A narrative review of the importance of pharmacokinetics and drug-drug interactions of preventive therapies in migraine management.

OBJECTIVE: To review the pharmacokinetics of major classes of migraine preventives and the clinical implications of drug-drug interactions (DDIs) with the use of these therapies in migraine management. BACKGROUND: Preventive treatments for migraine are recommended for a large proportion of patients with frequent migraine attacks. These patients often exhibit a number of comorbidities, which may lead to the introduction of multiple concomitant therapies. Potential DDIs must be considered when using polytherapy to avoid increased risk of adverse events (AEs) or inadequate treatment of comorbid conditions. METHODS: A literature search was performed to identify pharmacokinetic properties and potential DDIs of beta-blockers, antiepileptic drugs, antidepressants, calcium channel blockers, gepants, and monoclonal antibody therapies targeting the calcitonin gene-related peptide pathway with medications that may be used for comorbid conditions. RESULTS: Most DDIs occur through alterations in cytochrome P450 isoenzyme activity and may be complicated by genetic polymorphism for metabolic enzymes. Additionally, drug metabolism may be altered by grapefruit juice ingestion and smoking. The use of migraine preventive therapies may exacerbate symptoms of comorbid conditions or increase the risk of AEs associated with comorbid conditions as a result of DDIs. CONCLUSIONS: DDIs are important to consider in patients with migraine who use multiple medications. The development of migraine-specific evidence-based preventive treatments allows for tailored clinical management that reduces the risk of DDIs and associated AEs in patients with comorbidities.

Real-World Treatment Profiles, Clinical Outcomes, and Healthcare Resource Utilization of Patients with Migraine Prescribed Erenumab: A Multicenter Chart-Review Study of US Headache Centers.

INTRODUCTION: Erenumab, a first-in-class monoclonal antibody targeting the calcitonin gene-related peptide pathway, was approved by the US Food and Drug Administration in 2018 for the prevention of migraine in adults. There is limited data available on its impact in real-world settings. The study aim was to characterize the real-world treatment profiles, clinical outcomes, and healthcare resource utilization of patients prescribed erenumab from select major US headache centers. METHODS: A retrospective chart review of patients with migraine treated with erenumab for at least 3 months across five major headache centers was conducted. Data was collected from patient charts between April 2019 and April 2020 and included patient and clinical characteristics, migraine medication use, and outpatient visits. The date of the first prescription fill of erenumab was defined as the index date. The baseline period comprised the 3 months prior to the index date and the study period comprised the at least 3 months on erenumab treatment. RESULTS: Data from a total of 1034 patients with chronic migraine with a mean of 9.3 months of erenumab treatment were analyzed. Patients were on average 48 years old, 86% were female, and 79% were white. Patients had a mean of 5 preventive treatment failures prior to erenumab initiation. Patients used a mean of 2 preventive treatments (excluding erenumab) and 2 acute treatments during baseline and study periods. Among patients with effectiveness data, 45% of patients had improvement in physician-reported migraine severity and 35% experienced at least 50% reduction in mean headache/migraine days per month. The average number of monthly outpatient visits was 0.43 and 0.30 before and after erenumab initiation, respectively. CONCLUSION: In this predominantly refractory chronic migraine population treated in select headache centers, patients had fewer headache/migraine days per month and outpatient visits after initiating erenumab. However, patients largely continued to be managed via a polypharmacy approach after erenumab initiation.

Peptides, MAbs, Molecules, Mechanisms, and More: Taking a Stab at Cluster Headache.

BACKGROUND: Cluster headache is a highly disabling neurological disorder. PURPOSE: The purpose of this review is to highlight recent therapeutic advances in the treatment of cluster headache such as monoclonal antibodies as well as non-invasive vagus nerve stimulation, and examine future potential therapeutic targets. DISCUSSION: Several therapeutic agents currently in use may have underlying mechanisms important to cluster headache pathophysiology and have yet to be completely elucidated. The psychobiological aspects of cluster headache have a significant impact on patients, as well as pose limitations for treatment. Neuropeptides may play a role in underlying mechanisms in why cluster headache patients are frequent tobacco smokers. Alterations in the hypothalamic-pituitary-adrenal axis and neuroinflammation may play a role in suicidality. The circadian nature of cluster headache may generate the development of future treatment options. New understanding of mechanisms underlying post-traumatic headache may also provide insights into cluster headache pathophysiology. CONCLUSION: Molecular targets and neuromodulation advances have paved the way for a new generation of therapeutic agents in cluster headache. There are several other potential targets.

The comorbidity burden of patients with cluster headache: a population-based study.

