Emergent management of primary headache: a review of current literature

Acute Pain and Development of Opioid Use Disorder: Patient Risk Factors

PURPOSE OF REVIEW

Pharmacological therapy for acute pain carries the risk of opioid misuse, with opioid use disorder (OUD) reaching epidemic proportions worldwide in recent years. This narrative review covers the latest research on patient risk factors for opioid misuse in the treatment of acute pain. In particular, we emphasize newer findings and evidence-based strategies to reduce the prevalence of OUD.

RECENT FINDINGS

This narrative review captures a subset of recent advances in the field targeting the literature on patients' risk factors for OUD in the treatment for acute pain. Besides well-recognized risk factors such as younger age, male sex, lower socioeconomic status, White race, psychiatric comorbidities, and prior substance use, additional challenges such as COVID-19 further aggravated the opioid crisis due to associated stress, unemployment, loneliness, or depression. To reduce OUD, providers should evaluate both the individual patient's risk factors and preferences for adequate timing and dosing of opioid prescriptions. Short-term prescription should be considered and patients at-risk closely monitored. The integration of non-opioid analgesics and regional anesthesia to create multimodal, personalized analgesic plans is important. In the management of acute pain, routine prescription of long-acting opioids should be avoided, with implementation of a close monitoring and cessation plan.

Narrative Review: Low-Dose Ketamine for Pain Management

Pain is the leading cause of medical consultations and occurs in 50-70% of emergency department visits. To date, several drugs have been used to manage pain. The clinical use of ketamine began in the 1960s and it immediately emerged as a manageable and safe drug for sedation and anesthesia. The analgesic properties of this drug were first reported shortly after its use; however, its psychomimetic effects have limited its use in emergency departments. Owing to the misuse and abuse of opioids in some countries worldwide, ketamine has become a versatile tool for sedation and analgesia. In this narrative review, ketamine's role as an analgesic is discussed, with both known and new applications in various contexts (acute, chronic, and neuropathic pain), along with its strengths and weaknesses, especially in terms of psychomimetic, cardiovascular, and hepatic effects. Moreover, new scientific evidence has been reviewed on the use of additional drugs with ketamine, such as magnesium infusion for improving analgesia and clonidine for treating psychomimetic symptoms. Finally, this narrative review was refined by the experience of the Pain Group of the Italian Society of Emergency Medicine (SIMEU) in treating acute and chronic pain with acute manifestations in Italian Emergency Departments.

The NMDA receptor antagonists memantine and ketamine as anti-migraine agents

Migraine is a debilitating disorder affecting females more frequently than males. There is some evidence that drugs targeting glutamate receptors: memantine and ketamine might be beneficial in the therapy of this entity. Therefore, the purpose of this work is to present NMDA receptor antagonists, memantine and ketamine, as potential anti-migraine agents. We searched PubMed/MEDLINE, Embase, and clinical trials submitted to ClinicalTrials.gov to find publications describing eligible trials published between database inception and December 31, 2021. This comprehensive literature review summarizes data on the use of the NMDA receptor antagonists memantine and ketamine in the pharmacotherapy of migraine. Results from 20 previous and recent preclinical experiments are discussed and correlated with 19 clinical trials (including case series, open-label, and randomized placebo-controlled trials). For the purposes of this review, the authors hypothesized that the propagation of SD is a major mechanism in the pathophysiology of migraine. In several animal studies and in vitro studies, memantine and ketamine inhibited or reduced propagation of the SD. In addition, the results of clinical trials suggest that memantine or ketamine may be an effective treatment option for migraine. However, most studies on these agents lack control group. Although further clinical trials are needed, the results suggest that ketamine or memantine may be promising molecules for the treatment of severe migraine. Particular attention should be paid to people who have a treatment-resistant form of migraine with aura or have exhausted existing treatment options. For them, the drugs under discussion could represent an interesting alternative in the future.

Involvement of the NO/cGMP/K ATP pathway in the antinociceptive effect of rosemary ( Rosmarinus officinalis ) essential oil in mice

