Intravenous dipyrone in the acute treatment of migraine without aura and migraine with aura: a randomized, double blind, placebo controlled study

The effectiveness of parenteral agents to mitigate relapses after severe acute migraine headache presentations: A systematic review and network analysis

OBJECTIVES

To compare the effectiveness of parenteral agents to reduce relapse in patients with acute migraine and identify factors that predict relapse.

BACKGROUND

Following discharge from emergency settings, many patients with acute migraine will experience a relapse in pain; severe relapses may result in re-visits to emergency settings.

METHODS

A comprehensive literature search, updated to 2023, was conducted to identify randomized controlled trials assessing the effectiveness of parenteral agents on relapse outcomes in patients with acute migraine discharged from emergency settings. Two independent reviewers completed study selection, quality assessment, and data extraction. A traditional meta-analysis compared parenteral corticosteroids to placebo; a frequentist network analysis assessed direct and indirect comparisons. Results are reported as risk ratios (RRs) and 95% confidence intervals (CIs). The review protocol was registered with the International Prospective Register of Systematic Reviews (identifier: CRD42018099493).

RESULTS

From 8949 citations, a total of 53 unique studies were included involving 6167 patients. Most studies had a high or unclear risk of bias. Corticosteroids significantly reduced relapses compared to placebo (RR 0.67, 95% CI 0.52-0.88; I2 = 0%). Patients receiving lidocaine (RR 0.10, 95% CI 0.01-0.82), sedatives/hypnotics (RR 0.33, 95% CI 0.14-0.75), ergot agents (RR 0.44, 95% CI 0.25-0.75), neuroleptics (RR 0.47, 95% CI 0.31-0.71), opioids (RR 0.58; 95% CI 0.35-0.94), or corticosteroids (RR 0.64, 95% CI 0.47-0.86) were significantly less likely to relapse. Lidocaine (RR 0.09, 95% CI 0.01-0.71), combination therapy (RR 0.12, 95% CI 0.02-0.74), or adding corticosteroids (RR 0.61, 95% CI 0.44-0.84) were more likely to reduce severe relapses. Longer duration of headache and residual pain at discharge were significantly associated with higher relapses.

DISCUSSION

Corticosteroids remain the recommended first-line option to reduce relapse outcomes. Some parenteral agents typically provided for pain relief including ergot agents, neuroleptics, or combination therapy may effectively reduce relapse; however, opioids are not recommended due to safety concerns. Additional research is needed for some lesser studied, albeit promising, agents including lidocaine and propofol. Effective pain control in emergency settings prior to discharge and duration of headache may play a role in the success of such treatments and further investigations could provide further insight regarding how and why some parenteral agents are effective in mitigating relapse events.

The effectiveness of parenteral agents for pain reduction in patients with migraine presenting to emergency settings: A systematic review and network analysis

OBJECTIVES

To assess the comparative effectiveness and safety of parenteral agents for pain reduction in patients with acute migraine.

BACKGROUND

Parenteral agents have been shown to be effective in treating acute migraine pain; however, the comparative effectiveness of different approaches is unclear.

METHODS

Nine electronic databases and gray literature sources were searched to identify randomized clinical trials assessing parenteral agents to treat acute migraine pain in emergency settings. Two independent reviewers completed study screening, data extraction, and Cochrane risk-of-bias assessment, with differences being resolved by adjudication. The protocol of the review was registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42018100096).

RESULTS

A total of 97 unique studies were included, with most studies reporting a high or unclear risk of bias. Monotherapy, as well as combination therapy, successfully reduced pain scores prior to discharge. They also increased the proportion of patients reporting pain relief and being pain free. Across the pain outcomes assessed, combination therapy was one of the higher ranked approaches and provided robust improvements in pain outcomes, including lowering pain scores (mean difference -3.36, 95% confidence interval [CI] -4.64 to -2.08) and increasing the proportion of patients reporting pain relief (risk ratio [RR] 2.83, 95% CI 1.74-4.61). Neuroleptics and metoclopramide also ranked high in terms of the proportion of patients reporting pain relief (neuroleptics RR 2.76, 95% CI 2.12-3.60; metoclopramide RR 2.58, 95% CI 1.90-3.49) and being pain free before emergency department discharge (neuroleptics RR 4.8, 95% CI 3.61-6.49; metoclopramide RR 4.1, 95% CI 3.02-5.44). Most parenteral agents were associated with increased adverse events, particularly combination therapy and neuroleptics.

CONCLUSIONS

Various parenteral agents were found to provide effective pain relief. Considering the consistent improvements across various outcomes, combination therapy, as well as monotherapy of either metoclopramide or neuroleptics are recommended as first-line options for managing acute migraine pain. There are risks of adverse events, especially akathisia, following treatment with these agents. We recommend that a shared decision-making model be considered to effectively identify the best treatment option based on the patient's needs.

