Valproic acid is effective in migraine prophylaxis at low serum levels: a prospective open-label study

Photochemical Action Plots Map Orthogonal Reactivity in Photochemical Release Systems

The wavelength-by-wavelength resolved photoreactivity of two photo-caged carboxylic acids, i. e. 7-(diethylamino)-coumarin- and 3-perylene-modified substrates, is investigated via photochemical action plots. The observed wavelength-dependent reactivity of the chromophores is contrasted with their absorption profile. The photochemical action plots reveal a remarkable mismatch between the maximum reactivity and the absorbance. Through the action plot data, the study is able to uncover photochemical reactivity maxima at longer and shorter wavelengths, where the molar absorptivity of the chromophores is strongly reduced. Finally, the laser experiments are translated to light emitting diode (LED) irradiation and show efficient visible-light-induced release in a near fully wavelength-orthogonal, sequence-independent fashion (λLED1 = 405 nm, λLED2 = 505 nm) with both chromophores in the same reaction solution. The herein pioneered wavelength orthogonal release systems open an avenue for releasing two different molecular cargos with visible light in a fully orthogonal fashion.

Assessment of need for hemostatic evaluation in patients taking valproic acid: A retrospective cross-sectional study

INTRODUCTION

Valproic acid (VPA) is a frequently prescribed anti-epileptic drug. Since its introduction side effects on hemostasis are reported. However, studies show conflicting results, and the clinical relevance is questioned. We aimed to determine the coagulopathies induced by VPA in patients who undergo high-risk surgery. The study results warrant attention to this issue, which might contribute to reducing bleeding complications in future patients.

METHODS

Between January 2012 and August 2020, 73 consecutive patients using VPA were retrospectively included. Extensive laboratory hemostatic assessment (including platelet function tests) was performed before elective high-risk surgery. Patient characteristics, details of VPA treatment, and laboratory results were extracted from medical records.

RESULTS

46.6% of the patients using VPA (n = 73) showed coagulopathy. Mainly, platelet function disorder was found (36.4%). Thrombocytopenia was seen in 9.6% of the patients. Data suggested that the incidence of coagulopathies was almost twice as high in children as compared to adults and hypofibrinogenemia was only demonstrated in children. No association was found between the incidence of coagulopathies and VPA dosage (mg/kg/day).

CONCLUSION

A considerable number of patients using VPA were diagnosed with coagulopathy, especially platelet function disorder. Further prospective studies are needed to confirm the need for comprehensive laboratory testing before elective high-risk surgery in these patients.

Current Approach to Undifferentiated Headache Management in the Emergency Department

PURPOSE OF REVIEW

To discuss pharmacological interventions in the emergency department (ED) setting for the management of acute primary headache.

RECENT FINDINGS

Acute headache treatment in the ED has seen an expansion in terms of possible pharmacological interventions in recent years. After a thorough evaluation ruling out dangerous causes of headache, providers should take the patient's history, comorbidities, and prior therapy into consideration. Antidopaminergics have an established role in the management of acute, severe, headache with manageable side-effect profiles. However, recent studies suggest anesthetic and anti-epileptic drugs may play roles in headache treatment in the ED. Current literature also suggest steroids as a promising tool for emergency department clinicians combating the readmission of patients with recurrent headaches. Emergency medicine providers must be cognizant of these traditional and emerging therapies in order to optimize the care of headache patients.

Age-Dependent Anti-migraine Effects of Valproic Acid and Topiramate in Rats

Background: Valproic acid (VPA) and topiramate (TPM), initially developed as antiepileptics, are approved for migraine prophylaxis in adults but not children. The differences in their antimigraine mechanism(s) by age remain unclear.