Rosemary essential oil (REO) has been used for several medical purposes. Previous studies have shown the antinociceptive effect of the oil. This study aimed to investigate the role of some well-known receptors in the antinociceptive effect of REO. Male Swiss mice (25-30 g) were used. To assess the antinociceptive activity, the formalin test was used. At first, the antinociceptive effect of three doses of rosemary oil (150, 300 and 450 µL/kg) was tested, and then a dose of 300 µL/kg was selected for the mechanistic study. Animals were pretreated with several antagonists and enzyme inhibitors to evaluate the role of adrenergic, cholinergic, serotoninergic, dopaminergic and opioid receptors as well as the NO/cGMP/K ATP pathway in the antinociceptive effect of rosemary essential oil. Yohimbine (5 mg/kg), prazocin (2 mg/kg), propranolol (2 mg/kg), atropine (2.5 mg/kg) naloxone (5 mg/kg), cyproheptadine (2 mg/kg), ondansetron (2 mg/kg) and haloperidol (1 mg/kg) could not reverse the antinociceptive effect. Sulpiride (20 mg/kg) only showed preventive activity in the early phase of formalin test while methylene blue (5 mg/kg), L-NAME (20 mg/kg) and glibenclamide (10 mg/kg) significantly attenuated the antinociceptive effect of REO in both phases. Tadalafil (2 mg/kg) potentiated the antinociceptive effect of REO in the late phase of formalin test and arginine (100 mg/kg) had no effect on both phases. Therefore the NO/cGMP/K ATP pathway might have an important role in the antinociceptive effect of REO.

Beyond the Raskin Protocol: Ketamine, Lidocaine, and Other Therapies for Refractory Chronic Migraine

PURPOSE OF REVIEW

The purpose of this review is to discuss the available evidence and therapeutic considerations for intravenous drug therapy for refractory chronic migraine.

RECENT FINDINGS

In carefully monitored settings, the inpatient administration of intravenous lidocaine and ketamine can be successful in treating refractory chronic migraine. Many patients with refractory chronic migraine have experienced treatment failure with the Raskin protocol. The use of aggressive inpatient infusion therapy consisting of intravenous lidocaine or ketamine, along with other adjunctive medications, has become increasingly common for these patients when all other treatments have failed. There is a clear need for prospective studies in this population comprised of patients who have largely been excluded from other studies.

Tapping into 5-HT3 Receptors to Modify Metabolic and Immune Responses

5-hydroxytryptamine type 3 (5-HT₃) receptors are ligand gated ion channels, which clearly distinguish their mode of action from the other G-protein coupled 5-HT or serotonin receptors. 5-HT₃ receptors are well established targets for emesis and gastrointestinal mobility and are used as adjunct targets in treating schizophrenia. However, the distribution of these receptors is wider than the nervous system and there is potential that these additional sites can be targeted to modulate inflammatory and/or metabolic conditions. Recent progress in structural biology and pharmacology of 5-HT₃ receptors have provided profound insights into mechanisms of their action. These advances, combined with insights into clinical relevance of mutations in genes encoding 5-HT₃ subunits and increasing understanding of their implications in patient's predisposition to diseases and response to the treatment, open new avenues for personalized precision medicine. In this review, we recap on the current status of 5-HT₃ receptor-based therapies using a biochemical and physiological perspective. We assess the potential for targeting 5-HT₃ receptors in conditions involving metabolic or inflammatory disorders based on recent findings, underscoring the challenges and limitations of this approach.

Efficacy of ketamine in the treatment of migraines and other unspecified primary headache disorders compared to placebo and other interventions: a systematic review

BACKGROUND

Migraine headaches are the second leading cause of disability worldwide and are responsible for significant morbidity, reduction in the quality of life, and loss of productivity on a global scale. The purpose of this systematic review and meta-analysis was to evaluate the efficacy of ketamine on migraines and other primary headache disorders compared to placebo and other active interventions, such as midazolam, metoclopramide/diphenhydramine, and prochlorperazine/diphenhydramine.

METHODS

An electronic search of databases published up to February 2021, including Medline via PubMed, EMBASE, Web of Science, and Cochrane Library, a hand search of the bibliographies of the included studies, as well as literature and systematic reviews found through the search was conducted to identify randomized controlled trials (RCTs) investigating ketamine in the treatment of migraine/headache disorders compared to the placebo. The authors assessed the risk of bias according to the Cochrane Handbook guidelines.

RESULTS

The initial search strategy yielded 398 unduplicated references, which were independently assessed by three review authors. After evaluation, this number was reduced to five RCTs (two unclear risk of bias and three high risk of bias). The total number of patients in all the studies was 193. Due to the high risk of bias, small sample size, heterogeneity of the outcomes reported, and heterogeneity of the comparison groups, the quality of the evidence was very low. One RCT reported that intranasal ketamine was superior to intranasal midazolam in improving the aura attack severity, but not duration, while another reported that intranasal ketamine was not superior to metoclopramide and diphenhydramine in reducing the headache severity. In one trial, subcutaneous ketamine was superior to saline in migraine severity reduction; however, intravenous (I.V.) ketamine was inferior to I.V. prochlorperazine and diphenhydramine in another study.

CONCLUSION

Further double-blind controlled studies are needed to assess the efficacy of ketamine in treating acute and chronic refractory migraines and other primary headaches using intranasal and subcutaneous routes. These studies should include a long-term follow-up and different ketamine dosages in diagnosed patients following international standards for diagnosing headache/migraine.

