Six-Month Use of Droxidopa for Neurogenic Orthostatic Hypotension

Dysautonomia in COVID-19 Patients: A Narrative Review on Clinical Course, Diagnostic and Therapeutic Strategies

Introduction

On March 11, 2020, the World Health Organization sounded the COVID-19 pandemic alarm. While efforts in the first few months focused on reducing the mortality of infected patients, there is increasing data on the effects of long-term infection (Post-COVID-19 condition). Among the different symptoms described after acute infection, those derived from autonomic dysfunction are especially frequent and limiting.

Objective

To conduct a narrative review synthesizing current evidence of the signs and symptoms of dysautonomia in patients diagnosed with COVID-19, together with a compilation of available treatment guidelines.

Results

Autonomic dysfunction associated with SARS-CoV-2 infection occurs at different temporal stages. Some of the proposed pathophysiological mechanisms include direct tissue damage, immune dysregulation, hormonal disturbances, elevated cytokine levels, and persistent low-grade infection. Acute autonomic dysfunction has a direct impact on the mortality risk, given its repercussions on the respiratory, cardiovascular, and neurological systems. Iatrogenic autonomic dysfunction is a side effect caused by the drugs used and/or admission to the intensive care unit. Finally, late dysautonomia occurs in 2.5% of patients with Post-COVID-19 condition. While orthostatic hypotension and neurally-mediated syncope should be considered, postural orthostatic tachycardia syndrome (POTS) appears to be the most common autonomic phenotype among these patients. A review of diagnostic and treatment guidelines focused on each type of dysautonomic condition was done.

Conclusion

Symptoms deriving from autonomic dysfunction involvement are common in those affected by COVID-19. These symptoms have a great impact on the quality of life both in the short and medium to long term. A better understanding of the pathophysiological mechanisms of Post-COVID manifestations that affect the autonomic nervous system, and targeted therapeutic management could help reduce the sequelae of COVID-19, especially if we act in the earliest phases of the disease.

Evaluating the Impact of Orthostatic Syncope and Presyncope on Quality of Life: A Systematic Review and Meta-Analysis

PURPOSE

Syncope (transient loss of consciousness and postural tone) and presyncope are common manifestations of autonomic dysfunction that are usually triggered by orthostasis. The global impact of syncope on quality of life (QoL) is unclear. In this systematic review, we report evidence on the impact of syncope and presyncope on QoL and QoL domains, identify key factors influencing QoL in patients with syncopal disorders, and combine available data to compare QoL between syncopal disorders and to population normative data.

METHODS

A comprehensive literature search of academic databases (MEDLINE (PubMed), Web of Science, CINAHL, PsycINFO, and Embase) was conducted (February 2021) to identify peer-reviewed publications that evaluated the impact of vasovagal syncope (VVS), postural orthostatic tachycardia syndrome (POTS), or orthostatic hypotension (OH) on QoL. Two team members independently screened records for inclusion and extracted data relevant to the study objectives.

RESULTS

From 12,258 unique records identified by the search, 36 studies met the inclusion criteria (VVS: n = 20; POTS: n = 13; VVS and POTS: n = 1; OH: n = 2); 12 distinct QoL instruments were used. Comparisons of QoL scores between patients with syncope/presyncope and a control group were performed in 16 studies; significant QoL impairments in patients with syncope/presyncope were observed in all studies. Increased syncopal event frequency, increased autonomic symptom severity, and the presence of mental health disorders and/or comorbidities were associated with lower QoL scores.

CONCLUSION

This review synthesizes the negative impact of syncope/presyncope on QoL and identifies research priorities to reduce the burden of these debilitating disorders and improve patient QoL.

Durability of the Clinical Benefit of Droxidopa for Neurogenic Orthostatic Hypotension During 12 Weeks of Open-Label Treatment

Introduction

Droxidopa is approved to treat neurogenic orthostatic hypotension (nOH) symptoms in patients with autonomic failure based on short-term clinical trial data. Additional data on the long-term efficacy of droxidopa are needed. We have evaluated the 12-week efficacy and tolerability of droxidopa in patients with nOH in an open-label period of an ongoing phase 4 study .

