neutral. There were no significant differences in serious side-effects between the groups.

INTERPRETATION

Treatment with gavestinel within 6 h of acute ischaemic stroke did not improve outcome.

Design of the blockade of the glycoprotein IIb/IIIa receptor to avoid vascular occlusion (BRAVO) trial

BACKGROUND

Platelets play a key role in the pathogenesis of atherosclerosis, thrombosis, and acute coronary and cerebrovascular syndromes. Inhibition of platelet function by acetylsalicylic acid (aspirin) has been shown to reduce the incidence atherothrombotic events in patients with coronary, cerebrovascular, or peripheral vascular disease. Thienopyridine agents, however, including ticlopidine and clopidogrel, inhibit the adenosine diphosphate receptor and have modestly superior effects compared with aspirin on reduction of death, myocardial infarction, and stroke among a broad group of patients with vascular disease. More effective antithrombotic agents are still required to treat patients at high risk for recurrent vascular events.

METHODS

Lotrafiban, a selective, nonpeptide antagonist of the human platelet fibrinogen receptor (glycoprotein [GP] IIb/IIIa [alphaIIb/beta3 integrin]), blocks the binding of fibrinogen to the GP IIb/IIIa receptor, which is the final common pathway of platelet aggregation. Lotrafiban at doses of up to 50 mg twice daily was well-tolerated in a 12-week, double-blind, placebo-controlled, dose-ranging study in patients with recent myocardial infarction, unstable angina, transient ischemic attack, or stroke when added to aspirin therapy. On the basis of these results, a dosing regimen was selected for the phase III Blockage of the Glycoprotein IIb/IIIa Receptor to Avoid Vascular Occlusion (BRAVO) trial based on pharmacodynamics and drug tolerability. In the pivotal BRAVO study, lotrafiban therapy is being evaluated in patients who have had a recent myocardial infarction, unstable angina, transient ischemic attack, or ischemic stroke, or who present at any time after a diagnosis of peripheral vascular disease combined with either cardiovascular or cerebrovascular disease.

RESULTS

The efficacy evaluation will be based on a composite end point of clinical events (death by any cause, myocardial infarction, stroke, recurrent ischemia requiring hospitalization, or urgent ischemia-driven revascularization). The target enrollment is 9200 patients worldwide. Approximately 700 centers will participate and will be distributed within 30 countries across North America, Europe, Australia, and Asia.

Comparison of rizatriptan 10 mg vs. zolmitriptan 2.5 mg in the acute treatment of migraine. Rizatriptan-Zolmitriptan Study Group

The efficacy and tolerability of rizatriptan (MAXALT) and zolmitriptan (ZOMIG) were compared in a randomized, double-blind, double-dummy, stratified (on prior use of rizatriptan and/or zolmitriptan), placebo-controlled, single attack study in 766 patients. Rizatriptan tended to provide freedom from pain sooner than zolmitriptan (hazard ratio 1.26, P = 0.075), acting within 60 min following dosing. More patients were pain free at 2 h on rizatriptan than on zolmitriptan (43.2% vs. 35.6%, P=0.041), while headache relief at 2 h was similar (70.5% vs. 66.8%). At 2 h, fewer patients on rizatriptan had symptoms of photophobia (35.6% vs. 43.5%, P = 0.029) and nausea (25.2% vs. 32.5%, P=0.046), and more patients on rizatriptan had normal function (45.4% vs. 37.0%, P=0.025) than zolmitriptan. Headache recurred in 28% of patients taking rizatriptan, 29% taking zolmitriptan and 26% taking placebo. Both active treatments were effective compared to placebo and were well tolerated. The most common side-effects with rizatriptan were asthenia/fatigue, somnolence and dizziness, while the most common side-effects with zolmitriptan were asthenia/fatigue and dizziness.

A possible role of the human cerebellum in conditioning of the jaw-opening reflex

The role of the human cerebellum in classical conditioning of the jaw-opening reflex was investigated using positron emission tomography (PET) in healthy subjects. The jaw-opening reflex was elicited by electrical stimulation of the right corner of the mouth (unconditioned stimulus, US). The conditioned stimulus was a tone preceding the US and coterminating with the US. Changes of regional cerebral blood flow (rCBF) were correlated with the rate of conditioning per PET scan. Conditioning effects were present in one third of all subjects. In these subjects, a significant increase of rCBF in the ipsilateral, intermediate cerebellum was shown during ongoing conditioning. Thus, the intermediate cerebellum appears to be involved in classical conditioning of the jaw-opening reflex in humans.

Stroke prevention: anti-platelet and anti-thrombolytic therapy

In patients with TIA or ischemic stroke of noncardiac origin antiplatelet drugs are able to decrease the risk of stroke by 11-15%, and the risk of stroke, MI, and vascular death by 15-22%, but not mortality. Low doses of aspirin (50-325 mg) are as effective as high doses and cause less gastrointestinal side effects. Severe bleeding complications are not dose-dependent. The combination of aspirin with slow release dipyridamole is superior to aspirin alone for stroke prevention. Ticlopidine is superior to aspirin but has slightly more serious adverse effects (neutropenia). It will be replaced by clopidgrel which has a better safety profile. Anticoagulation with an INR between 3.0 and 4.5 is too dangerous. Whether anticoagulation with lower INR is safe and effective is not yet known.

Fear conditioned potentiation of the acoustic blink reflex in patients with cerebellar lesions

OBJECTIVE

To investigate whether the human cerebellum takes part in fear conditioned potentiation of the acoustic blink reflex.

