Dihydroergotamine protects against ischemic stroke by modulating microglial/macrophage polarization and inhibiting inflammation in mice

OBJECTIVES

The search for drugs that can protect the brain tissue and reduce nerve damage in acute ischemic stroke has emerged as a research hotspot. We investigated the potential protective effects and mechanisms of action of dihydroergotamine against ischemic stroke.

METHODS

C57BL/6 mice were subjected to middle cerebral artery occlusion (MCAO), and dihydroergotamine at a dose of 10 mg/kg/day was intraperitoneally injected for 14 days. Adhesive removal and beam walking tests were conducted 1, 3, 5, 7, 10, and 14 days after MCAO surgery. Thereafter, the mechanism by which dihydroergotamine regulates microglia/macrophage polarization and inflammation and imparts ischemic stroke protection was studied using enzyme-linked immunosorbent assay, immunofluorescence staining, and western blotting.

RESULTS

From the perspective of a drug repurposing strategy, dihydroergotamine was found to inhibit oxygen-glucose deprivation damage to neurons, significantly improve cell survival rate, and likely exert a protective effect on ischemic brain injury. Dihydroergotamine significantly improved neural function scores and survival rates and reduced brain injury severity in mice. Furthermore, dihydroergotamine manifests its protective effect on ischemic brain injury by reducing the expression of TNF-α and IL-1β in mouse ischemic brain tissue, inhibiting the polarization of microglia/macrophage toward the M1 phenotype and promoting polarization toward the M2 phenotype.

CONCLUSION

This study is the first to demonstrate the protective effect of dihydroergotamine, a first-line treatment for migraine, against ischemic nerve injury in vitro and in vivo.

The 5-HT1B and 5-HT1D agonists in acute migraine therapy: Ergotamine, dihydroergotamine, and the triptans

The advent of the triptans revolutionized acute migraine treatment. The older migraine-specific drugs, the ergot alkaloids (ergotamine and dihydroergotamine), also relieve migraine attacks through agonism at the 5-HT1B and 5-HT1D receptors, but the triptans have much greater specificity for these receptors. Unlike the ergot alkaloids, the triptans do not activate many other receptor types, and therefore are much better tolerated. This reduction in side effects greatly enhanced their clinical utility as it allowed a far greater proportion of patients to take a full therapeutic dose. As a result, the clinical use of ergotamine is minimal today, although dihydroergotamine still has a significant clinical role. There is extensive evidence that the seven triptans available today, sumatriptan, zolmitriptan, rizatriptan, eletriptan, naratriptan, almotriptan, and frovatriptan, are effective in the acute treatment of migraine. Available formulations include oral tablets, orally dissolving tablets, subcutaneous injections, nasal sprays, and in some countries, rectal suppositories. For optimal benefit, therapy needs to be individualized for a given patient both regarding the triptan chosen and the formulation. This chapter discusses the ergot alkaloids and the triptans, including mechanism of action, evidence for efficacy, clinical use, and adverse effects.

Dihydroergotamine ameliorates liver fibrosis by targeting transforming growth factor β type II receptor

BACKGROUND

The transforming growth factor β (TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type II receptor (TGFβR2), followed by the recruitment of TGFβR1 finally triggering downstream signaling pathway.

AIM

To find drugs targeting TGFβR2 that inhibit TGFβR1/TGFβR2 complex formation, theoretically inhibit TGFβ signaling pathway, and thereby ameliorate liver fibrosis.

METHODS

Food and Drug Administration-approved drugs were screened for binding affinity with TGFβR2 by virtual molecular docking. We identified 6 candidates and further explored their potential by Cell Counting Kit-8 (CCK-8) cell cytotoxic experiment to validate toxicity and titrated the best cellular working concentrations. Next, we further demonstrated the detailed molecular working mechanisms using mutagenesis analysis. Finally, we used a mouse model to investigate its potential anti-liver fibrosis effect.

RESULTS

We identified 6 drug candidates. Among these 6 drugs, dihydroergotamine (DHE) shows great ability in reducing fibrotic gene expressions such as collagen, p-SMAD3, and α-SMA in TGFβ induced cellular model of liver fibrosis in LX-2 cells. Furthermore, we demonstrated that DHE binds to TGFβR2. Moreover, mutation of Leu27, Phe30, Thr51, Ser52, Ile53, and Glu55 of TGFβR2 disrupted the binding of TGFβR2 with DHE. In addition, DHE significantly improved liver fibrosis, as evidenced by Masson’s trichrome staining of liver sections. This is further supported by the width and the velocity of the portal vein, and serum markers of liver function. In line with those observations, DHE also decreased macrophages infiltration and extracellular matrix deposition in the liver.

