Octreotide effects on orthostatic hypotension in patients with multiple system atrophy: a controlled study of acute administration

Benefits and Risks of Medications Used in the Management of Hypotension: A Review

This comprehensive literature review addresses the scarcity and limited study of hypotension treatments compared to abundant antihypertensive drugs. Hypotension, categorized as absolute, relative, or orthostatic, has diverse causes. This review explores various treatments, including drugs affecting the sympathetic nervous system, such as midodrine, dihydroergotamine, and ergotamine, which have shown efficacy in managing hypotension. Dopamine agonists/antagonists and other drugs such as ephedrine, norepinephrine, and fludrocortisone are also discussed, each with distinct mechanisms and applications. Additionally, adjunctive agents such as non-steroidal anti-inflammatory agents, caffeine, and monoamine oxidase inhibitors are reviewed for their effects on blood pressure. This review underscores the importance of understanding the efficacy and safety profiles of hypotension treatments to guide healthcare professionals in optimal drug selection and management, emphasizing the need for further research and comparative studies for evidence-based guidelines.

Non-pharmacological and drug treatment of autonomic dysfunction in multiple system atrophy: current status and future directions

Multiple system atrophy (MSA) is a sporadic, fatal, and rapidly progressive neurodegenerative disease of unknown etiology that is clinically characterized by autonomic failure, parkinsonism, cerebellar ataxia, and pyramidal signs in any combination. Early onset and extensive autonomic dysfunction, including cardiovascular dysfunction characterized by orthostatic hypotension (OH) and supine hypertension, urinary dysfunction characterized by overactive bladder and incomplete bladder emptying, sexual dysfunction characterized by sexual desire deficiency and erectile dysfunction, and gastrointestinal dysfunction characterized by delayed gastric emptying and constipation, are the main features of MSA. Autonomic dysfunction greatly reduces quality of life and increases mortality. Therefore, early diagnosis and intervention are urgently needed to benefit MSA patients. In this review, we aim to discuss the systematic treatment of autonomic dysfunction in MSA, and focus on the current methods, starting from non-pharmacological methods, such as patient education, psychotherapy, diet change, surgery, and neuromodulation, to various drug treatments targeting autonomic nerve and its projection fibers. In addition, we also draw attention to the interactions among various treatments, and introduce novel methods proposed in recent years, such as gene therapy, stem cell therapy, and neural prosthesis implantation. Furthermore, we elaborate on the specific targets and mechanisms of action of various drugs. We would like to call for large-scale research to determine the efficacy of these methods in the future. Finally, we point out that studies on the pathogenesis of MSA and pathophysiological mechanisms of various autonomic dysfunction would also contribute to the development of new promising treatments and concepts.

Orthostatic Hypotension: Management of a Complex, But Common, Medical Problem

Orthostatic hypotension (OH), a common, often overlooked, disorder with many causes, is associated with debilitating symptoms, falls, syncope, cognitive impairment, and risk of death. Chronic OH, a cardinal sign of autonomic dysfunction, increases with advancing age and is commonly associated with neurodegenerative and autoimmune diseases, diabetes, hypertension, heart failure, and kidney failure. Management typically involves a multidisciplinary, patient-centered, approach to arrive at an appropriate underlying diagnosis that is causing OH, treating accompanying conditions, and providing individually tailored pharmacological and nonpharmacological treatment. We propose a novel streamlined pathophysiological classification of OH; review the relationship between the cardiovascular disease continuum and OH; discuss OH-mediated end-organ damage; provide diagnostic and therapeutic algorithms to guide clinical decision making and patient care; identify current gaps in knowledge and try to define future research directions. Using a case-based learning approach, specific clinical scenarios are presented highlighting various presentations of OH to provide a practical guide to evaluate and manage patients who have OH.

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.

Multiple system atrophy

Multiple system atrophy (MSA) is a sporadic, adult-onset, relentlessly progressive neurodegenerative disorder, clinically characterized by various combinations of autonomic failure, parkinsonism and ataxia. The neuropathological hallmark of MSA are glial cytoplasmic inclusions consisting of misfolded α-synuclein. Selective atrophy and neuronal loss in striatonigral and olivopontocerebellar systems underlie the division into two main motor phenotypes of MSA-parkinsonian type and MSA-cerebellar type. Isolated autonomic failure and REM sleep behavior disorder are common premotor features of MSA. Beyond the core clinical symptoms, MSA manifests with a number of non-motor and motor features. Red flags highly specific for MSA may provide clues for a correct diagnosis, but in general the diagnostic accuracy of the second consensus criteria is suboptimal, particularly in early disease stages. In this chapter, the authors discuss the historical milestones, etiopathogenesis, neuropathological findings, clinical features, red flags, differential diagnosis, diagnostic criteria, imaging and other biomarkers, current treatment, unmet needs and future treatments for MSA.

