Droxidopa or Atomoxetine for Refractory Hypotension in Critically Ill Cardiothoracic Surgery Patients.

OBJECTIVE: To evaluate the effects of droxidopa or atomoxetine on intravenous (IV) vasoactive agent discontinuation in cardiothoracic intensive care unit (ICU) patients with hypotension refractory to midodrine. DESIGN: Single-center, retrospective cohort study. SETTING: Tertiary- and quaternary-care university teaching hospital. PARTICIPANTS: Included patients who received at least 4 consecutive doses of droxidopa or atomoxetine and remained on concurrent midodrine. Patients were excluded if they received study medication before admission, had clinical deterioration after study medication initiation requiring additional vasoactives/escalation of IV vasoactive dosage for at least 12 hours, had a diagnosis of hepatorenal syndrome, were prisoners, or were pregnant. INTERVENTIONS: Droxidopa, atomoxetine, or both. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was time to discontinuation of IV vasoactive agents after initiation of study medication, analyzed using a Kaplan-Meier estimate with the Wilcoxon method, censoring death within 24 hours of the last dose of study medication. No adjustment for repetitive analyses was made, as the analysis was hypothesis-generating. Of the 72 charts reviewed, 45 patients met inclusion criteria (18 atomoxetine, 17 droxidopa, and 10 both). There were no differences in median time to discontinuation of IV vasoactive agents (21.9 days v 8.0 days v 13.9 days, respectively; p = 0.259) or ICU or hospital length of stay between groups. A higher percentage of patients who survived to hospital discharge received both study medications or droxidopa alone (90% v 76.5%) than atomoxetine alone (44.4%, p = 0.028). CONCLUSIONS: Droxidopa and atomoxetine are oral vasoactive agents with potential mechanisms to facilitate IV vasopressor weaning for patients in the ICU with hypotension refractory to midodrine, but further prospective research is needed.

Safety and efficacy of ampreloxetine in symptomatic neurogenic orthostatic hypotension: a phase 2 trial.

PURPOSE: In neurogenic orthostatic hypotension, blood pressure falls when upright owing to impaired release of norepinephrine, leading to dizziness. Ampreloxetine, a selective norepinephrine reuptake inhibitor, increases circulating norepinephrine levels. This study explored the safety of ampreloxetine and its effect on blood pressure and symptoms in patients with neurogenic orthostatic hypotension. METHODS: A multicenter ascending-dose trial (range 1-20 mg, Part A) was followed by a 1 day, double-blind, randomized, placebo-controlled study (median dose 15 mg, Part B). Eligible patients then enrolled in a 20-week, open-label, steady-state extension phase (median dose 10 mg, Part C) followed by a 4-week withdrawal. Assessments included the Orthostatic Hypotension Symptom Assessment Scale (item 1), supine/seated/standing blood pressure, and safety. RESULTS: Thirty-four patients (age 66 ± 8 years, 22 men) were enrolled. Part A: The proportion of participants with a positive response (i.e., increase from baseline in seated systolic blood pressure of ≥ 10 mmHg) was greater with the 5 and 10 mg ampreloxetine doses than with placebo or other active ampreloxetine doses. Part B: Seated blood pressure increased 15.7 mmHg 4 h after ampreloxetine and decreased 14.2 mmHg after placebo [least squares mean difference (95% CI) 29.9 mmHg (7.6-52.3); P = 0.0112]. Part C: Symptoms of dizziness/lightheadedness improved 3.1 ± 3.0 points from baseline and standing systolic blood pressure increased 11 ± 12 mmHg. After 4 weeks of withdrawal, symptoms returned to pretreatment levels. The effect of ampreloxetine on supine blood pressure was minimal throughout treatment duration. CONCLUSION: Ampreloxetine was well tolerated and improved orthostatic symptoms and seated/standing blood pressure with little change in supine blood pressure. TRIAL REGISTRATION: NCT02705755 (first posted March 10, 2016).

Cognitive and Behavioral Changes in Patients Treated With Droxidopa for Neurogenic Orthostatic Hypotension: A Retrospective Review.