CONCLUSION

DHE alleviates liver fibrosis by binding to TGFβR2 thereby suppressing TGFβ signaling pathway. We show here that as far as drug repurposing, DHE has great potential to treat liver fibrosis.

Observational Analysis of the Costs Associated with Acute Treatment of Breakthrough Migraine Attacks in Medicaid Patients Using Preventive Therapies

INTRODUCTION

Medications for preventive treatment of migraine reduce migraine frequency, usually measured by a reduction in monthly migraine days (MMD), but generally do not eliminate the need for acute treatment. To assess the economic impact of treatment-related reductions in frequency, methodological guidance recommends capturing cost differences along the spectrum of MMD.

OBJECTIVE

Characterize monthly migraine medication costs along the spectrum of MMD for patients using calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) for prevention.

METHODS

Medicaid State Drug Utilization Data (SDUD) were used to identify formulations and per-unit costs for oral, intranasal, and parenteral migraine-specific medications for acute and preventive treatment used by fee-for-service (FFS) Medicaid enrollees in 2020. National drug codes of relevant therapies were used to match SDUD to formulation characteristics including substance, route of administration, and branded/generic marketing status. Mean per-unit cost and the formulation's share of total prescriptions were estimated. Monthly medication costs were modeled based on formulations' per-unit costs and frequency of acute medication use during clinical trials of CGRP mAbs.

RESULTS

In the SDUD, there were 563,338 prescriptions for migraine-specific acute medications; triptans accounted for 97.37%. Triptan formulations prescribed were 83.78% oral tablet, 10.89% orally disintegrating tablet, 2.60% intranasal, and 2.73% parenteral. Dihydroergotamine accounted for < 1% of total prescriptions and had the highest per-unit cost ($443.50, branded intranasal). There were 97,119 prescriptions for CGRP mAbs, the majority for erenumab (45.73%) or galcanezumab (45.24%). Modeled monthly acute and preventive medication costs ranged from approximately $550 in patients with the fewest MMD treated with oral triptans to > $1500 in patients with the most MMD treated with dihydroergotamine.

CONCLUSION

In consideration of the migraine-specific acute medications used in FFS Medicaid 2020, for patients using CGRP mAbs for prevention, medication costs may vary significantly with the number of breakthrough attacks treated per month and the type of migraine-specific acute therapy used.

Peripheral Nerve Blocks: A Tool for Inpatient Pediatric Status Migrainosus

BACKGROUND

To assess the efficacy and safety of peripheral nerve blocks in the inpatient settings for pediatric patients presenting with status migrainosus.

METHODS

An analysis of a retrospective cohort of patients aged 13 to 18 years, admitted for status migrainosus from 2017 to 2022, was performed. Among the 1805 patients who presented with status migrainosus, 265 required hospital admission. A total of 177 patients failed the first- and second-line intravenous therapy and were treated with either peripheral nerve block (PNB) or dihydroergotamine (DHE) intravenous infusions. The primary outcome of the study was pain score level reduction by 50%, and the secondary outcome was duration of hospital stay. Visual analog scale score was used for pain assessment.

RESULTS

Among the 177 patients, 100 patients were treated with DHE and 77 were treated with PNB. Target pain control was achieved in 59 of 100 patients receiving DHE and 38 of 77 patients receiving PNB. The average hospital stay of patients who responded to PNB was significantly lower compared with that of patients receiving DHE (3.6 days vs 4.9 days). Among the 41 patients who were refractory to DHE, 30 patients received PNB, of which 12 responded to nerve blocks. The most common side effects for PNBs were pain at injection site in 39% of patients and nausea/vomiting for DHE in 50% of patients.

CONCLUSIONS

PNB can be safely administered in the hospital setting to pediatric patients with status migrainosus. PNB treatment helped achieve target pain control with minimal side effects and reduced the hospital stay duration.

Variability in recurrence rates with acute treatments for migraine: why recurrence is not an appropriate outcome measure

BACKGROUND

Headache recurrence is a common feature of acute therapies, whether approved or still in development, and continues to be a significant problem for both the patient and the clinician. Further complicating this issue is lack of standardization in definitions of recurrence used in clinical trials, as well as disparity in patient characteristics, rendering a comparison of different acute medications challenging. Recurrence has serious clinical implications, which can include an increased risk for new-onset chronic migraine and/or development of medication overuse headache. The aim of this review is to illustrate variability of recurrence rates depending on prevailing definitions in the literature for widely used acute treatments for migraine and to emphasize sustained response as a clinically relevant endpoint for measuring prolonged efficacy. BODY: A literature search of PubMed for articles of approved acute therapies for migraine that reported recurrence rates was performed. Study drugs of interest included select triptans, gepants, lasmiditan, and dihydroergotamine mesylate. An unpublished post hoc analysis of an investigational dihydroergotamine mesylate product that evaluated recurrence rates using several different definitions of recurrence common in the literature is also included. Depending on the criteria established by the clinical trial and the definition of recurrence used, rates of recurrence vary considerably across different acute therapies for migraine, making it difficult to compare results of different trials to assess the sustained (i.e., over a single attack) and the prolonged (i.e., over multiple attacks) efficacy of a particular study medication.