Comparison between metamizole and triptans for migraine treatment: a systematic review and network meta-analysis

Objective The aim of this systematic review was to evaluate the efficacy of metamizole and triptans for the treatment of migraine. MethodsRandomized controlled trials including people who received metamizole or triptan by multiple routes of administration and at all doses as treatment compared to subjects who received another treatment or placebo were included in the systematic review. The primary outcomes were freedom from pain at 2 hours; pain relief at 2 hours; sustained headache response at 24 hours; sustained freedom from pain at 24 hours. The statistical analysis of all interventions of interest were based on random effect models compared through a network meta-analysis. Results 209 studies meeting the inclusion and exclusion criteria were analyzed. Of these, 130 had data that could be analyzed statistically. Only 3.0% provided enough information and were judged to have a low overall risk of bias for all categories evaluated; approximately 50% of the studies presented a low risk of selection bias. More than 75% of the studies presented a low risk of performance bias, and around 75% showed a low risk of detection and attrition bias. ConclusionThere is no evidence of a difference between dipyrone and any triptan for pain freedom after 2 hours of medication. Our study suggests that metamizole may be equally effective as triptans in acute migraine treatment.

Comprehensive management of adults with chronic migraine: Clinical practice guidelines in Mexico

Introduction:

Migraine is a polygenic multifactorial disorder with a neuronal initiation of a cascade of neurochemical processes leading to incapacitating headaches. Headaches are generally unilateral, throbbing, 4–72 h in duration, and associated with nausea, vomiting, photophobia, and sonophobia. Chronic migraine (CM) is the presence of a headache at least 15 days per month for ≥3 months and has a high global impact on health and economy, and therapeutic guidelines are lacking.

Methods:

Using the Grading of Recommendations, Assessment, Development, and Evaluations system, we conducted a search in MEDLINE and Cochrane to investigate the current evidence and generate recommendations of clinical practice on the identification of risk factors and treatment of CM in adults.

Results:

We recommend avoiding overmedication of non-steroidal anti-inflammatory drugs (NSAIDs); ergotamine; caffeine; opioids; barbiturates; and initiating individualized prophylactic treatment with topiramate eptinezumab, galcanezumab, erenumab, fremanezumab, or botulinum toxin. We highlight the necessity of managing comorbidities initially. In the acute management, we recommend NSAIDs, triptans, lasmiditan, and gepants alone or with metoclopramide if nausea or vomiting. Non-pharmacological measures include neurostimulation.

Conclusions:

We have identified the risk factors and treatments available for the management of CM based on a grading system, which facilitates selection for individualized management.

Utilization of Magnesium for the Treatment of Chronic Pain

CONTEXT

The International Association for the Study of Pain (IASP) defines chronic pain as pain that persists or recurs for longer than 3 months. Chronic pain has a significant global disease burden with profound effects on health, quality of life, and socioeconomic costs.

EVIDENCE ACQUISITION

Narrative review.

RESULTS

There are several treatment options, including pharmacological therapy, physical rehabilitation, psychological therapies, and surgical interventions, for chronic pain management. Magnesium has been FDA-approved for several indications including hypomagnesemia, arrhythmia, prevention of seizures in eclampsia/preeclampsia, and constipation. Magnesium has been used for numerous off-label uses, notably for acute and chronic pain management. The mechanism of magnesium in pain management is primarily through its action as a voltage-gated antagonist of NMDA receptors, which are involved in pain transduction.

CONCLUSIONS

This narrative review will focus on the current evidence and data surrounding the utilization of magnesium as a treatment option for chronic pain.

Differences in treatment response between migraine with aura and migraine without aura: lessons from clinical practice and RCTs

Migraine is a major public health problem afflicting approximately 10% of the general population and is a leading cause of disability worldwide, yet our understanding of the basis mechanisms of migraine remains incomplete. About a third of migraine patients have attacks with aura, consisting of transient neurological symptoms that precede or accompany headache, or occur without headache. For patients, aura symptoms are alarming and may be transiently disabling. For clinicians and scientists, aura represents an intriguing neurophysiological event that may provide important insight into basic mechanisms of migraine. Several observations point toward important differences between migraine with and without aura. Compared with migraine without aura, migraine with aura has different heritability, greater association with different conditions including stroke, different alterations of brain structure and function as revealed by imaging studies. A number of studies also indicate that migraine with aura may respond differently to acute and preventive therapies as compared to migraine without aura. The purpose of this review is to provide an overview of these differences in treatment responses, and to discuss the possibility of different therapeutic strategies for migraine with vs. without aura.