METHODS

A group of 10 cerebellar patients (eight patients with lesions involving the medial cerebellum, two patients with circumscribed lesions of the cerebellar hemispheres) was compared with a group of 16 age and sex matched healthy control subjects. The fear conditioned potentiation paradigm consisted of three phases. During the first, habituation phase subjects received 20 successive acoustic blink stimuli. In the subsequent fear conditioning phase, subjects passed through 20 paired presentations of the unconditioned fear stimulus (US; an electric shock) and the conditioned stimulus (CS; a light). Thereafter, subjects underwent the potentiation phase, which consisted of a pseudorandom order of 12 trials of the acoustic blink stimulus alone, 12 acoustic blink stimuli paired with the conditioned stimulus, and six conditioned stimuli paired with the unconditioned stimulus. The EMG of the acoustic blink reflex was recorded at the orbicularis oculi muscles. The potentiation effect was determined as the difference in normalised peak amplitude of the blink reflex evoked by pairs of CS and acoustic blink stimuli and evoked by the acoustic stimulus alone.

RESULTS

In the habituation phase, short term habituation of the acoustic blink reflex was preserved in all cerebellar patients. However, in the potentiation phase, the potentiation effect of the blink reflex was significantly reduced in patients with medial cerebellar lesions compared with the controls (mean (SD) potentiation effect (%), patients: -6.4 (15.3), controls: 21.6 (35.6)), but was within normal limits in the two patients with lateral lesions.

CONCLUSIONS

The present findings suggest that the human medial cerebellum is involved in associative learning of non-specific aversive reactions-that is, the fear conditioned potentiation of the acoustic blink reflex.

Focal myopathy induced by chronic heroin injection is reversible

We report a patient who developed a focal myopathy with prominent contractures of his thigh muscles induced by chronic heroin injection. Muscle biopsy and magnetic resonance imaging (MRI) were indicative of a fibrotic and inflammatory process. Treatment with steroids, D-penicillamine, and physical therapy led to full functional recovery within 6 months. Sequential electromyographic (EMG) studies and muscle biopsies showed evidence of regenerating muscle fibers and absence of inflammatory cells. We conclude that heroin-induced focal myopathy is reversible and that combination therapy with D-penicillamine and steroids may be useful.

Classically conditioned withdrawal reflex in cerebellar patients. 1. Impaired conditioned responses

The role of the cerebellum in the classically conditioned, human lower-limb-withdrawal reflex was studied in ten patients with pure cerebellar diseases (CBL), ten patients showing additional extracerebellar symptoms (CBL+), and in 11 sex- and age-matched normal controls (CTRL). Where conditioning was successful, the electrically evoked, unconditioned response was preceded by a tone-conditioned response (CR). CR incidence was variable, with best results in the CTRL, significantly less in CBL, and lowest in CBL+. Although CRs could be established in subjects in all groups, a continuous increase in the CR incidence in the course of the recording session was observed primarily in CTRL. In CBL and CBL+, such a characteristic reflex acquisition was rather the exception. CR onsets in CBL were within the range of those in CTRL, but CR amplitude was significantly lower in CBL. Cerebellar patients with circumscribed lesions behaved differently in our motor-learning paradigm, depending on the lesion site. Patients suffering from pathology of the posterior inferior cerebellum showed a mean CR incidence within the lower range of CTRL. In contrast, if the anterior and superior cerebellum was affected, few or even no CRs were observed. Our findings thus provide evidence that the human cerebellum is required for the acquisition and the retention of this specific conditioned limb-withdrawal reflex. In particular, anterior and superior parts of the cerebellum appear to be involved. Thus, an expansion of the current concept of clinically based, functional compartmentalization is suggested, such that anterior and superior cerebellar regions must be intact to establish plastic changes required for the acquisition of the conditioned withdrawal response.

Selfotel in acute ischemic stroke : possible neurotoxic effects of an NMDA antagonist

BACKGROUND AND PURPOSE

Based on neuroprotective efficacy in animal models, we evaluated the N-methyl D-aspartate antagonist Selfotel in patients with ischemic stroke, after doses up to 1.5 mg/kg were shown to be safe in phase 1 and phase 2a studies.

METHODS

Two pivotal phase 3 ischemic stroke trials tested the hypothesis, by double-blind, randomized, placebo-controlled parallel design, that a single intravenous 1.5 mg/kg dose of Selfotel, administered within 6 hours of stroke onset, would improve functional outcome at 90 days, defined as the proportion of patients achieving a Barthel Index score of >/=60. The trials were performed in patients aged 40 to 85 years with acute ischemic hemispheric stroke and a motor deficit.

RESULTS

The 2 trials were suspended on advice of the independent Data Safety Monitoring Board because of an imbalance in mortality after a total enrollment of 567 patients. The groups were well matched for initial stroke severity and time from stroke onset to therapy. There was no difference in the 90-day mortality rate, with 62 deaths (22%) in the Selfotel group and 49 (17%) in the placebo-treated group (RR=1.3; 95% CI 0.92 to 1.83; P=0.15). However, early mortality was higher in the Selfotel-treated patients (day 30: 54 of 280 versus 37 of 286; P=0.05). In patients with severe stroke, mortality imbalance was significant throughout the trial (P=0.05).

CONCLUSIONS

Selfotel was not an effective treatment for acute ischemic stroke. Furthermore, a trend toward increased mortality, particularly within the first 30 days and in patients with severe stroke, suggests that the drug might have a neurotoxic effect in brain ischemia.