Methods: A migraine model induced by intra-cisternal (i.c.) capsaicin instillation in pediatric (4–5 weeks) and adult (8–9 weeks) rats was pretreated with VPA (30, 100 mg/kg) or TPM (10, 30, 100 mg/kg). Noxious meningeal stimulation by the irritant capsaicin triggered trigeminovascular system (TGVS) activation mimicking migraine condition, which were assessed peripherally by the depletion of calcitonin gene-related peptide (CGRP) in sensory nerve fibers of the dura mater, the increased CGRP immunoreactivity at trigeminal ganglia (TG) and centrally by the number of c-Fos-immunoreactive (c-Fos-ir) neurons in the trigeminocervical complex (TCC). Peripherally, CGRP released from dural sensory nerve terminals of TG triggered pain signal transmission in the primary afferent of trigeminal nerve, which in turn caused central sensitization of the TGVS due to TCC activation and hence contributed to migraine.

Results: In the VPA-treated group, the central responsiveness expressed by reducing the number of c-Fos-ir neurons, which had been increased by i.c. capsaicin, was significant in pediatric, but not adult, rats. Inversely, VPA was effective in peripheral inhibition of elevated CGRP immunoreactivity in the TG and CGRP depletion in the dura mater of adult, but not pediatric, rats. In TPM group, the central responsiveness was significant in both adult and pediatric groups. Peripherally, TPM significantly inhibited capsaicin-induced CGRP expression of TG in adult, but not pediatric, rats. Interestingly, the capsaicin-induced depletion of CGRP in dura was significantly rescued by TPM at high doses in adults, but at low dose in pediatric group.

Conclusion: These results suggest VPA exerted peripheral inhibition in adult, but central suppression in pediatric migraine-rats. In contrast, TPM involves both central and peripheral inhibition of migraine with an optimal therapeutic window in both ages. These findings may clarify the age-dependent anti-migraine mechanism of VPA and TPM, which may guide the development of new pediatric anti-migraine drugs in the future.

Clinical Response to Valproate in Patients with Migraine

Background and Purpose

Valproate is used as a prophylactic drug for migraine, but it is not be effective in all patients. We used medical records to investigate which clinical factors affected the response to valproate in patients with migraine as an original headache, and established a scoring system for predicting the clinical response to prophylactic therapy.

Methods

We investigated clinical factors from the medical records of 95 consistent responders (CRs) and 24 inconsistent responders (IRs) to valproate.

Results

Multivariate stepwise logistic regression analysis revealed that a history of hyperlipidemia and hay fever and the complication of depression or other psychiatric disorder were significant factors that independently contributed to a negative response, with odds ratios of 6.024 [no vs. yes; 95% confidence interval (CI)=1.616–22.222], 2.825 (no vs. yes; 95% CI=1.046–7.634), and 2.825 (no vs. yes; 95% CI=1.052–7.576), respectively. A predictive index (PI) of the clinical response to valproate in patients with migraine was calculated using the regression coefficients of these three factors as an integer, and the index was significantly higher for IRs than for CRs (1.46±1.10 vs. 0.69±0.74, mean±SD, p<0.001).

Conclusions

The obtained PI may represent an appropriate scoring system for predicting the responses in these patients.

Effectiveness and safety of an extended-release tablet of sodium valproate for the prophylactic treatment of migraine: Postmarketing surveillance in Japan

BACKGROUND

Sodium valproate is a standard drug for first-line prophylactic treatment of migraine. However, little information is available of its use in Japanese patients.

AIM

To evaluate the effectiveness and safety of an extended-release tablet of sodium valproate in the prophylactic treatment for Japanese patients with migraine by postmarketing surveillance.

METHODS

This was a prospective, multicenter and non-interventional observation study in routine clinical practice. A total of 1222 patients with migraine of all age groups (aged <10 to ≤80 years) and both sexes (17.3% men and 82.7% women) from 169 sites were enrolled.

RESULTS

Migraine frequency during a 4-week period was reduced from 10.2 ± 6.0 days in 1040 patients to 5.0 ± 4.6 days in 944 patients (P < 0.001): 70.8% of patients experienced remission of migraine by ≥30%, 59.0% by ≥50% and 11.8% by ≥100%. Multivariate analysis and stratification sampling showed that this sodium valproate tablet was the most effective in patients with more migraine days, and complete remission was observed in 29% of patients whose migraine days were less than 3 days per 4 weeks at baseline. The extended-release tablet of sodium valproate reduced migraine intensity and duration of migraine attacks. The incidence of adverse drug reactions was 6.3% (67/1070 patients) and well tolerated. However, four pregnancies were discovered in this survey.