TRPA1/NOX in the soma of trigeminal ganglion neurons mediates migraine-related pain of glyceryl trinitrate in mice

Glyceryl trinitrate is administered as a provocative test for migraine pain. Glyceryl trinitrate causes prolonged mechanical allodynia in rodents, which temporally correlates with delayed glyceryl trinitrate-evoked migraine attacks in patients. However, the underlying mechanism of the allodynia evoked by glyceryl trinitrate is unknown. The proalgesic transient receptor potential ankyrin 1 (TRPA1) channel, expressed by trigeminal nociceptors, is sensitive to oxidative stress and is targeted by nitric oxide or its by-products. Herein, we explored the role of TRPA1 in glyceryl trinitrate-evoked allodynia. Systemic administration of glyceryl trinitrate elicited in the mouse periorbital area an early and transient vasodilatation and a delayed and prolonged mechanical allodynia. The systemic, intrathecal or local administration of selective enzyme inhibitors revealed that nitric oxide, liberated from the parent drug by aldehyde dehydrogenase 2 (ALDH2), initiates but does not maintain allodynia. The central and the final phases of allodynia were respectively associated with generation of reactive oxygen and carbonyl species within the trigeminal ganglion. Allodynia was absent in TRPA1-deficient mice and was reversed by TRPA1 antagonists. Knockdown of neuronal TRPA1 by intrathecally administered antisense oligonucleotide and selective deletion of TRPA1 from sensory neurons in Advillin-Cre; Trpa1^fl/fl mice revealed that nitric oxide-dependent oxidative and carbonylic stress generation is due to TRPA1 stimulation, and resultant NADPH oxidase 1 (NOX1) and NOX2 activation in the soma of trigeminal ganglion neurons. Early periorbital vasodilatation evoked by glyceryl trinitrate was attenuated by ALDH2 inhibition but was unaffected by TRPA1 blockade. Antagonists of the calcitonin gene-related peptide receptor did not affect the vasodilatation but partially inhibited allodynia. Thus, although both periorbital allodynia and vasodilatation evoked by glyceryl trinitrate are initiated by nitric oxide, they are temporally and mechanistically distinct. While vasodilatation is due to a direct nitric oxide action in the vascular smooth muscle, allodynia is a neuronal phenomenon mediated by TRPA1 activation and ensuing oxidative stress. The autocrine pathway, sustained by TRPA1 and NOX1/2 within neuronal cell bodies of trigeminal ganglia, may sensitize meningeal nociceptors and second order trigeminal neurons to elicit periorbital allodynia, and could be of relevance for migraine-like headaches evoked by glyceryl trinitrate in humans.

Treatment of migraine attacks and prevention of migraine: Guidelines by the German Migraine and Headache Society and the German Society of Neurology

In collaboration with some of the leading headache centres in Germany, Switzerland and Austria, we have established new guidelines for the treatment of migraine attacks and the prevention of migraine. A thorough literature research of the last 10 years has been the basis of the current recommendations. At the beginning, we present therapeutic novelties, followed by a summary of all recommendations. After an introduction, we cover topics like drug therapy and practical experience, non-effective medication, migraine prevention, interventional methods, non-medicational and psychological methods for prevention and therapies without proof of efficacy.

Pathways of CGRP Release from Primary Sensory Neurons

The benefit reported in a variety of clinical trials by a series of small molecule antagonists for the calcitonin gene-related peptide (CGRP) receptor, or four monoclonal antibodies against the neuropeptide or its receptor, has underscored the release of CGRP from terminals of primary sensory neurons, including trigeminal neurons, as one of the major mechanisms of migraine headaches. A large variety of excitatory ion channels and receptors have been reported to elicit CGRP release, thus proposing these agonists as migraine-provoking agents. On the other side, activators of inhibitory channels and receptors may be regarded as potential antimigraine agents. The knowledge of the intracellular pathways underlying the exocytotic process that results in CGRP secretion or its inhibition is, therefore, of importance for understanding how migraine pain originates and how to treat the disease.

The anti-migraine component of butterbur extracts, isopetasin, desensitizes peptidergic nociceptors by acting on TRPA1 cation channel

BACKGROUND AND PURPOSE

The mechanism of the anti-migraine action of extracts of butterbur [Petasites hybridus (L.) Gaertn.] is unknown. Here, we investigated the ability of isopetasin, a major constituent of these extracts, to specifically target TRPA1 channel and to affect functional responses relevant to migraine.

EXPERIMENTAL APPROACH

Single-cell calcium imaging and patch-clamp recordings in human and rodent TRPA1-expressing cells, neurogenic motor responses in rodent isolated urinary bladder, release of CGRP from mouse spinal cord in vitro and facial rubbing in mice and meningeal blood flow in rats were examined.