Evidence-based treatment of neurogenic orthostatic hypotension and related symptoms

Neurogenic orthostatic hypotension, postprandial hypotension and exercise-induced hypotension are common features of cardiovascular autonomic failure. Despite the serious impact on patient’s quality of life, evidence-based guidelines for non-pharmacological and pharmacological management are lacking at present. Here, we provide a systematic review of the literature on therapeutic options for neurogenic orthostatic hypotension and related symptoms with evidence-based recommendations according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Patient’s education and non-pharmacological measures remain essential, with strong recommendation for use of abdominal binders. Based on quality of evidence and safety issues, midodrine and droxidopa reach a strong recommendation level for pharmacological treatment of neurogenic orthostatic hypotension. In selected cases, a range of alternative agents can be considered (fludrocortisone, pyridostigmine, yohimbine, atomoxetine, fluoxetine, ergot alkaloids, ephedrine, phenylpropanolamine, octreotide, indomethacin, ibuprofen, caffeine, methylphenidate and desmopressin), though recommendation strength is weak and quality of evidence is low (atomoxetine, octreotide) or very low (fludrocortisone, pyridostigmine, yohimbine, fluoxetine, ergot alkaloids, ephedrine, phenylpropanolamine, indomethacin, ibuprofen, caffeine, methylphenidate and desmopressin). In case of severe postprandial hypotension, acarbose and octreotide are recommended (strong recommendation, moderate level of evidence). Alternatively, voglibose or caffeine, for which a weak recommendation is available, may be useful.

Critical appraisal of clinical trials in multiple system atrophy: Toward better quality

Multiple system atrophy (MSA) is a rare neurodegenerative disease of undetermined cause. Although many clinical trials have been conducted, there is still no treatment that cures the disease or slows its progression. We sought to assess the clinical trials, methodology, and quality of reporting of clinical trails conducted in MSA patients. We conducted a systematic review of all trials with at least 1 MSA patient subject to any pharmacological/nonpharmacological interventions. Two independent reviewers evaluated the methodological characteristics and quality of reporting of trials. A total of 60 clinical trials were identified, including 1375 MSA patients. Of the trials, 51% (n = 31) were single-arm studies. A total of 28% (n = 17) had a parallel design, half of which (n = 13) were placebo controlled. Of the studies, 8 (13.3%) were conducted in a multicenter setting, 3 of which were responsible for 49.3% (n = 678) of the total included MSA patients. The description of primary outcomes was unclear in 60% (n = 40) of trials. Only 10 (16.7%) clinical trials clearly described the randomization process. Blinding of the participants, personnel, and outcome assessments were at high risk of bias in the majority of studies. The number of dropouts/withdrawals was high (n = 326, 23.4% among the included patients). Overall, the design and quality of reporting of the reviewed studies is unsatisfactory. The most frequent clinical trials were small and single centered. Inadequate reporting was related to the information on the randomization process, sequence generation, allocation concealment, blinding of participants, and sample size calculations. Although improved during the recent years, methodological quality and trial design need to be optimized to generate more informative results. © 2017 International Parkinson and Movement Disorder Society.

The Treatment of Primary Orthostatic Hypotension

OBJECTIVE

To review the efficacy and safety of pharmacological and nonpharmacological strategies used to treat primary orthostatic hypotension (OH).

DATA SOURCES

A literature review using PubMed and MEDLINE databases searching hypotension, non-pharmacological therapy, midodrine, droxidopa, pyridostigmine, fludrocortisone, atomoxetine, pseudoephedrine, and octreotide was performed.

STUDY SELECTION AND DATA EXTRACTION

Randomized or observational studies, cohorts, case series, or case reports written in English between January 1970 and November 2016 that assessed primary OH treatment in adult patients were evaluated.

DATA SYNTHESIS

Based on the chosen criteria, it was found that OH patients make up approximately 15% of all syncope patients, predominantly as a result of cardiovascular or neurological insults, or offending medication. Nonpharmacological strategies are the primary treatment, such as discontinuing offending medications, switching medication administration to bedtime, avoiding large carbohydrate-rich meals, limiting alcohol, maintaining adequate hydration, adding salt to diet, and so on. If these fail, pharmacotherapy can help ameliorate symptoms, including midodrine, droxidopa, fludrocortisone, pyridostigmine, atomoxetine, sympathomimetic agents, and octreotide.