CONCLUSIONS

This first large observation study in Japan suggests that an extended-release tablet of sodium valproate is effective and safe for the prophylactic treatment of patients with migraine in routine clinical practice.

WITHDRAWN: Anticonvulsant drugs for migraine prophylaxis

July 2015: This review has been split and updated in a series of four new reviews (Linde 2013a; Linde 2013b; Linde 2013c; Linde 2013d). Readers are referred to those reviews for updated results. This review will not be updated.

May 2016: This review has now been withdrawn as it has been replaced by the four new titles listed above.

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

Antiepileptics in migraine prophylaxis: an updated Cochrane review

INTRODUCTION

The efficacy of several antiepileptics in the preventive treatment of episodic migraine in adults has been systematically reviewed. Because many trial reports have been published since then, an updated systematic review was warranted.

METHODS

We searched the Cochrane Central Register of Controlled Trials, PubMed/MEDLINE (1966 to January 15, 2013), MEDLINE In-Process (current week, January 15, 2013), and EMBASE (1974 to January 15, 2013) and hand-searched Headache and Cephalalgia through January 2013. Prospective, controlled trials of antiepileptics taken regularly to prevent the occurrence of migraine attacks, to improve migraine-related quality of life, or both, were selected.

RESULTS

Mean headache frequency on topiramate and sodium valproate is significantly lower than placebo. Likewise, topiramate and divalproex demonstrated favorable results for the proportion of subjects with ≥ 50% reduction of migraine attacks. For topiramate, 100 mg and 200 mg outperformed 50 mg, but this was paralleled by a higher adverse event rate. For valproate/divalproex, a dose-effect correlation could not be established. There was no unequivocal evidence of efficacy for any of the other antiepileptics.

CONCLUSION

Topiramate, sodium valproate and divalproex are effective prophylactic treatments for episodic migraine in adults. In contrast to previous reports, there is insufficient evidence to further support the use of gabapentin.

Evidence-based medicine in migraine prevention

Migraine headache is a chronic, painful, disabling and potentially progressive, condition primarily occurring in early and middle adulthood. For many patients, daily activities are impaired by the sudden and unpredictable occurrence of migraine attacks. In recent years, significant progress has been made in the field of migraine treatment. For the acute treatment of migraine attacks, 5-hydroxytryptophan(1B/D) agonists (so called triptans), were the most innovative development, successfully aborting attacks in less than 1 h. The search for innovative drugs usable for migraine prevention, however, was less successful, mainly due to the lack of reliable and predictive animal models. Recently, neuromodulators such as valproic acid and topiramate, initially developed as anticonvulsants, have been shown in large clinical trials to be effective in the prevention of migraine. As for the acute treatment of migraine attacks more than 10 years ago, large clinical trial programs are now setting new standards for evidence-based medicine in migraine prevention. This review summarizes the current options in migraine prevention with special emphasis on clinical trial design and new developments such as topiramate.

Valproate (valproic acid or sodium valproate or a combination of the two) for the prophylaxis of episodic migraine in adults

BACKGROUND

Some antiepileptic drugs but not others are useful in clinical practice for the prophylaxis of migraine. This might be explained by the variety of actions of these drugs in the central nervous system. The present review is part of an update of a Cochrane review first published in 2004, and previously updated (conclusions not changed) in 2007.

OBJECTIVES

To describe and assess the evidence from controlled trials on the efficacy and tolerability of valproate (valproic acid or sodium valproate or a combination of the two) for preventing migraine attacks in adult patients with episodic migraine.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2012, Issue 12), PubMed/MEDLINE (1966 to 15 January 2013), MEDLINE In-Process (current week, 15 January 2013), and EMBASE (1974 to 15 January 2013) and handsearched Headache and Cephalalgia through January 2013.

