Clinical pharmacology of topiramate in migraine prevention

Evidence-based guidelines for the pharmacological treatment of migraine

We here present evidence-based guidelines for the pharmacological treatment of migraine. These guidelines, created by the Italian Society for the Study of Headache and the International Headache Society, aim to offer clear, actionable recommendations to healthcare professionals. They incorporate evidence-based recommendations from randomized controlled trials and expert-based opinions. The guidelines follow the Grading of Recommendations, Assessment, Development and Evaluation approach for assessing the quality of evidence. The guideline development involved a systematic review of literature across multiple databases, adherence to Cochrane review methods, and a structured framework for data extraction and interpretation. Although the guidelines provide a robust foundation for migraine treatment, they also highlight gaps in current research, such as the paucity of head-to-head drug comparisons and the need for long-term outcome studies. These guidelines serve as a resource to standardize migraine treatment and promote high-quality care across different healthcare settings.

Antiseizure Medications for the Prophylaxis of Migraine during the Anti- CGRP Drugs Era

Migraine and epilepsy are fundamentally distinct disorders that can frequently coexist in the same patient. These two conditions significantly differ in diagnosis and therapy but share some widely- used preventive treatments. Antiseizure medications (ASMs) are the mainstay of therapy for epilepsy, and about thirty different ASMs are available to date. ASMs are widely prescribed for other neurological and non-neurological conditions, including migraine. However, only topiramate and valproic acid/valproate currently have an indication for migraine prophylaxis supported by high-quality evidence. Although without specifically approved indications and with a low level of evidence or recommendation, several other ASMs are used for migraine prophylaxis. Understanding ASM antimigraine mechanisms, including their ability to affect the pro-migraine calcitonin gene-related peptide (CGRP) signaling pathway and other pathways, may be instrumental in identifying the specific targets of their antimigraine efficacy and may increase awareness of the neurobiological differences between epilepsy and migraine. Several new ASMs are under clinical testing or have been approved for epilepsy in recent years, providing novel potential drugs for migraine prevention to enrich the treatment armamentarium and drugs that inhibit the CGRP pathway.

Migraine and Neuroticism: A Scoping Review

Headache is the first cause of consultation in neurology, and one of the most frequent reasons for consultation in general medicine. Migraine is one of the most common, prevalent, and socioeconomically impactful disabling primary headache disorders. Neuroticism can be conceptualized as a disposition to suffer anxiety and emotional disorders in general. Neuroticism has been associated with various mental and physical disorders (e.g., chronic pain, depression), including migraine. With the aim to explore in depth the relationship between migraine and neuroticism, and contribute to the understanding of this relation in order to provide a better treatment for migraine patients based on a personalized and more comprehensive approach, a scoping review was performed using PubMed, Scopus, and Web of Science. Databases were searched independently by the two researchers, reaching a final set of 18 articles to be included. The search terms were: migraine and neuroticism. Neuroticism seems to be highly prevalent in migraine patients. Findings reveal that migraine patients with comorbid depression and anxiety showed higher levels of neuroticism. Depression has been associated with an increased risk of transformation from episodic to chronic migraine whereas neuroticism might be a mediator factor. Neuroticism also might be a mediator factor between childhood maltreatment and migraine. The revision conducted confirms that: (1) Migraine patients usually have a higher level of neuroticism and vulnerability to negative affect, compared to non-migraineurs and tension-type headache patients. (2) Neuroticism is associated with migraine. Nonetheless, more research is needed to clarify potential moderators of this relationship and the role of neuroticism itself in this disease. This knowledge might be useful in order to promote a better management of negative emotions as part of intervention programs in migraine.

Synthesis and Human Carbonic Anhydrase I, II, IX, and XII Inhibition Studies of Sulphonamides Incorporating Mono-, Bi- and Tricyclic Imide Moieties

New derivatives were synthesised by reaction of amino-containing aromatic sulphonamides with mono-, bi-, and tricyclic anhydrides. These sulphonamides were investigated as human carbonic anhydrases (hCAs, EC 4.2.1.1) I, II, IX, and XII inhibitors. hCA I was inhibited with inhibition constants (Kis) ranging from 49 to >10,000 nM. The physiologically dominant hCA II was significantly inhibited by most of the sulphonamide with the Kis ranging between 2.4 and 4515 nM. hCA IX and hCA XII were inhibited by these sulphonamides in the range of 9.7 to 7766 nM and 14 to 316 nM, respectively. The structure-activity relationships (SAR) are rationalised with the help of molecular docking studies.

Topiramate: Comprehensive profile

Topiramate, 2,3:4,5-di-O-isopropylidene-β-d-fructopyranose sulfamate, is a potent antiepileptic drug with a broad spectrum of activity. It is effective in both partial and generalized seizures. Topiramate was also found to have significant efficacy in migraine prevention with considerable reductions in the frequency of migraine headaches. The most common adverse events, which may accompany the use of topiramate, are paresthesia, fatigue, decreased appetite, nausea, diarrhea, weight decrease and taste perversion. The weight loss observed with the use of topiramate in obese, epileptic patients, afforded the approval of this drug as an anti-obesity medication. This action is thought to be based on the selective inhibition of mitochondrial carbonic anhydrase isoforms. This profile is prepared to discuss and explain physical characteristics, proprietary and nonproprietary names of topiramate. It also includes methods of preparation, thermal and spectral behavior and methods of analysis. Pharmacokinetics, metabolism, excretion and pharmacology together with its uses and applications are also discussed.