BACKGROUND: Droxidopa is a norepinephrine precursor that improves symptoms of neurogenic orthostatic hypotension in conditions such as Parkinson disease, multiple system atrophy, and pure autonomic failure by inducing a pressor effect. Unlike other pressor agents, droxidopa crosses the blood-brain barrier; however, its central effects are, as of yet, uncharacterized. OBJECTIVE: We present the results of a retrospective cohort study examining cognitive and behavioral side effects linked to droxidopa therapy. METHODS: We performed a review of 101 patients who had been treated with droxidopa at an academic tertiary care center and identified cases of cognitive and behavioral changes associated with the therapy. RESULTS: We identified six patients who had developed cognitive and behavioral symptoms, including memory difficulties, confusion, mania, and irritability, shortly after droxidopa initiation. All six patients displayed symptoms of synucleinopathy, manifesting with autonomic failure, rapid eye movement sleep behavior disorder, and parkinsonism. Patients had no significant cognitive or behavioral symptoms before droxidopa initiation. Behavioral disturbances were observed early in the droxidopa titration period and at relatively low doses. Symptoms resolved with dose reduction in four patients, and droxidopa was discontinued in two patients due to persistent irritability. No other medical comorbidities or alternative etiologies were identified to explain the symptoms. CONCLUSIONS: Droxidopa is designed to act peripherally as a pressor agent but may also exert important central effects. We hypothesize that the cognitive and behavioral manifestations observed in the patients with orthostatic hypotension resulted from an "overdose" of key noradrenergic networks linking orbitofrontal and mesolimbic regions.

Initiation of droxidopa during hospital admission for management of refractory neurogenic orthostatic hypotension in severely ill patients.

Orthostatic hypotension (OH) is a common cause of hospitalization, particularly in the elderly. Hospitalized patients with OH are often severely ill, with complex medical comorbidities and high rates of disability. Droxidopa is a norepinephrine precursor approved for the treatment of neurogenic OH (nOH) associated with autonomic failure that is commonly used in the outpatient setting, but there are currently no data regarding the safety and efficacy of droxidopa initiation in medically complex patients. We performed a retrospective review of patients started on droxidopa for refractory nOH while hospitalized at Vanderbilt University Medical Center between October 2014 and May 2017. Primary outcome measures were safety, change in physician global impression of illness severity from admission to discharge, and persistence on medication after 180-day follow-up. A total of 20 patients were identified through chart review. Patients were medically complex with high rates of cardiovascular comorbidities and a diverse array of underlying autonomic diagnoses. Rapid titration of droxidopa was safe and well tolerated in this cohort, with no cardiovascular events or new onset arrhythmias. Supine hypertension requiring treatment occurred in four patients. One death occurred during hospital admission due to organ failure associated with end-stage amyloidosis. Treating physicians noted improvements in presyncopal symptoms in 80% of patients. After 6 months, 13 patients (65%) continued on droxidopa therapy. In a retrospective cohort of hospitalized, severely ill patients with refractory nOH, supervised rapid titration of droxidopa was safe and effective. Treatment persistence was high, suggesting that symptomatic benefit extended beyond acute intervention.

Standing and Supine Blood Pressure Outcomes Associated With Droxidopa and Midodrine in Patients With Neurogenic Orthostatic Hypotension: A Bayesian Meta-analysis and Mixed Treatment Comparison of Randomized Trials.

BACKGROUND: The comparative effects of droxidopa and midodrine on standing systolic blood pressure (sSBP) and risk of supine hypertension in patients with neurogenic orthostatic hypotension (NOH) are unknown. OBJECTIVE: To perform a Bayesian mixed-treatment comparison meta-analysis of droxidopa and midodrine in the treatment of NOH. METHODS: The PubMed, CENTRAL, and EMBASE databases were searched up to November 16, 2016. Study selection consisted of randomized trials comparing droxidopa or midodrine with placebo and reporting on changes in sSBP and supine hypertension events. Data were pooled to perform a comparison among interventions in a Bayesian fixed-effects model using vague priors and Markov chain Monte Carlo simulation with Gibbs sampling, calculating pooled mean changes in sSBP and risk ratios (RRs) for supine hypertension with associated 95% credible intervals (CrIs). RESULTS: Six studies (4 administering droxidopa and 2 administering midodrine) enrolling a total of 783 patients were included for analysis. The mean change from baseline in sSBP was significantly greater for both drugs when compared with placebo (droxidopa 6.2 mm Hg [95% CrI = 2.4-10] and midodrine 17 mm Hg [95% CrI = 11.4-23]). Comparative analysis revealed a significant credible difference between droxidopa and midodrine. The RR for supine hypertension was significantly greater for midodrine, but not droxidopa, when compared with placebo (droxidopa RR = 1.4 [95% CrI = 0.7-2.7] and midodrine RR = 5.1 [95% CrI = 1.6-24]). Conclusion and Relevance: In patients with NOH, both droxidopa and midodrine significantly increase sSBP, the latter to a greater extent. However, midodrine, but not droxidopa, significantly increases risk of supine hypertension.