KEY RESULTS

Isopetasin induced (i) calcium responses and currents in rat/mouse trigeminal ganglion (TG) neurons and in cells expressing the human TRPA1, (ii) substance P-mediated contractions of rat isolated urinary bladders and (iii) CGRP release from mouse dorsal spinal cord, responses that were selectively abolished by genetic deletion or pharmacological antagonism of TRPA1 channels. Pre-exposure to isopetasin produced marked desensitization of allyl isothiocyanate (AITC, TRPA1 channel agonist)- or capsaicin (TRPV1 channel agonist)-evoked currents in rat TG neurons, contractions of rat or mouse bladder and CGRP release from mouse central terminals of primary sensory neurons. Repeated intragastric administration of isopetasin attenuated mouse facial rubbing, evoked by local AITC or capsaicin, and dilation of rat meningeal arteries by acrolein or ethanol (TRPA1 and TRPV1 channel agonists respectively).

CONCLUSION AND IMPLICATIONS

Activation of TRPA1 channels by isopetasin results in excitation of neuropeptide-containing nociceptors, followed by marked heterologous neuronal desensitization. Such atten uation in pain and neurogenic inflammation may account for the anti-migraine action of butterbur.

Management of Adults With Acute Migraine in the Emergency Department: The American Headache Society Evidence Assessment of Parenteral Pharmacotherapies

OBJECTIVE

To provide evidence-based treatment recommendations for adults with acute migraine who require treatment with injectable medication in an emergency department (ED). We addressed two clinically relevant questions: (1) Which injectable medications should be considered first-line treatment for adults who present to an ED with acute migraine? (2) Do parenteral corticosteroids prevent recurrence of migraine in adults discharged from an ED?

METHODS

The American Headache Society convened an expert panel of authors who defined a search strategy and then performed a search of Medline, Embase, the Cochrane database and clinical trial registries from inception through 2015. Identified articles were rated using the American Academy of Neurology's risk of bias tool. For each medication, the expert panel determined likelihood of efficacy. Recommendations were created accounting for efficacy, adverse events, availability of alternate therapies, and principles of medication action.

RESULTS/CONCLUSIONS

The search identified 68 unique randomized controlled trials utilizing 28 injectable medications. Of these, 19 were rated class 1 (low risk of bias), 21 were rated class 2 (higher risk of bias), and 28 were rated class 3 (highest risk of bias). Metoclopramide, prochlorperazine, and sumatriptan each had multiple class 1 studies supporting acute efficacy, as did dexamethasone for prevention of headache recurrence. All other medications had lower levels of evidence.

RECOMMENDATIONS

Intravenous metoclopramide and prochlorperazine, and subcutaneous sumatriptan should be offered to eligible adults who present to an ED with acute migraine (Should offer-Level B). Dexamethasone should be offered to these patients to prevent recurrence of headache (Should offer-Level B). Because of lack of evidence demonstrating efficacy and concern about sub-acute or long-term sequelae, injectable morphine and hydromorphone are best avoided as first-line therapy (May avoid-Level C).

Metamizole-associated adverse events: a systematic review and meta-analysis

Background

Metamizole is used to treat pain in many parts of the world. Information on the safety profile of metamizole is scarce; no conclusive summary of the literature exists.

Objective

To determine whether metamizole is clinically safe compared to placebo and other analgesics.

Methods

We searched CENTRAL, MEDLINE, EMBASE, CINAHL, and several clinical trial registries. We screened the reference lists of included trials and previous systematic reviews. We included randomized controlled trials that compared the effects of metamizole, administered to adults in any form and for any indication, to other analgesics or to placebo. Two authors extracted data regarding trial design and size, indications for pain medication, patient characteristics, treatment regimens, and methodological characteristics. Adverse events (AEs), serious adverse events (SAEs), and dropouts were assessed. We conducted separate meta-analyses for each metamizole comparator, using standard inverse-variance random effects meta-analysis to pool the estimates across trials, reported as risk ratios (RRs). We calculated the DerSimonian and Laird variance estimate T² to measure heterogeneity between trials. The pre-specified primary end point was any AE during the trial period.

Results

Of the 696 potentially eligible trials, 79 trials including almost 4000 patients with short-term metamizole use of less than two weeks met our inclusion criteria. Fewer AEs were reported for metamizole compared to opioids, RR = 0.79 (confidence interval 0.79 to 0.96). We found no differences between metamizole and placebo, paracetamol and NSAIDs. Only a few SAEs were reported, with no difference between metamizole and other analgesics. No agranulocytosis or deaths were reported. Our results were limited by the mediocre overall quality of the reports.

Conclusion

For short-term use in the hospital setting, metamizole seems to be a safe choice when compared to other widely used analgesics. High-quality, adequately sized trials assessing the intermediate- and long-term safety of metamizole are needed.