CONCLUSIONS

Midodrine and droxidopa possess the most evidence with respect to increasing blood pressure and alleviating symptoms. Pyridostigmine and fludrocortisone can be used in patients who fail to respond to these agents. Emerging evidence with low-dose atomoxetine is promising, especially in those with central autonomic failure, and may prove to be a viable alternative treatment option. Data surrounding other therapies such as sympathomimetic agents or octreotide are minimal. Medication management of primary OH should be guided by patient-specific factors, such as tolerability, adverse effects, and drug-drug and drug-disease interactions.

Toward disease modification in multiple system atrophy: Pitfalls, bottlenecks, and possible remedies

Multiple system atrophy has recently attracted increased attention in basic and clinical research. Understanding of key pathophysiological mechanismshas improved; and, in the past decade, the first clinical trials aiming at diseasemodification were conducted. However, there is still no established interventional therapy available. In this review, the authors summarize recent advances, discuss bottlenecks and possible pitfalls of previous interventional studies, and suggest future research avenues.

Orthostatic hypotension: managing a difficult problem

Orthostatic hypotension (OH) leads to a significant number of hospitalizations each year, and is associated with significant morbidity and mortality among affected individuals. Given the increased risk for cardiovascular events and falls, it is important to identify the underlying etiology of OH and to choose appropriate therapeutic agents. OH can be non-neurogenic or neurogenic (arising from a central or peripheral lesion). The initial evaluation includes orthostatic vital signs, complete history and a physical examination. Patients should also be evaluated for concomitant symptoms of post-prandial hypotension and supine hypertension. Non-pharmacologic interventions are the first step for treatment of OH. The appropriate selection of medications can also help with symptomatic relief. This review highlights the pathophysiology, clinical features, diagnostic work-up and treatment of patients with neurogenic OH.

Management of neurogenic orthostatic hypotension in patients with autonomic failure

The maintenance of blood pressure in the upright position requires intact autonomic cardiovascular reflexes. Diseases that affect the sympathetic innervation of the cardiovascular system result in a sustained fall in blood pressure upon standing (i.e., neurogenic orthostatic hypotension) that can impair the blood supply to the brain and other organs and cause considerable morbidity and mortality. Here we review treatment options for neurogenic orthostatic hypotension and include an algorithm for its management that emphasizes the importance of non-pharmacologic measures and provides guidance on pharmacologic treatment options.

A systematic review of the pharmacological management of orthostatic hypotension

OBJECTIVES

The 'short' and 'long-term' benefits of pharmacological interventions to treat orthostatic hypotension (OH) remain unclear. The aim was to systematically examine the published literature on the effectiveness of different drug regimens for the treatment of OH.

DESIGN

Systematic review.

SETTING

MEDLINE (1950-Week 7, 2011), EMBASE (1980-Week 7, 2011), CINAHL (1981-Week 7, 2011) databases and hand-searching of bibliographies were used to identify suitable papers.

PARTICIPANTS

Studies selected were those, which investigated drug treatment of OH in a single- or double-blind randomised controlled trial (RCT) in humans over 18 years of age.

MEASUREMENTS

Data were extracted from suitable full-text articles by three investigators independently.

RESULTS

The 13 trials met the criteria for systematic review amongst which was considerable variation in the size of postural blood pressure (BP) change with active treatment. However, there was evidence that commonly used drugs midodrine or fludrocortisone therapy did increase standing or head-up-tilt (HUT) systolic blood pressure in certain patient groups.

CONCLUSION

The evidence that pharmacological therapy is of benefit for the treatment of OH is limited by the lack of good quality clinical trial evidence. Further well-designed RCTs of pharmacological treatment of OH investigating the impact on postural symptoms as well as actual BP changes are needed.

The management of orthostatic hypotension in Parkinson's disease

Orthostatic hypotension (OH) is a common and disabling symptom affecting Parkinson's disease (PD) patients. We present the effect of the different therapies commonly used to manage PD on this clinical manifestation. For this purpose, we describe the relationship between OH and the current treatments employed in PD, such as L-DOPA, dopaminergic agonists, and continuous dopaminergic stimulation therapies. Additionally, we review the therapeutic measures that could be used to ameliorate OH. There are different approaches to deal with this manifestation, including pharmacological and non-pharmacological treatments, although none of them is specifically aimed for treating OH in PD.