SELECTION CRITERIA

Studies were required to be prospective, controlled trials of valproate taken regularly to prevent the occurrence of migraine attacks, to improve migraine-related quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. For headache frequency data, we calculated mean differences (MDs) between valproate and comparator (placebo, active control, or valproate in a different dose) for individual studies and pooled these across studies. For dichotomous data on responders (patients with ≥ 50% reduction in headache frequency), we calculated odds ratios (ORs) and, in select cases, risk ratios (RRs); we also calculated numbers needed to treat (NNTs). We calculated MDs for Migraine Disability Assessment (MIDAS) scores. We also summarised data on adverse events from placebo-controlled trials and calculated risk differences (RDs) and numbers needed to harm (NNHs).

MAIN RESULTS

Ten papers describing 10 unique trials met the inclusion criteria. Analysis of data from two trials (63 participants) showed that sodium valproate reduced headache frequency by approximately four headaches per 28 days as compared to placebo (MD -4.31; 95% confidence interval (CI) -8.32 to -0.30). Data from four trials (542 participants) showed that divalproex sodium (a stable combination of sodium valproate and valproic acid in a 1:1 molar ratio) more than doubled the proportion of responders relative to placebo (RR 2.18; 95% CI 1.28 to 3.72; NNT 4; 95% CI 2 to 11). One study of sodium valproate (34 participants) versus placebo supported the latter findings (RR for responders 2.83; 95% CI 1.27 to 6.31; NNT 3; 95% CI 2 to 9). There was no significant difference in the proportion of responders between sodium valproate versus flunarizine (one trial, 41 participants) or between divalproex sodium versus propranolol (one trial, 32 participants). Pooled analysis of post-treatment mean headache frequencies in two trials (88 participants) demonstrates a slight but significant advantage for topiramate 50 mg over valproate 400 mg (MD -0.90; 95% CI -1.58 to -0.22). For placebo-controlled trials of sodium valproate and divalproex sodium, NNHs for clinically important adverse events ranged from 7 to 14.

AUTHORS' CONCLUSIONS

Valproate is effective in reducing headache frequency and is reasonably well tolerated in adult patients with episodic migraine.

Migraine preventive drugs differentially affect cortical spreading depression in rat

Cortical spreading depression (CSD) is the most likely cause of the migraine aura. Drugs with distinct pharmacological properties are effective in the preventive treatment of migraine. To test the hypothesis that their common denominator might be suppression of CSD we studied in rats the effect of three drugs used in migraine prevention: lamotrigine which is selectively effective on the aura but not on the headache, valproate and riboflavin which have a non-selective effect. Rats received for 4 weeks daily intraperitoneal injections of one of the three drugs. For valproate and riboflavin we used saline as control, for lamotrigine its vehicle dimethyl sulfoxide. After treatment, cortical spreading depressions were elicited for 2h by occipital KCl application. We measured CSD frequency, its propagation between a posterior (parieto-occipital) and an anterior (frontal) electrode, and number of Fos-immunoreactive nuclei in frontal cortex. Lamotrigine suppressed CSDs by 37% and 60% at posterior and anterior electrodes. Valproate had no effect on posterior CSDs, but reduced anterior ones by 32% and slowed propagation velocity. Riboflavin had no significant effect at neither recording site. Frontal Fos expression was decreased after lamotrigine and valproate, but not after riboflavin. Serum levels of administered drugs were within the range of those usually effective in patients. Our study shows that preventive anti-migraine drugs have differential effects on CSD. Lamotrigine has a marked suppressive effect which correlates with its rather selective action on the migraine aura. Valproate and riboflavin have no effect on the triggering of CSD, although they are effective in migraine without aura. Taken together, these results are compatible with a causal role of CSD in migraine with aura, but not in migraine without aura.