CONCLUSION

A standardized definition of recurrence is necessary to help physicians evaluate recurrence rates of different abortive agents for migraine. Sustained pain relief or freedom may be more comprehensive efficacy outcome measures than recurrence. Future efficacy studies should be encouraged to use the recommended definition of sustained pain freedom set by the International Headache Society.

Development and Evaluation of an Integrated Outpatient Infusion Care Model for the Treatment of Pediatric Headache

BACKGROUND

Care for pediatric patients with headache often occurs in high-cost settings such as emergency departments (EDs) and inpatient settings. Outpatient infusion centers have the potential to reduce care costs for pediatric headache management.

METHODS

In this quality improvement study, we describe our experience in creating the capacity to support an integrated outpatient pediatric headache infusion care model through an infusion center. We compare costs of receiving headache treatment in this model with those in the emergency and inpatient settings. Because dihydroergotamine (DHE) is a costly infusion, encounters at which DHE was administered were analyzed separately. We track the number of ED visits and inpatient admissions for headache using run charts. As a balancing measure, we compare treatment efficacy between the infusion care model and the inpatient setting.

RESULTS

The mean percentage increase in cost of receiving headache treatment in the inpatient setting with DHE was 61% (confidence interval [CI]: 30-99%), and that without DHE was 582% (CI: 299-1068%) compared with receiving equivalent treatments in the infusion center. The mean percentage increase in cost of receiving headache treatment in the ED was 30% (CI: -15 to 100%) compared with equivalent treatment in the infusion center. After the intervention, ED visits and inpatient admissions for headache decreased. The mean change in head pain was similar across care settings.

CONCLUSIONS

Our findings demonstrate that developing an integrated ambulatory care model with infusion capacity for refractory pediatric headache is feasible, and our early outcomes suggest this may have a favorable impact on the overall value of care for this population.

In silico screening of FDA approved drugs reveals ergotamine and dihydroergotamine as potential coronavirus main protease enzyme inhibitors

Coronaviruses with the largest viral genomes are positive-sense RNA viruses associated with a history of global epidemics such as the severe respiratory syndrome (SARS), the Middle East respiratory syndrome (MERS) and recently the coronavirus disease 2019 (COVID-19). There has been no vaccines or drugs available for the treatment of human coronavirus infections to date. In the present study, we have explored the possibilities of FDA approved drugs as potential inhibitors of the coronavirus main protease, a therapeutically important drug target playing a salient role in the maturation and processing of the viral polyproteins and are vital for viral replication and transcription. We have used molecular docking approach and have successfully identified the best lead molecules for each enzyme target. Interestingly, the anti-migraine drugs such as ergotamine and its derivative, dihydroergotamine were found to bind to all the three target enzymes within the Cys-His catalytic dyad cleft with lower binding energies as compared to the control inhibitors (α-ketoamide 13b, SG85 and GC813) and the molecules are held within the pocket through a good number of hydrogen bonds and hydrophobic interactions. Hence both these lead molecules can be further taken for wet-lab experimentation studies before repurposing them as anti-coronaviral drug candidates.

Dihydroergotamine inhibits the vasodepressor sensory CGRPergic outflow by prejunctional activation of α2-adrenoceptors and 5-HT1 receptors

BACKGROUND

Dihydroergotamine (DHE) is an antimigraine drug that produces cranial vasoconstriction and inhibits trigeminal CGRP release; furthermore, it inhibits the vasodepressor sensory CGRPergic outflow, but the receptors involved remain unknown. Prejunctional activation of α_2A/2C-adrenergic, serotonin 5-HT_1B/1F, or dopamine D₂-like receptors results in inhibition of this CGRPergic outflow. Since DHE displays affinity for these receptors, this study investigated the pharmacological profile of DHE-induced inhibition of the vasodepressor sensory CGRPergic outflow.

METHODS

Pithed rats were pretreated i.v. with hexamethonium (2 mg/kg·min) followed by continuous infusions of methoxamine (20 μg/kg·min) and DHE (3.1 μg/kg·min). Then, stimulus-response curves (spinal electrical stimulation; T₉-T₁₂) or dose-response curves (i.v. injections of α-CGRP) resulted in frequency-dependent or dose-dependent decreases in diastolic blood pressure.