The visual system in migraine: from the bench side to the office

BACKGROUND

Throughout history, migraine-associated visual symptoms have puzzled patients, doctors, and neuroscientists. The visual aspects of migraine extend far beyond the aura phenomena, and have several clinical implications.

METHODS

A narrative review was conducted, beginning with migraine mechanisms, then followed by pertinent aspects of the anatomy of visual pathways, clinical features, implications of the visual system on therapy, migraine on visually impaired populations, treatment of visual auras and ocular (retinal) migraine, effect of prophylactic migraine treatments on visual aura, visual symptoms induced by anti-migraine or anti-headache drugs, and differential diagnosis.

RESULTS

A comprehensive narrative review from both basic and clinical standpoints on the visual aspects of migraine was attained; however, the results were biased to provide any useful information for the clinician.

CONCLUSION

This paper achieved its goals of addressing and condensing information on the pathophysiology of the visual aspects of migraine and its clinical aspects, especially with regards to therapy, making it useful not only for those unfamiliar to the theme but to experienced physicians as well.

WITHDRAWN: Dipyrone for acute primary headaches

The original authors of this review are unable to update it. The Cochrane Pain, Palliative and Supportive Care Review Group (PaPaS) is seeking new authors to update and split the review into two separate reviews on migraine and tension‐type headache. If you are interested, please contact the Managing Editor of PaPaS (contact details provided under 'Contact Person').

At July 2014, this review has been withdrawn. This review is out of date although it is correct as of the date of publication. The latest version is available in the ‘Other versions’ tab on The Cochrane Library, and may still be useful to readers.

The editorial group responsible for this previously published document have withdrawn it from publication.

Intravenous lysine clonixinate for the acute treatment of severe migraine attacks: a double-blind, randomized, placebo-controlled study

BACKGROUND

Several nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to be effective in the treatment of migraine. However, few commercially available NSAIDs can be administered IV. Lysine clonixinate (LC), an NSAID derived from nicotinic acid, has been proved effective in various algesic syndromes (eg, renal colic, muscular pain, nerve compression, odontalgia). The oral formulation of LC has been shown to be effective in the treatment of migraine of moderate severity.

OBJECTIVE

The aim of this study was to assess the efficacy and tolerability of the IV formulation of LC in the treatment of severe migraine.

METHODS

This double-blind, randomized, placebo-controlled, prospective study enrolled patients with severe migraine (without aura) as defined by the criteria of the International Headache Society. When patients presented to a neurology hospital with an outpatient headache unit (Instituto de Neurologia Deolindo Couto, Rio de Janeiro, Brazil) with a severe migraine attack that had lasted <4 hours, they were randomized to 1 of 2 groups (IV placebo [25 mL of 0.9% saline] or IV LC [21 mL of 0.9% saline plus 4 mL of LC 200 mg]). Headache intensity and adverse effects (AEs) were assessed before (0 minute) and 30, 60, and 90 minutes after study drug administration. Rescue medication was available 2 hours after study drug administration, and its use was compared between groups.

RESULTS

Thirty-two patients (23 women, 9 men; mean [SD] age, 32 [2] years; range, 18-58 years) entered the study. Twenty-nine patients (21 women, 8 men; mean [SD] age, 32 [2] years; range, 18-56 years) completed the study. Three patients (all in the placebo group) did not complete the study (1 patient was unable to rate the pain severity after drug administration and 2 patients refused IV drug administration). Among study completers, 17 patients received LC and 12 placebo. At 30 minutes, 1 patient (8.3%) in the placebo group and 5 patients (29.4%) in the LC group were pain free; the between-group difference was not statistically significant. At 60 and 90 minutes, respectively, 3 (25.0%) and 5 (41.7%) patients in the placebo group and 12 (70.6%) and 14 (82.4%) patients in the LC group were pain free (P = 0.021 and P = 0.028 between groups at 60 and 90 minutes, respectively). Six patients (50.0%) in the placebo group and 1 patient (5.9%) in the LC group required rescue medication at 2 hours (P = 0.010 between groups). Three patients (25.0%) in the placebo group experienced AEs, including vomiting, dizziness, and malaise (1 patient [8.3%] each); 11 patients (64.7%) in the LC group experienced 1 AE, including burning pain at the injection site (5 patients [29.4%]), heartburn (4 patients [23.5%]), and dizziness and malaise (1 patient [5.9%] each) (P = 0.025).

CONCLUSIONS

NSAIDs administered by the IV route cannot be used routinely in an outpatient environment, although an attempt to improve drugs in this class is clearly justified. This study demonstrated that IV LC was effective and well tolerated in the treatment of severe migraine attacks. This finding differs from results with the oral formulation, which is effective only in migraine of moderate severity.