Drug-induced retroperitoneal fibrosis: short aetiopathogenetic note, from the past times of ergot-derivatives large use to currently applied bio-pharmacology

Among the secondary forms of retroperitoneal fibrosis (RPF), that drug-induced shows very intriguing aspects given both the broad range of involved pharmaceuticals and the considerable interest arisen from the related pathogenetic mechanisms. The particular incidence, in the last four decades past century, of the RPF due to long-term use of ergot alkaloid derivatives (ergotamine, methysergide, pergolide, bromocriptine, cabergoline) and specific L-dopa derived agents, such as methyldopa, as well as to different analgesics, came progressively down given that their long-term use for either the prevention of migraine attacks or the therapy of chronic pathologies (Parkinson's disease, prolactinoma, pain management, etc) has been, year after year, supplanted or even made unavailable in many countries. More recently, instead, the occurrence of the RPF has been sometimes identified with the use of antitumoral chemotherapeutics, such as carboplatin and methotrexate, and, just lately, as an unusual side-effect of certain biological agents, about which it is timely to go into specific pathogenetic problems in more depth.

Long-lasting recognition memory impairment and alterations in brain levels of cytokines and BDNF induced by maternal deprivation: effects of valproic acid and topiramate

Exposure to stressful events early in life may have permanent deleterious consequences on nervous system function and increase the susceptibility to psychiatric conditions later in life. Maternal deprivation, commonly used as a source of neonatal stress, impairs memory in adult rats and reduces hippocampal brain-derived neurotrophic factor (BDNF) levels. Inflammatory cytokines, such as interleukins (IL) and tumor necrosis factor-α (TNF-α) have been shown to be increased in the peripheral blood of patients with psychiatric disorders. The aim of the present study was to investigate the effects of maternal separation on the levels of IL-10 and TNF-α, and BDNF in the hippocampus and prefrontal cortex of adult rats. We also evaluated the potential ameliorating properties of topiramate and valproic acid on memory deficits and cytokine and BDNF changes associated with maternal deprivation. The results indicated that, in addition to inducing memory deficits, maternal deprivation increased the levels of IL-10 in the hippocampus, and TNF-α in the hippocampus and in the cortex, and decreased hippocampal levels of BDNF, in adult life. Neither valproic acid nor topiramate were able to ameliorate memory deficits or the reduction in BDNF induced by maternal separation. The highest dose of topiramate was able to reduce IL-10 in the hippocampus and TNF-α in the prefrontal cortex, while valproate only reduced IL-10 levels in the hippocampus. These findings may have implications for a better understanding of the mechanisms associated with alterations observed in adult life induced by early stressful events, and for the proposal of novel therapeutic strategies.

Evaluating the Phase II drugs currently under investigation for diabetic neuropathy

Introduction: The worldwide number of patients suffering from diabetes mellitus (DM) is projected to approach 552 million by the year 2030. As diabetic neuropathy (DN) is present in 8% of new diabetic patients at the time of diagnosis and occurs in ∼ 50% of all patients with established DM, the number of patients who will develop painful DN will also increase. The suboptimal efficacies of currently approved drugs have prompted investigators to develop new therapeutic agents for the management of painful DN. Areas covered: In this review, the authors present and elucidate the current status of drugs under investigation for the treatment of painful DN. A short synopsis of currently approved drugs is also given. Literature information and data analysis were retrieved from PubMed, the American Diabetes and Neurological Associations Websites and ClinicalTrials.gov. The keywords used in the search included: DM, DN, painful diabetic neuropathy. Expert opinion: In addition to treating the pain associated with DN, the actual causes of the disease should also be targeted for improved management. It is hoped that drugs which improve vascular blood flow, induce neural regeneration, reduce hyperglycemia, oxidative stress and inflammation can be more effective for the overall treatment of painful DN.

The insulin sensitizing effect of topiramate involves KATP channel activation in the central nervous system

BACKGROUND AND PURPOSE

Topiramate improves insulin sensitivity, in addition to its antiepileptic action. However, the underlying mechanism is unknown. Therefore, the present study was aimed at investigating the mechanism of the insulin-sensitizing effect of topiramate both in vivo and in vitro.

EXPERIMENTAL APPROACH

Male C57Bl/6J mice were fed a run-in high-fat diet for 6 weeks, before receiving topiramate or vehicle mixed in high-fat diet for an additional 6 weeks. Insulin sensitivity was assessed by hyperinsulinaemic-euglycaemic clamp. The extent to which the insulin sensitizing effects of topiramate were mediated through the CNS were determined by concomitant i.c.v. infusion of vehicle or tolbutamide, an inhibitor of ATP-sensitive potassium channels in neurons. The direct effects of topiramate on insulin signalling and glucose uptake were assessed in vivo and in cultured muscle cells.

KEY RESULTS

In hyperinsulinaemic-euglycaemic clamp conditions, therapeutic plasma concentrations of topiramate (∼4 μg·mL(-1) ) improved insulin sensitivity (glucose infusion rate + 58%). Using 2-deoxy-D-[(3) H]glucose, we established that topiramate improved the insulin-mediated glucose uptake by heart (+92%), muscle (+116%) and adipose tissue (+586%). Upon i.c.v. tolbutamide, the insulin-sensitizing effect of topiramate was completely abrogated. Topiramate did not directly affect glucose uptake or insulin signalling neither in vivo nor in cultured muscle cells.

CONCLUSION AND IMPLICATIONS

In conclusion, topiramate stimulates insulin-mediated glucose uptake in vivo through the CNS. These observations illustrate the possibility of pharmacological modulation of peripheral insulin resistance through a target in the CNS.