Pharmacological options in the management of orthostatic hypotension in older adults

Orthostatic hypotension (OH) is a common disorder in older adults with potentially serious clinical consequences. Understanding the key underlying pathophysiological processes that predispose individuals to OH is essential when making treatment decisions for this group of patients. In this article, we discuss the key antihypotensive agents used in the management of OH in older adults. Commonly, midodrine is used as a first-line agent, given its supportive data in randomized, controlled trials. Fludrocortisone has been evaluated in open-label trials and has long-established usage in clinical practice. Other agents are available and in clinical use, either alone or in combination, but larger randomized trial evaluations are yet to be published. It is important to bear in mind that a patient may be taking medications that predispose to or exacerbate the symptoms of OH. Withdrawal of such medications, where possible, should be considered before commencing other pharmacological agents that attenuate the symptoms of OH.

Heterocyclic Analogues of N-(4-(4-(2,3-Dichlorophenyl)piperazin-1-yl)butyl)arylcarboxamides with Functionalized Linking Chains as Novel Dopamine D3 Receptor Ligands: Potential Substance Abuse Therapeutic Agents

Dopamine D3 receptor antagonists and partial agonists have been shown to modulate drug-seeking effects induced by cocaine and other abused substances. Compound 6 [PG01037, (N-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)-trans-but-2-enyl)-4-pyridine-2-ylbenzamide)] and related analogues are currently being evaluated in animal models of drug addiction. In these studies, a discrepancy between in vitro binding affinity, in vivo occupancy, and behavioral potency has been observed. The purpose of this study was to examine (1) modifications of the 2-pyridylphenyl moiety of 6 and (2) hydroxyl, acetyl, and cyclopropyl substitutions on the butylamide linking chain systematically coupled with 2-fluorenylamide or 2-pyridylphenylamide and 2-methoxy- or 2,3-dichloro-substituted phenylpiperazines to measure the impact on binding affinity, D2/D3 selectivity, lipophilicity, and function. In general, these modifications were well tolerated at the human dopamine D3 (hD3) receptor (Ki = 1-5 nM) as measured in competition binding assays. Several analogues showed >100-fold selectivity for dopamine D3 over D2 and D4 receptors. In addition, while all the derivatives with an olefinic linker were antagonists, in quinpirole-stimulated mitogenesis at hD3 receptors, several of the hydroxybutyl-linked analogues (16, 17, 21) showed partial agonist activity. Finally, several structural modifications reduced lipophilicities while retaining the desired binding profile.

EFNS guidelines on the diagnosis and management of orthostatic hypotension

Orthostatic (postural) hypotension (OH) is a common, yet under diagnosed disorder. It may contribute to disability and even death. It can be the initial sign, and lead to incapacitating symptoms in primary and secondary autonomic disorders. These range from visual disturbances and dizziness to loss of consciousness (syncope) after postural change. Evidence based guidelines for the diagnostic workup and the therapeutic management (non-pharmacological and pharmacological) are provided based on the EFNS guidance regulations. The final literature research was performed in March 2005. For diagnosis of OH, a structured history taking and measurement of blood pressure (BP) and heart rate in supine and upright position are necessary. OH is defined as fall in systolic BP below 20 mmHg and diastolic BP below 10 mmHg of baseline within 3 min in upright position. Passive head-up tilt testing is recommended if the active standing test is negative, especially if the history is suggestive of OH, or in patients with motor impairment. The management initially consists of education, advice and training on various factors that influence blood pressure. Increased water and salt ingestion effectively improves OH. Physical measures include leg crossing, squatting, elastic abdominal binders and stockings, and careful exercise. Fludrocortisone is a valuable starter drug. Second line drugs include sympathomimetics, such as midodrine, ephedrine, or dihydroxyphenylserine. Supine hypertension has to be considered.

Management of multiple system atrophy: state of the art

Multiple system atrophy (MSA) is a sporadic neurodegenerative disease of undetermined aetiology presenting with parkinsonian, autonomic, cerebellar, and pyramidal signs. Despite the lack of any effective therapy to reverse MSA, some of the symptoms may be improved with adequate symptomatic therapies. Medical treatment is largely aimed at mitigating the parkinsonian and autonomic features. The therapeutic results of levodopa therapy in cases of MSA are difficult to interpret because of their variability. Nevertheless, the simple statement that patients with MSA do not respond to levodopa is false. Clinical and pathologically proven series document levodopa efficacy in about 40-60% of patients with MSA and predominant parkinsonian features. Other antiparkinsonian compounds (dopamine agonists, amantadine) may also be employed, but they are not more effective than levodopa. Orthostatic hypotension (OH) can be suspected from the patient s history and subsequently documented in the clinic by measuring lying and standing blood pressure. The diagnosis ideally should be confirmed with additional laboratory tests to determine the cause and evaluate the functional deficit, so as to aid treatment. A number of pharmacological agents with different mechanisms of action have been used in MSA to reduce OH when this is symptomatic. OH can also be alleviated by avoiding aggravating factors, such as the effects of food, micturition, exposure to a warm environment, and physiological diurnal changes, and by using other non-pharmacological strategies. The treatment of the very common genitourinary symptoms (incontinence, retention, impotence) should also be considered in order to improve the quality of life of these patients.