Effects of intravenous metamizole on ongoing and evoked activity of dura-sensitive thalamic neurons in rats

Migraine and tension-type headache (TTH) are the most common forms of primary headaches. A general key mechanism underlying development of both the diseases is the trigeminal system activation associated with the ascending nociceptive transmission via the trigemino-thalamo-cortical pathway. The ventroposteromedial (VPM) nucleus is a key thalamic structure, receiving afferent inflow from the craniofacial region; it holds the third-order neurons responsible for conveying sensory information from the extra- and intracranial nociceptors to the cortex. The VPM is currently seen as a therapeutic target for various antimigraine medications, which is shown to reduce the VPM neuronal excitability. A non-opioid analgesic metamizole is widely used in some countries for acute treatment of migraine or TTH. However, the precise mechanisms underlying anticephalgic action of metamizole remain unclear. The objective of our study performed in the rat model of trigemino-durovascular nociception was to evaluate the effects of intravenously administered metamizole on ongoing and evoked firing of the dura-sensitive VPM neurons. The experiments were carried out on rats under urethane-chloralose anesthesia. Cumulative administration of metamizole (thrice-repeated intravenous infusion of 150 mg/kg performed 30 min apart) in 56% of cases produced a suppression of both the ongoing activity of the thalamic VPM neurons and their responses to dural electrical stimulation. Although the inhibitory effect was prevailing, a number of VPM neurons were indifferent to the administration of metamizole. These data suggest that one of the main components of neural mechanism underlying anticephalgic action of metamizole is suppression of the thalamo-cortical nociceptive transmission associated with trigemino-vascular activation.

Italian guidelines for primary headaches: 2012 revised version

The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105-190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version.

Are the current IHS guidelines for migraine drug trials being followed?

In 2000, the Clinical Trials Subcommittee of the International Headache Society (IHS) published the second edition of its guidelines for controlled trials of drugs in migraine. The purpose of this publication was to improve the quality of such trials by increasing the awareness amongst investigators of the methodological issues specific to this particular illness. Until now the adherence to these guidelines has not been systematically assessed. We reviewed all published controlled trials of drugs in migraine from 2002 to 2008. Eligible trials were scored for compliance with the IHS guidelines by using grading scales based on the most essential recommendations of the guidelines. The primary efficacy measure of each trial was also recorded. A total of 145 trials of acute treatment and 52 trials of prophylactic treatment were eligible for review. Of the randomized, double-blind trials, acute trials scored an average of 4.7 out of 7 while prophylactic trials scored an average of 5.6 out of 9 for compliance. Thirty-one percent of acute trials and 72% of prophylactic trials used the recommended primary efficacy measure. Fourteen percent of the reviewed trials were either not randomized or not double-blinded. Adherence to international guidelines like these of IHS is important to ensure that only high-quality trials are performed, and to provide the consensus that is required for meta analyses. The primary efficacy measure for trials of acute treatment should be “pain free” and not “headache relief”. Open-label or non-randomized trials generally have no place in the study of migraine drugs.

Quantification of 4-methylaminoantipyrine, the active metabolite of dipyrone, in human plasma

Background: Dipyrone (metamizole) is a nonsteroidal anti-inflammatory drug used as an analgesic and antipyretic in both pediatric and adult patients. Dipyrone hydrolyses to 4-methylaminoantipyrine (MAA) in the stomach before absorption. There are several HPLC methods available for analysis of MAA from human plasma but no method has yet been developed on liquid chromatography–mass spectrometry (LC–MS) or LC tandem MS (LC–MS/MS), which are much more specific and sensitive techniques. Methodology: A high-performance LC–MS method for the quantification of 4-methylaminoantipyrine from human plasma has been developed, validated and applied to a pharmacokinetic study of 500 mg oral dose dipyrone. Following liquid–liquid extraction, the analyte was first separated on a reverse phase column using isocratic mobile phase and then analyzed by MS in selected ion monitoring mode using [M+H]+ ions, m/z 218.2 for 4-methylaminoantipyrine and 231.3 for 4-isopropylantipyrine (internal standard). Results: The method exhibited a linear range from 0.2 to10.0 µg/ml when only 100 µl human plasma sample was used. The lower limit of detection was 0.04 µg/ml (160 pg on column). The recovery was 80%. The accuracy and precision were obtained over the calibration curve range and were well within the limits specified under guidelines for bioanalytical method validation. The compound was stable under the experimental conditions. Conclusion: The method was demonstrated to be, simple, sensitive and rapid. It can be easily adopted in laboratories with access to LC–MS or MS/MS and applied to sample analysis in clinical settings where a large number of samples are generated.