Methods

Patients received 12 weeks of open-label treatment with an individually optimized droxidopa dose (100–600 mg, 3 times daily) as identified during a preceding titration period. Patient-reported outcomes included the Orthostatic Hypotension Symptom Assessment (OHSA), Orthostatic Hypotension Daily Activity Scale (OHDAS), and clinician- and patient-rated Clinical Global Impression–Severity (CGI-S) scales. Supine blood pressure (BP) and adverse events (AEs) were recorded.

Results

Data from 114 patients enrolled into the 12-week open-label period were available for analyses. After 12 weeks of droxidopa treatment, patients reported significant (P < 0.0001) improvements from baseline in OHSA and OHDAS composite and individual item scores and on clinician and patient CGI-S scores. Mean ± SD supine systolic and diastolic BP at week 12 increased by 15.5 ± 22.9 and 7.8 ± 11.7 mmHg from baseline, respectively (P < 0.0001 for both). The most frequently reported AEs were falls (17%), headache (13%), and dizziness (9%); one (0.9%) patient reported an AE of supine hypertension.

Conclusion

During 12 weeks of open-label treatment, droxidopa was associated with significant improvement from baseline in nOH symptoms and activities of daily living. No clinically important changes in supine hypertension or AEs of concern were observed. These results support the efficacy of droxidopa beyond 2 weeks of treatment.

Trial Registration

NCT02586623.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00317-5.

Psychometric validation of a patient-reported single-item assessment of 'Good Day Bad Day' in a neurogenic orthostatic hypotension population treated with droxidopa

BACKGROUND

Symptoms of neurogenic orthostatic hypotension (nOH), including lightheadedness/dizziness, presyncope, syncope, and falls, can lead to impaired functional ability and reduced quality of life. Because the severity and frequency of nOH symptoms fluctuate, it may be difficult for patients to accurately quantify the effect of symptoms on their daily lives using available outcome measures. A new single-item instrument, the 'Good Day Bad Day,' was developed, and its psychometric validity was assessed in patients with nOH.

METHODS

Data from a 6-month, prospective, observational cohort study of patients with nOH who were newly initiating droxidopa treatment were used. Patients were asked to quantify the number of good and bad days in the previous 7 days and responded to other validated patient-reported outcomes instruments. The concurrent and discriminant validities and the stability of the Good Day Bad Day instrument were assessed.

RESULTS

A total of 153 patients were included in the analysis (mean [SD] age, 62.3 [17] years). Change in the number of good days moderately correlated with improvements in other patient-reported outcomes (rho value range, -0.38 to -0.61). When data were examined categorically (low vs high symptom severity), the mean number of good days was higher in subgroups representing low symptom severity across measures at 1, 3, and 6 months (all P ≤ 0.01).

CONCLUSIONS

The Good Day Bad Day instrument provided good discrimination at baseline and over time and may aid in assessment of the effects of nOH symptoms on patients.

Management of Orthostatic Hypotension in Parkinson's Disease

Orthostatic hypotension (OH) is a common non-motor feature of Parkinson's disease that may cause unexplained falls, syncope, lightheadedness, cognitive impairment, dyspnea, fatigue, blurred vision, shoulder, neck, or low-back pain upon standing. Blood pressure (BP) measurements supine and after 3 minutes upon standing screen for OH at bedside. The medical history and cardiovascular autonomic function tests ultimately distinguish neurogenic OH, which is due to impaired sympathetic nerve activity, from non-neurogenic causes of OH, such as hypovolemia and BP lowering drugs. The correction of non-neurogenic causes and exacerbating factors, lifestyle changes and non-pharmacological measures are the cornerstone of OH treatment. If these measures fail, pharmacological interventions (sympathomimetic agents and/or fludrocortisone) should be introduced stepwise depending on the severity of symptoms. About 50% of patients with neurogenic OH also suffer from supine and nocturnal hypertension, which should be monitored for with in-office, home and 24 h-ambulatory BP measurements. Behavioral measures help prevent supine hypertension, which is eventually treated with non-pharmacological measures and bedtime administration of short-acting anti-hypertensive drugs in severe cases. If left untreated, OH impacts on activity of daily living and increases the risk of syncope and falls. Supine hypertension is asymptomatic, but often limits an effective treatment of OH, increases the risk of hypertensive emergencies and, combined with OH, facilitates end-organ damage. A timely management of both OH and supine hypertension ameliorates quality of life and prevents short and long-term complications in patients with Parkinson's disease.