BACKGROUND: Evidence is limited regarding the comorbidity burden of patients with cluster headache (CH). We aimed to characterize comorbid conditions in a cohort of CH patients diagnosed by headache experts, using electronic health record information from the Partners Research Patient Data Registry (RPDR). METHODS: We identified and reviewed the charts of unique patients diagnosed by headache specialists over an 11-year period, and a set of matched controls. Patients were categorized as having Definite, Unconfirmed or no CH. We calculated the prevalence of and tested for statistically significant differences of selected comorbid conditions in these populations. RESULTS: An RPDR query identified 170 patients with a free text or ICD diagnosis of cluster headache. 15 records belonging to Partners employees were excluded. 75 patients met diagnostic criteria for CH (Definite CH). 22 had headaches with some features of CH but the diagnosis was uncertain (Unconfirmed CH). In 58 the diagnosis was determined to be inaccurate due to data entry errors. Patients with Definite CH had an average age of 43.4 years; 80% were male. The average time from CH onset to diagnosis was 12.7 years (range 1-51). The average number of yearly emergency department and outpatient visits for the group of Definite CH patients was 4.5 and 25.4, respectively, compared with 1.1 and 6.9 in controls. Of the 55 examined conditions, four were statistically significantly less common in patients with definite CH compared with controls (diabetes, musculoskeletal/orthopaedic problems, "other gastrointestinal diagnoses" and skin conditions) and four were statistically significantly more common (smoking, depression, dental disorders and deviated septum). CONCLUSIONS: In this large population-based study, we identified a surprisingly small number of patients who met strict diagnostic criteria for CH. In these patients, however, we identified a distinct pattern of selected comorbidities. The pattern is somewhat but not entirely consistent with that of the "classic" CH patient depicted in the medical literature. CH patients are frequently diagnosed with sinus or dental problems. Many experience substantial delay in receiving a diagnosis. These things may in part explain the high frequency of medical visits in this population. It is difficult to distinguish conditions that are genuinely comorbid with CH from those that reflect misdiagnoses or medical scrutiny of patients in frequent contact with the healthcare system.

Clinical Characteristics and Treatment Patterns Among Patients Diagnosed With Cluster Headache in U.S. Healthcare Claims Data.

OBJECTIVE: To characterize demographics, clinical characteristics, and treatment patterns of patients with cluster headache (CH). BACKGROUND: CH is an uncommon trigeminal autonomic cephalalgia with limited evidence-based treatment options. Patients suffer from extremely painful unilateral headache attacks and autonomic symptoms with episodic and chronic cycles. DESIGN/METHODS: This retrospective analysis used insurance claims from Truven Health Analytics MarketScan® research databases from 2009 to 2014. Two cohorts were compared: CH patients (with ≥2 CH claims) were propensity score matched with 4 non-headache controls, all with continuous enrollment for 12 months before and after the date of first CH claim or matched period among controls. RESULTS: CH patients (N = 7589) were mainly male (57.4%) and 35-64 years old (73.2%), with significantly more claims for comorbid conditions vs controls (N = 30,341), including depressive disorders (19.8% vs 10.0%), sleep disturbances (19.7% vs 9.1%), anxiety disorders (19.2% vs 8.7%), and tobacco use disorders (12.8% vs 5.3%), with 2.5 times greater odds of suicidal ideation (all P < .0001). Odds of drug dependence were 3-fold greater among CH patients (OR = 2.8 [95% CI 2.3-3.4, P < .0001]). CH patients reported significantly greater use of prescription medications compared with controls; 25% of CH patients had >12 unique prescription drug claims. Most commonly prescribed drug classes for CH patients included: opiate agonists (41%), corticosteroids (34%), 5HT-1 agonists (32%), antidepressants (31%), NSAIDs (29%), anticonvulsants (28%), calcium antagonists (27%), and benzodiazepines (22%). Only 30.4% of CH patients received recognized CH treatments without opioids during the 12-month post-index period. These patients were less likely to visit emergency departments or need hospitalizations (26.8%) as compared to CH patients with no pharmacy claims for recognized CH treatments or opioids (33.6%; P < .0001). CONCLUSIONS: The burden of CH is associated with significant co-morbidity, including substance use disorders and suicidal ideation, and treatment patterns indicating low use of recognized CH treatments.

Pathophysiological mechanisms of headache in patients with HIV.

BACKGROUND: The pathophysiology of human immunodeficiency virus (HIV) is complex. The etiology of headache in the HIV population is often multifactorial, and attributing causality to specific pathophysiological mechanisms is challenging. Headaches can occur any time during the infection and may be primary (as in non-HIV-infected patients) or secondary (either from HIV directly or due to opportunistic disease). DISCUSSION: Direct HIV related headaches are due to the underlying viral pathophysiology. For example, acute meningitis can be seen during HIV-1 seroconversion. Headaches can occur during symptomatic HIV and also after an AIDS-defining illness. Late-stage HIV headache can occur without any pleocytosis. A correlation between viral load and neurological symptoms including headache has been suggested. There may be similar mechanisms involving migraine, tension-type headache, and HIV infection. CONCLUSION: Secondary HIV headaches can be related to opportunistic infections, malignancy, medications used to treat HIV, and immune restoration inflammatory syndrome.

New daily persistent headache and potential new therapeutic agents.

New daily persistent headache is a form of a chronic daily headache with a unique temporal profile. Patients can recall the exact day when their headache started. It can be one of the most refractory types of headache to treat. Recent publications have highlighted different subtypes and heterogeneity in presentation. Referring to it as a syndrome versus a distinct disorder has also been suggested. Several different classes of medications have been used for the treatment, with mixed results. The underlying pathophysiology of new daily persistent headache is unclear, but tumor necrosis factor may play a role. The clinical features, differential diagnosis and potential new therapeutic agents will be discussed.