Anticonvulsants in Migraine Prophylaxis: A Cochrane Review

Several trials have asserted that some anticonvulsant drugs seem to be useful for the prophylaxis of migraine, but systematic reviews are sparse. We independently searched PubMed, EMBASE and the Cochrane Central Register of Controlled Trials until 2005, as well as Headache and Cephalalgia through April 2006, for prospective, controlled trials of anticonvulsant drugs. Data were calculated and pooled across studies and expressed as standardized mean differences, odds ratios and numbers-needed-to-treat. Anticonvulsants, considered as a class, reduce migraine frequency by about 1.3 attacks per 28 days compared with placebo, and more than double the number of patients for whom migraine frequency is reduced by ≥50% relative to placebo. Sodium valproate/divalproex sodium and topiramate were better than placebo, whereas acetazolamide, clonazepam, lamotrigine and vigabatrin were not; gabapentin, in particular, needs further evaluation. Trials designed with sufficient power to compare different drugs are also necessary.

Effects of valproate on vestibular symptoms and electronystagmographic findings in migraine patients

OBJECTIVES

To investigate the effects of valproic acid on vestibular symptoms and electronystagmography (ENG) findings in patients with migraine-related vestibulopathy.

METHODS

Thirty-seven patients with migraine (13 with vertigo, 13 with dizziness, and 11 without vestibular symptoms) were included in the study. Slow-released valproic acid (500 mg/d) was given for 3 months. Frequency of headache and vestibular symptoms in the first, second, and third months of the therapy were recorded and compared with the pretreatment values. The ENG findings were also evaluated before and 2 months after the therapy.

RESULTS

We determined that prophylactic low-dose valproic acid decreased the frequency of headache and vestibular symptoms, although it does not cause any statistically meaningful change in ENG findings.

CONCLUSIONS

Valproate can be used satisfactorily for patients with migraine who have vestibular complaints. Ineffectiveness of valproic acid on ENG findings can be clarified by the permanent effect of migraine on the vestibular system.

Anticonvulsant drugs for migraine prophylaxis

BACKGROUND

Anticonvulsant drugs seem to be useful in clinical practice for the prophylaxis of migraine. This might be explained by a variety of actions of these drugs in the central nervous system that are probably relevant to the pathophysiology of migraine.

OBJECTIVES

To describe and assess the evidence from controlled trials on the efficacy and tolerability of anticonvulsants for preventing migraine attacks in adult patients with migraine.

SEARCH STRATEGY

We searched MEDLINE (from 1966 on) and the Cochrane Central Register of Controlled Trials (CENTRAL). Date of most recent search: April 2003. Additional information was gained from hand-searching specialist headache journals; correspondence with pharmaceutical companies, authors of reports, and experts in the field; and a wide variety of review articles and book chapters.

SELECTION CRITERIA

Studies were required to be prospective, controlled trials of self-administered drug treatments taken regularly to prevent the occurrence of migraine attacks and/or to reduce the intensity of those attacks.

DATA COLLECTION AND ANALYSIS

Studies were selected and data extracted by two independent reviewers. For migraine frequency data, standardized mean differences (SMDs) were calculated for individual studies and pooled across studies. For dichotomous data on significant reduction in migraine frequency, odds ratios (ORs) and numbers-needed-to-treat (NNTs) were similarly calculated. Adverse events were analyzed by calculating numbers-needed-to-harm (NNHs) for studies using similar agents.

MAIN RESULTS

Fifteen papers were included in the review. Of these, 14 reported trials comparing anticonvulsants with placebo, as follows: four trials of divalproex sodium, three trials of topiramate, two trials of sodium valproate, two trials of gabapentin, and one trial each of carbamazepine, clonazepam, and lamotrigine. One paper reported a trial of sodium valproate versus an active comparator, flunarizine, and one trial of divalproex sodium versus placebo included a comparison against propranolol, also an active comparator. Data from 2024 patients were considered. Analysis of data from eight trials (n = 841) demonstrates that anticonvulsants, considered as a class, reduce migraine frequency by about 1.4 attacks per 28 days as compared to placebo (SMD -0.60; 95% confidence interval [CI] -0.93 to -0.26). Data from 10 trials (n = 1341) show that anticonvulsants, considered as a class, also more than double the number of patients for whom migraine frequency is reduced by 50% or more, relative to placebo (OR 3.90; 95% CI 2.61 to 5.82; NNT 3.8; 95% CI 3.2 to 4.6). For seven trials of sodium valproate and divalproex sodium, NNHs for five clinically important adverse events ranged from 6.6 to 16.3. For the three trials of topiramate, NNHs for eight adverse events (100-mg dose) ranged from 2.4 to 32.9.