Management Strategies for Comorbid Supine Hypertension in Patients with Neurogenic Orthostatic Hypotension

PURPOSE OF REVIEW

In autonomic failure, neurogenic orthostatic hypotension (nOH) and neurogenic supine hypertension (nSH) are interrelated conditions characterized by postural blood pressure (BP) dysregulation. nOH results in a sustained BP drop upon standing, which can lead to symptoms that include lightheadedness, orthostatic dizziness, presyncope, and syncope. nSH is characterized by elevated BP when supine and, although often asymptomatic, may increase long-term cardiovascular and cerebrovascular risk. This article reviews the pathophysiology and clinical characteristics of nOH and nSH, and describes the management of patients with both nOH and nSH.

RECENT FINDINGS

Pressor medications required to treat the symptoms of nOH also increase the risk of nSH. Because nOH and nSH are hemodynamically opposed, therapies to treat one condition may exacerbate the other. The management of patients with nOH who also have nSH can be challenging and requires an individualized approach to balance the short- and long-term risks associated with these conditions. Approaches to manage neurogenic BP dysregulation include nonpharmacologic approaches and pharmacologic treatments. A stepwise treatment approach is presented to help guide neurologists in managing patients with both nOH and nSH.

Pharmacologic treatment of orthostatic hypotension

Neurogenic orthostatic hypotension (OH) is a disabling disorder caused by impairment of the normal autonomic compensatory mechanisms that maintain upright blood pressure. Nonpharmacologic treatment is always the first step in the management of this condition, but a considerable number of patients will require pharmacologic therapies. Denervation hypersensitivity and impairment of baroreflex buffering makes these patients sensitive to small doses of pressor agents. Understanding the underlying pathophysiology can help in selecting between treatment options. In general, patients with low "sympathetic reserve", i.e., those with peripheral noradrenergic degeneration (pure autonomic failure, Parkinson's disease) and low plasma norepinephrine, tend to respond better to "norepinephrine replacers" (midodrine and droxidopa). On the other hand, patients with relatively preserved "sympathetic reserve", i.e., those with impaired central autonomic pathways but spared peripheral noradrenergic fibers (multiple system atrophy) and normal or slightly reduced plasma norepinephrine, tend to respond better to "norepinephrine enhancers" (pyridostigmine, atomoxetine, and yohimbine). There is, however, a spectrum of responses within these extremes, and treatment should be individualized. Other nonspecific treatments include fludrocortisone and octreotide. The presence of associated clinical conditions, such as supine hypertension, heart failure, postprandial hypotension, PD, MSA, and diabetes need to be considered in the pharmacologic management of these patients.

Cardiovascular Safety Considerations in the Treatment of Neurogenic Orthostatic Hypotension

Neurogenic orthostatic hypotension (nOH), a drop in blood pressure upon standing resulting from autonomic malfunction, may cause debilitating symptoms that can affect independence in daily activities and quality-of-life. nOH may also be associated with cardiovascular comorbidities (e.g., supine hypertension, heart failure, diabetes, and arrhythmias), making treatment decisions complicated and requiring management that should be based on a patient's cardiovascular profile. Additionally, drugs used to treat the cardiovascular disorders (e.g., vasodilators, β-blockers) can exacerbate nOH and concomitant symptoms. When orthostatic symptoms are severe and not effectively managed with nonpharmacologic strategies (e.g., water ingestion, abdominal compression), droxidopa or midodrine may be effective. Droxidopa may be less likely than midodrine to exacerbate supine hypertension, based on conclusions of a limited meta-analysis. In conclusion, treating nOH in patients with cardiovascular conditions requires a balance between symptom relief and minimizing adverse outcomes.