RESULTS

DHE inhibited the vasodepressor responses to electrical stimulation (0.56-5.6 Hz), without affecting those to i.v. α-CGRP (0.1-1 μg/kg). This inhibition by DHE (not produced by the methoxamine infusions): (i) was abolished by pretreatment with the combination of the antagonists rauwolscine (α₂-adrenoceptor; 310 μg/kg) plus GR127935 (5-HT_1B/1D; 31 μg/kg); and (ii) remained unaffected after rauwolscine (310 μg/kg), GR127935 (31 μg/kg) or haloperidol (D₂-like; 310 μg/kg) given alone, or after the combination of rauwolscine plus haloperidol or GR127935 plus haloperidol at the aforementioned doses.

CONCLUSION

DHE-induced inhibition of the vasodepressor sensory CGRPergic outflow is mainly mediated by prejunctional rauwolscine-sensitive α₂-adrenoceptors and GR127935-sensitive 5-HT_1B/1D receptors, which correlate with α_2A/2C-adrenoceptors and 5-HT_1B receptors, respectively. These findings suggest that DHE-induced inhibition of the perivascular sensory CGRPergic outflow may facilitate DHE's vasoconstrictor properties resulting in an increased vascular resistance.

Dihydroergotamine Complicating Reversible Cerebral Vasoconstriction Syndrome in Status Migrainosus

Reversible cerebral vasoconstriction syndrome (RCVS) is a clinicoradiological syndrome that occurs due to dysfunction of cerebrovascular autoregulation. It is characterized by recurrent thunderclap headache from cerebral vasoconstriction which can cause ischemic infarction, spontaneous intraparenchymal and subarachnoid hemorrhage. This syndrome can be triggered by a variety of etiologies including medications, infectious, and inflammatory conditions. The diagnosis is often delayed due to unawareness among the health-care providers and delayed neuroimaging evidence of vasoconstriction with or without ischemic and/or hemorrhagic infarction. Status migrainosus is a prevalent condition requiring emergency room visits and inpatient admission. Thus, patients with RCVS can be easily misdiagnosed with migraine. We report a patient with RCVS misdiagnosed as status migrainosus with visual aura, treated with intravenous dihydroergotamine with worsening of cerebral vasoconstriction and lead to ischemic and hemorrhagic complications. We discuss this complication and provide guidance on differentiating between migraine and RCVS.

The role of α1- and α2-adrenoceptor subtypes in the vasopressor responses induced by dihydroergotamine in ritanserin-pretreated pithed rats

Background

Dihydroergotamine (DHE) is an acute antimigraine agent that displays affinity for dopamine D₂-like receptors, serotonin 5-HT_1/2 receptors and α₁/α₂-adrenoceptors. Since activation of vascular α₁/α₂-adrenoceptors results in systemic vasopressor responses, the purpose of this study was to investigate the specific role of α₁- and α₂-adrenoceptors mediating DHE-induced vasopressor responses using several antagonists for these receptors.

Methods

For this purpose, 135 male Wistar rats were pithed and divided into 35 control and 100 pretreated i.v. with ritanserin (100 μg/kg; to exclude the 5-HT₂ receptor-mediated systemic vasoconstriction). Then, the vasopressor responses to i.v. DHE (1–3100 μg/kg, given cumulatively) were determined after i.v. administration of some α₁/α₂-adrenoceptor antagonists.

Results

In control animals (without ritanserin pretreatment), the vasopressor responses to DHE were: (i) unaffected after prazosin (α₁; 30 μg/kg); (ii) slightly, but significantly, blocked after rauwolscine (α₂; 300 μg/kg); and (iii) markedly blocked after prazosin (30 μg/kg) plus rauwolscine (300 μg/kg). In contrast, after pretreatment with ritanserin, the vasopressor responses to DHE were: (i) attenuated after prazosin (α₁; 10 and 30 μg/kg) or rauwolscine (α₂; 100 and 300 μg/kg); (ii) markedly blocked after prazosin (30 μg/kg) plus rauwolscine (300 μg/kg); (iii) attenuated after 5-methylurapidil (α_1A; 30–100 μg/kg), L-765,314 (α_1B; 100 μg/kg), BMY 7378 (α_1D; 30–100 μg/kg), BRL44408 (α_2A; 100–300 μg/kg), imiloxan (α_2B; 1000–3000 μg/kg) or JP-1302 (α_2C; 1000 μg/kg); and (iv) unaffected after the corresponding vehicles (1 ml/kg).

Conclusion

These results suggest that the DHE-induced vasopressor responses in ritanserin-pretreated pithed rats are mediated by α₁- (probably α_1A, α_1B and α_1D) and α₂- (probably α_2A, α_2B and α_2C) adrenoceptors. These findings could shed light on the pharmacological profile of the vascular side effects (i.e. systemic vasoconstriction) produced by DHE and may lead to the development of more selective antimigraine drugs devoid vascular side effects.