REVIEWERS' CONCLUSIONS

Anticonvulsants appear to be both effective in reducing migraine frequency and reasonably well tolerated. There is noticeable variation among individual agents, but there are insufficient data to know whether this is due to chance or variation in true efficacy. Neither clonazepam nor lamotrigine was superior to placebo (one trial each). Relatively few robust trials are available for agents other than sodium valproate/divalproex sodium. Two recently published and large trials of topiramate demonstrated reasonable efficacy, and one further trial of this agent is anticipated in the near future.

Migraine prophylactic medication usage patterns in The Netherlands

This study aims to investigate usage patterns of specific migraine prophylactic medications in ergotamine and triptan patients commencing this treatment for the first time during 1 January 1992 until 31 December 1998. Usage patterns of specific migraine prophylactic drugs were evaluated for each patient by accessing data from a large prescription database and were characterized as continued, switch or stop use during the patient observation period. Several patient and medication-related factors were explored in order to identify a possible relationship with the specific usage pattern defined. Approximately 75% of the study population (n = 729) had terminated (stop or switch) prophylactic treatment after 1 year. Age < 40 years (relative risk (RR) 1.9; 95% confidence interval (CI) 1.2-3.2) and the concomitant use of non-steroidal anti-inflammatory drugs (RR 3.2; 95% CI 1.2-5.5) or specific abortive migraine drugs resulted in a faster onset of treatment modification (switch). Overall, migraine prophylactic treatment is used for a relatively short period, probably attributable to the common limitations associated with migraine prophylaxis, such as poor compliance and/or limited therapeutic efficacy. Patterns of use can be influenced by a variety of factors, including age, type of prescriber and certain co-medication. Patient interview studies are required to clarify these issues further.

The role of anticonvulsants in preventive migraine therapy

The mainstay of migraine treatment is pharmacotherapy. There have been numerous medications used to prevent migraine headaches, including b-blockers, calcium-channel blockers, anticonvulsants, and nonsteroidal anti-inflammatory drugs. Sodium valproate is the only antiepileptic drug approved by the Food and Drug Administration for migraine prevention. Newer antiepileptics, including gabapentin and topiramate, are being evaluated for their role in preventive therapy. The mechanism of action of antiepileptics is not fully understood, but they all share a common role in enhancing gamma-aminobutyric acid-mediated inhibition. This article reviews the role of anticonvulsants in preventive migraine therapy.

Valproic acid toxicity: overview and management

Acute valproic acid intoxication is an increasing problem, accounting for more than 5000 calls to the American Association of Poison Control Centers in 2000. The purpose of this paper is to review the pharmacology and toxicology of valproic acid toxicity. Unlike earlier antiepileptic agents, valproic acid appears to function neither through sodium channel inhibition nor through direct gamma-aminobutyric acid agonism, but through an indirect increase in regional brain gamma-aminobutyric acid levels. Manifestations of acute valproic acid toxicity are myriad, and reflect both exaggerated therapeutic effect and impaired intermediary metabolism. Central nervous system depression is the most common finding noted in overdose, and may progress to coma and respiratory depression. Cerebral edema has also been observed. Although hepatotoxicity is rare in the acute overdose setting, pancreatitis and hyperammonemia have been reported. Metabolic and hematologic derangements have also been described. Management of acute valproic acid ingestion requires supportive care and close attention to the airway. The use of controversial adjunctive therapies, including extracorporeal drug elimination and L-carnitine supplementation, will be discussed.