Parkinson Disease and Orthostatic Hypotension in the Elderly: Recognition and Management of Risk Factors for Falls

Parkinson disease (PD) is often associated with postural instability and gait dysfunction that can increase the risk for falls and associated consequences, including injuries, increased burden on healthcare resources, and reduced quality of life. Patients with PD have nearly twice the risk for falls and associated bone fractures compared with their general population counterparts of similar age. Although the cause of falls in patients with PD may be multifactorial, an often under-recognized factor is neurogenic orthostatic hypotension (nOH). nOH is a sustained decrease in blood pressure upon standing whose symptomology can include dizziness/lightheadedness, weakness, fatigue, and syncope. nOH is due to dysfunction of the autonomic nervous system compensatory response to standing and is a consequence of the neurodegenerative processes of PD. The symptoms associated with orthostatic hypotension (OH)/nOH can increase the risk of falls, and healthcare professionals may not be aware of the real-world clinical effect of nOH, the need for routine screening, or the value of early diagnosis of nOH when treating elderly patients with PD. nOH is easily missed and, importantly, healthcare providers may not realize that there are effective treatments for nOH symptoms that could help lessen the fall risk resulting from the condition. This review discusses the burden of, and key risk factors for, falls among patients with PD, with a focus on practical approaches for the recognition, assessment, and successful management of OH/nOH. In addition, insights are provided as to how fall patterns can suggest fall etiology, thereby influencing the choice of intervention.

Real-world droxidopa or midodrine treatment persistence in patients with neurogenic orthostatic hypotension or orthostatic hypotension

BACKGROUND

Neurogenic orthostatic hypotension (nOH) is a subtype of orthostatic hypotension (OH) observed in the presence of neuropathy and is associated with increased risk of falling, impaired function, and poor quality of life. Droxidopa and midodrine are approved in the United States to treat symptomatic nOH and OH in adults, respectively. In this study, we compared the treatment persistence of droxidopa and midodrine.

METHODS

A retrospective analysis of patients prescribed either droxidopa or midodrine was conducted using the Symphony Health Solutions database (Symphony Health Solutions, Phoenix, AZ, USA). Inclusion criteria were (1) a pharmacy insurance claim in at least 16 consecutive quarters from mid-2014 to 2018 and (2) an active prescription for droxidopa or midodrine of ≥30 days' duration during that period. Treatment persistence was defined as the time to the first break in drug coverage of ≥45 days and was capped at 365 days.

RESULTS

Data from 2305 patients who received droxidopa and 117,243 patients who received midodrine were included in this analysis. Median (95% CI) treatment persistence was significantly longer in the droxidopa cohort versus the midodrine cohort (303 [274-325] vs 172 [169-176] days; P < 0.001). After adjustment for confounding factors, patients using droxidopa monotherapy (i.e., without any concomitant midodrine and/or fludrocortisone use) were 16% more likely to be persistent at any time point than patients using midodrine (P < 0.001).

CONCLUSIONS

In this real-world data analysis, patients using droxidopa without concomitant medications for OH were more likely to remain on treatment than patients on midodrine.

Neurogenic Orthostatic Hypotension in Parkinson Disease: A Primer

Parkinson disease (PD) is associated with a variety of motor and non-motor clinical manifestations, including cardiovascular autonomic dysfunction. Neurogenic orthostatic hypotension (nOH) is a potentially serious manifestation of cardiovascular sympathetic failure that occurs in approximately 30% of patients with PD. Here we review the pathophysiology and effects of the condition as well as treatment considerations for patients with PD and nOH. Screening for nOH using orthostatic symptom questionnaires, orthostatic blood pressure measurements, and specialized autonomic testing is beneficial for the identification of symptomatic and asymptomatic cases because cardiac sympathetic denervation and nOH can occur even at early (premotor) stages of PD. Symptoms of nOH, such as orthostatic lightheadedness, in patients with PD, have been shown to adversely affect patient safety (with increased risk of falls) and quality of life and should prompt treatment with non-pharmacologic and, occasionally, pharmacologic measures. Patients with nOH are also at increased risk of supine hypertension, which requires balancing various management strategies. FUNDING: Lundbeck (Deerfield, IL).