Optimal management strategies for primary headache in the emergency department

PURPOSE

We sought to evaluate the factors associated with better outcomes for emergency department (ED) patients treated for primary headache.

METHODS

This was a health records review of consecutive patients over a 3-month period presenting to two tertiary EDs and discharged with a diagnosis of primary headache. The primary outcome was the need for second round medications, defined as medications received > 1 h after the initial physician-ordered medications were administered. We performed multivariate logistic regression analysis to determine treatment factors associated with need for second round medications.

RESULTS

We included 553 patients, mean age was 42.2 years and 72.9% were females. The most common diagnoses were headache not otherwise specified (48.8%) and migraine (43%). Ketorolac IV (62.2%) and metoclopramide IV (70.2%) were the most frequently administered medications. 18% of patients met the primary outcome. Dopamine antagonists (OR 0.3 [95% CI 0.1-0.5]) and non-steroidal anti-inflammatory drugs (NSAIDs) (OR 0.5 [95% CI 0.3-0.8]) ordered with initial medications were associated with reduced need for second round medications. Intravenous fluid boluses ≥ 500 ml (OR 2.8 [95% CI: 1.5-5.2]) and non-dopamine antagonist antiemetics (OR 2.2 [95% CI 1.2-4.2]) were associated with increased need. Opioid use approached statistical significance for receiving second round medication (p = 0.06).

CONCLUSION

We determined that use of dopamine antagonists and NSAIDs were associated with a reduced need for second round medications in ED primary headache patients. Conversely, non-dopamine antagonist antiemetic medications and intravenous fluids were associated with a significantly increased need for second round medications. Careful choice of initial therapy may optimize management for these patients.

Diagnosis and Management of Headaches in the Emergency Department (ED) in Adults and Children

Background

Headache accounts for a significant number of cases presenting to the Emergency Department (ED) and has a high societal cost, contributed by recurrent ED and clinic visits, and unnecessary diagnostic tests.

Objective

This review article covers the important clinical tools needed to evaluate headaches in both adults and children in the ED.

Methods

Medline/PubMed was searched using the keywords "Emergency department", "headache", "adult", "pediatric", "clinical assessment", "diagnosis" and "treatment", in the title or abstract. The search covers the period from 1 January 1990 to 31 December 2019.

Results

The articles selected were based on their relevancy to the objective of this review article. Additional relevant publications were identified from article references lists.

Conclusion

The emergency physician plays a key role in differentiating between primary and secondary headaches. Within the limited ED resources, appropriate diagnostic testing should be used to identify the life-threatening headaches. This will ensure patients are given the appropriate evidence-based pharmacological therapy and holistic management.

A Review of Nonanesthetic Uses of Ketamine

Ketamine, a nonselective NMDA receptor antagonist, is used widely in medicine as an anesthetic agent. However, ketamine's mechanisms of action lead to widespread physiological effects, some of which are now coming to the forefront of research for the treatment of diverse medical disorders. This paper aims at reviewing recent data on key nonanesthetic uses of ketamine in the current literature. MEDLINE, CINAHL, and Google Scholar databases were queried to find articles related to ketamine in the treatment of depression, pain syndromes including acute pain, chronic pain, and headache, neurologic applications including neuroprotection and seizures, and alcohol and substance use disorders. It can be concluded that ketamine has a potential role in the treatment of all of these conditions. However, research in this area is still in its early stages, and larger studies are required to evaluate ketamine's efficacy for nonanesthetic purposes in the general population.

Acute headache management in emergency department. A narrative review

Headache is a significant reason for access to Emergency Departments (ED) worldwide. Though primary forms represent the vast majority, the life-threatening potential of secondary forms, such as subarachnoid hemorrage or meningitis, makes it imperative for the ED physician to rule out secondary headaches as first step, based on clinical history, careful physical (especially neurological) examination and, if appropriate, hematochemical analyses, neuroimaging or lumbar puncture. Once secondary forms are excluded, distinction among primary forms should be performed, based on the international headache classification criteria. Most frequent primary forms motivating ED observation are acute migraine attacks, particularly status migrainous, and cluster headache. Though universally accepted guidelines do not exist for headache management in an emergency setting, pharmacological parenteral treatment remains the principal approach worldwide, with NSAIDs, neuroleptic antinauseants, triptans and corticosteroids, tailored to the specific headache type. Opioids should be avoided, for their scarce effectiveness in the acute phase, while IV hydration should be limited in cases of ascertained dehydration. Referral of the patient to a Headache Center should subsequently be an integral part of the ED approach to the headache patients, being ascertained that lack of this referral involves a high rate of relapse and new accesses to the ED. More controlled studies are needed to establish specific protocols of management for the headache patient in the ED.