Drug treatment of orthostatic hypotension because of autonomic failure or neurocardiogenic syncope

Orthostatic hypotension either because of autonomic failure or neurocardiogenic syncope can be very incapacitating and should be treated accordingly. Drug therapy is frequently needed to alleviate orthostatic symptoms. The physiopathological basis of neurocardiogenic syncope and of autonomic failure is completely different and their treatment should be distinct. In the past 5 years, many randomized, placebo-controlled trials have shed light on the efficacy of specific pressor drugs. In patients with orthostatic hypotension because of autonomic failure, alpha-adrenoceptor agonists, and midodrine in particular, have been shown to increase standing blood pressure and decrease orthostatic symptoms. Other drugs such as octreotide, indomethacin or ergotamine have also been shown to elevate standing blood pressure and/or orthostatic tolerance. Fludrocortisone is a well known and frequently used pressor drug but randomized controlled studies are needed to measure its efficacy. In patients with orthostatic hypotension associated with neurocardiogenic syncope, clinical trials have demonstrated that beta-blockers, especially beta(1)-selective agents without intrinsic sympathomimetic activity such as atenolol, midodrine and paroxetine can decrease recurrence of syncope. Treatment algorithms, such as those presented in this review, should always be interpreted in the light of individual patient characteristics. Many of the drugs used for orthostatic hypotension have multiple indications and contraindications that should influence therapeutic decisions. Little is known about the effectiveness and tolerability of specific combinations of pressor drugs. Consequently, sound clinical judgment and close follow-up of patients should always guide combination therapy.

Orthostatic Hypotension in Multiple System Atrophy

There is no known way to cure multiple system atrophy or even to slow its insidious progression, but there are opportunities to treat many of its symptoms and complications. Of all the autonomic disturbances it causes, orthostatic hypotension is associated with one of the better chances for successful intervention. Milder symptoms may be treated by nonpharmacologic means (eg, changes in diet and activities and compressive maneuvers and devices). Syncopal patients will require treatment with medications. Midodrine is the most effective drug. It is more physiologic and better tolerated, but much more expensive, than fludrocortisone. The latter is often beneficial but frequently causes lower limb edema. Low-dose propranolol is occasionally useful. Other drugs worth trying are indomethacin and intranasal desmopressin. The variety of measures available to treat orthostatic hypotension in multiple system atrophy affords physicians some prospect of easing the suffering of many patients with this otherwise disabling and discouraging disorder.

Effects of octreotide on experimental neurogenic orthostatic hypotension in anaesthetized dogs

This paper investigates the effects of octreotide (0.1 mg/kg, subcutaneous) on cardiovascular adaptation during head-up tilt test in an experimental model of neurogenic orthostatic hypotension (OH) obtained by chronic sinoaortic denervation in anaesthetized dogs. Blood pressure (BP), heart rate (HR), spectral variability (Fast Fourier transformation on 512 consecutive points, delta t: 2 Hz) and plasma catecholamine levels were measured in a double blind cross-over randomized study versus placebo, in supine position and during a head-up tilt test (80 degrees, 10 min) in six sinoaortic denervated and six control (normal) dogs. In normal dogs, head-up tilt test significantly increased HR and diastolic blood pressure (DBP). Plasma noradrenaline levels and energy of the low frequency band (40-150 mHz) of systolic blood pressure (SBP) significantly increased whereas the energy of the low frequency band of HR significantly decreased. Placebo and octreotide failed to modify supine and head-up tilt values of the measured parameters (except the value of low frequency band of SBP, which increased after octreotide). In sinoaortic denervated dogs, supine values of BP, HR and plasma noradrenaline levels were significantly higher than in controls whereas the energy of the low frequency spectral band of HR and SBP was similar to controls. Head-up tilt test induced a dramatic decrease in BP. HR, plasma noradrenaline levels and energy of the low frequency band of SBP and HR remained unchanged during head-up tilt tests. Neither supine nor head-up tilt values of these parameters were modified 45 min after octreotide or placebo administration. These results show that sinoaortic denervation is a reproducible model of OH characterized by a lack of activation of sympathetic efferent pathways during head-up tilt tests. Octreotide at the dose used remains ineffective to prevent the fall in BP under these experimental conditions.