Lysine clonixinate versus dipyrone (metamizole) for the acute treatment of severe migraine attacks: a single-blind, randomized study

BACKGROUND AND OBJECTIVE: Nonsteroidal anti-inflammatory drugs (NSAID) are effective to treat migraine attacks. Lysine clonixinate (LC) and dipyrone (metamizol) have been proven effective to treat acute migraine. The aim of this study was to evaluate the efficacy and tolerability of the intravenous formulations of LC and dipyrone in the treatment of severe migraine attacks. METHOD: Thirty patients (28 women, 2 men), aged 18 to 48 years with migraine according the International Headache Society (IHS) (2004) were studied. The patients were randomized into 2 groups when presenting to an emergency department with a severe migraine attack. The study was single-blind. Headache intensity, nausea, photophobia and side effects were evaluated at 0, 30, 60 and 90 minutes after the drug administration. Rectal indomethacin as rescue medication (RM) was available after 2 hours and its use compared between groups. RESULTS: All patients completed the study. At 30 minutes, 0% of the dipyrone group 13% of the LC group were pain free (p=0.46). At 60 and 90 minutes, 2 (13%) and 5 (33%) patients from the dipyrone group and 11 (73%) and 13 (86.7%) patients from the LC group were pain free (p<0.001). At 60 minutes, significantly more patients from the LC group were nausea-free (p<0.001). Regarding photophobia, there were no differences between groups at 60 minutes (p=0.11). The use of RM at 2 hours did not differ among groups (p=0.50). Pain in the site of the injection was reported by more patients of the LC group compared to the dipyrone group (p<0.0001). CONCLUSION: LC is significantly superior to dipyrone in treating severe migraine attacks. LC promotes significantly more burning at the site of the injection.

Dipyrone for acute primary headaches

BACKGROUND

Dipyrone is used to treat headaches in many countries, but is not available in others (particularly the USA and UK) because of its association with potentially life-threatening blood dyscrasias such as agranulocytosis.

OBJECTIVES

To determine the effectiveness and safety of dipyrone for acute primary headaches in adults and children.

SEARCH STRATEGY

We searched the Cochrane Pain, Palliative & Supportive Care Group's Trials Register; the Cochrane Central Register of Controlled Trials; MEDLINE; EMBASE; LILACS, and the reference lists of included studies.

SELECTION CRITERIA

Double-blind randomised controlled trials of dipyrone for the symptomatic relief of acute primary headaches in adults and children.

DATA COLLECTION AND ANALYSIS

Three authors independently screened articles, extracted data, assessed trial quality and analysed results. Relative risks (RRs), risk differences (RDs), weighted mean differences (WMDs), and numbers-needed-to-treat (NNTs) were calculated as appropriate.

MAIN RESULTS

Four trials involving a total of 636 adult subjects were included. Methodological quality was generally high. One study each evaluated oral and intravenous dipyrone for episodic tension-type headache (ETTH); two trials evaluated intravenous dipyrone for migraine, but only one of these described pain outcomes. No pediatric trials were identified. The largest trial (n = 356) evaluated two doses (0.5 g, 1 g) of oral dipyrone for ETTH, which were significantly better than placebo for pain relief. The 1 g dose was also significantly better than acetylsalicylic acid (ASA) 1 g . A smaller trial (n = 60) evaluated intravenous dipyrone 1 g versus placebo for ETTH. RRs were statistically significant favouring dipyrone for pain-free and headache improvement outcomes. Finally, one trial (n = 134) evaluated intravenous dipyrone 1 g versus placebo for pain outcomes in patients with migraine. RRs were again statistically significant favouring dipyrone for pain-free and headache improvement outcomes. Two of the four trials assessed adverse events. No serious adverse events were reported, and no significant differences in adverse events were detected between dipyrone and comparators (placebo and ASA).

AUTHORS' CONCLUSIONS

Evidence from a small number of trials suggests that dipyrone is effective for ETTH and migraine. No serious adverse events were observed in the included trials, but agranulocytosis is rare and would probably not be observed in such a relatively small sample. A study now ongoing in Latin America may clarify the true risk of agranulocytosis associated with dipyrone use.

Comparação de dipirona intravenosa com metoclopramida intravenosa no tratamento de crise aguda de enxaqueca: ensaio clínico randomizado

INTRODUÇÃO: A enxaqueca é uma das doenças mais comuns da prática clínica. OBJETIVO: Comparar o efeito analgésico da dipirona com a metoclopramida no alívio da dor. MÉTODO: Conduzimos um estudo piloto randomizado comparando dipirona intravenosa com metoclopramida intravenosa em 27 pacientes apresentando crise de enxaqueca. O objetivo primário foi comparar a redução da intensidade da dor até 2 horas, assim como efeitos colaterais. RESULTADOS: Os grupos tinham faixas etárias semelhantes, mas diferença entre os sexos. Nos homens a metoclopramida reduziu a dor em 80,0% contra 55,0% da dipirona (p=0,052). Já nas mulheres houve uma redução de 65,0% com a metoclopramida e 71,2% com a dipirona (p=0,748). Esses resultados podem ter sido influenciados pelo reduzido número de pacientes no estudo. Não foram encontrados efeitos colaterais significativos. CONCLUSÃO: Não houve diferença quanto à redução da dor nem quanto ao surgimento de efeitos colaterais quando comparados dipirona com metoclopramida.

EFNS guideline on the drug treatment of migraine - report of an EFNS task force

Migraine is one of the most frequent disabling neurological conditions with a major impact on the patients' quality of life. To give evidence-based or expert recommendations for the different drug treatment procedures of the different migraine syndromes based on a literature search and an consensus in an expert panel. All available medical reference systems were screened for all kinds of clinical studies on migraine with and without aura and on migraine-like syndromes. The findings in these studies were evaluated according to the recommendations of the EFNS resulting in level A,B, or C recommendations and good practice points. For the acute treatment of migraine attacks, oral non-steroidal anti-inflammatory drugs (NSAIDs) and triptans are recommended. The administration should follow the concept of stratified treatment. Before intake of NSAIDs and triptans, oral metoclopramide or domperidon is recommended. In very severe attacks, intravenous acetylsalicylic acid or subcutaneous sumatriptan are drugs of first choice. A status migrainosus can probably be treated by steroids. For the prophylaxis of migraine, betablockers (propranolol and metoprolol), flunarizine, valproic acid, and topiramate are drugs of first choice. Drugs of second choice for migraine prophylaxis are amitriptyline, naproxen, petasites, and bisoprolol.

[Acute treatment of migraine in emergency room: comparative study between dexametasone and haloperidol. Preliminary results]

We studied the efficacy of dexamethasone (4 mg) and haloperidol (5 mg) in the treatment of migraine in the emergency room. Twenty nine patients who had diagnosis of migraine according to the International Headache Society criteria and were evaluated for a painful episode at the emergency room of Santa Casa of São Paulo were included. All the patients scored their pain in 10 when evaluated, even after the use of intravenous analgesia (dipyrone). Fourteen patients were treated with haloperidol and the remaining 15 received dexamethasone. The patients were asked about pain intensity at 30, 60, 90 and 120 minutes after the use of either the drugs. Both drugs were equally efficient in pain relief after two hours. Patients who were treated with haloperidol showed an important improvement (more than 50% of improve in the analogic pain scale) in the first 30 minutes. The dexamethasone treated patients only reached this grade of analgesia after 120 minutes. Although we studied a small series of patients, our data suggest that both drugs are efficient in the treatment of a refractory migraine attack. Haloperidol seemed to work quickly in pain relief. No important side effects were observed in neither groups.

Migraine: an ophthalmologist's perspective

PURPOSE OF REVIEW

Migraine is a common disorder with visual and neurologic manifestations. Many patients present to ophthalmologists without a previous diagnosis of migraine. It is therefore essential for the ophthalmologist to have a good understanding of migraine to appropriately help these patients. Neurologic syndromes with migraine and retinopathy are well known. Here again, the ophthalmologist may play a role in establishing the correct diagnosis.

RECENT FINDINGS

For long the initial changes during a migraine attack have been shown to occur in the occipital cortex. In the recent years, the understanding of migraine has advanced with the availability of functional neuroimaging. A possible role of brainstem structures in the initiation of migraine attacks has been proposed based on functional magnetic resonance imaging blood oxygenation level-dependent signals. Activation of brainstem structures preceded activation of occipital cortex. Our understanding of cortical spreading depression is also advancing. Using multiwavelength optical intrinsic imaging, cortical spreading depression has been shown to have a triphasic response in rats. For the first time it has been shown that the cortical spreading depression activated the trigeminovascular system, which is followed by a series of cortical meningeal and brainstem events that cause the migraine headache. Sildenafil has been shown to induce migraine attack without dilation of cerebral blood vessels, further confirming that Wolf's vasogenic theory may not be true. Several loci for migraine have been identified in recent years. A new locus for migraine with and without aura has been identified on chromosome 6, a locus for migraine without aura to chromosome 14, and a locus for migraine with aura on chromosome 4.

SUMMARY

Our understanding of migraine is rapidly evolving with functional neuroimaging. There are several unanswered questions. In this article, we will review the epidemiology, genetics, and clinical features of various forms of migraine with emphasis on ocular migraine, pathogenesis, and briefly the management of migraine.