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.

Long-term safety of droxidopa in patients with symptomatic neurogenic orthostatic hypotension.

The long-term safety of droxidopa for the treatment of symptomatic neurogenic orthostatic hypotension in patients with Parkinson disease, pure autonomic failure, multiple system atrophy, or nondiabetic autonomic neuropathy was evaluated in a phase 3, multinational, open-label study in patients who previously participated in a double-blind, placebo-controlled clinical trial of droxidopa. A total of 350 patients received droxidopa 100 to 600 mg three times daily. Mean duration of droxidopa exposure was 363 days (range, 2-1133 days). Rates of serious adverse events (AEs), cardiac-related AEs, and supine hypertension were 24%, 5%, and 5%, respectively. Most AEs, including those of a cardiovascular nature, were not attributed by investigators to droxidopa. In this large cohort of patients with neurogenic orthostatic hypotension, droxidopa was well tolerated during long-term use.

Safety and Durability of Effect with Long-Term, Open-Label Droxidopa Treatment in Patients with Symptomatic Neurogenic Orthostatic Hypotension (NOH303).

BACKGROUND: Neurogenic orthostatic hypotension (nOH) is associated with insufficient norepinephrine release in response to postural change. OBJECTIVE: The objective of this study was to evaluate the long-term safety and durability of efficacy of the norepinephrine precursor droxidopa in patients with symptomatic nOH. METHODS: This multinational study consisted of 3 sequential phases: a 3-month open-label droxidopa treatment phase followed by a 2-week double-blind, placebo-controlled withdrawal phase, and a 9-month open-label extension phase in which all patients received droxidopa. Patients were adults diagnosed with symptomatic nOH associated with Parkinson's disease, multiple system atrophy, pure autonomic failure, dopamine ß-hydroxylase deficiency, or nondiabetic autonomic neuropathy. Efficacy was evaluated using patient- and investigator-reported questionnaire responses and the orthostatic standing test. Safety was assessed through adverse event (AE) reports and vital signs. RESULTS: A total of 102 patients received treatment with droxidopa. Initial improvements from baseline in patient-reported nOH symptom severity and impact on daily activities, evaluated using the Orthostatic Hypotension Questionnaire, exceeded 50% and were maintained throughout the 12-month study. Decreased nOH severity was also reflected in clinician and patient ratings on the Clinical Global Impression questionnaire. Standing systolic and diastolic blood pressures were increased from baseline throughout the study with droxidopa treatment. The most frequently reported AEs were falls, urinary tract infection, and headache. There was a low incidence (≤2%) of cardiac AEs (eg, first-degree atrioventricular block, supraventricular extrasystoles). CONCLUSIONS: Long-term, open-label treatment with droxidopa for up to 12 months was generally well tolerated and provided durable improvements in nOH signs and symptoms.

Analysis of number needed to treat for droxidopa in patients with symptomatic neurogenic orthostatic hypotension.

BACKGROUND: Droxidopa is an orally active prodrug that significantly improved dizziness/lightheadedness measured using the Orthostatic Hypotension Symptom Assessment (OHSA) Item 1 in patients with neurogenic orthostatic hypotension (nOH) caused by primary autonomic failure (Parkinson disease, multiple system atrophy, and pure autonomic failure), dopamine ß-hydroxylase deficiency, or nondiabetic autonomic neuropathy. The efficacy and safety of droxidopa were assessed by determining the number needed to treat (NNT) and the number needed to harm (NNH). METHODS: Data collected in randomized, placebo-controlled clinical studies in adults with a clinical diagnosis of symptomatic nOH were pooled for efficacy and safety analyses. NNT and NNH were calculated as reciprocals of the risk difference (difference in event rates) for droxidopa versus placebo. RESULTS: The NNT for droxidopa for improvement in OHSA Item 1 was <10. The NNH for adverse events (AEs) leading to discontinuation in the pooled studies was 81. The likelihood of being helped or harmed (LHH) calculated from pooled analysis of the NNT for ≥2 units of improvement in OHSA Item 1 score and the NNH for discontinuations due to AEs were 7.8, 8.8, 3.1, and 3.5 for weeks 1, 2, 4, and 8 after randomization, respectively. CONCLUSIONS: Droxidopa is efficacious for treatment of nOH, with an NNT below 10 and an acceptable tolerability profile with NNH ranging from 23 to 302 in the pooled analysis of frequently occurring AEs. Based on the LHH for the pooled analysis at week 1, droxidopa is 7.8 times more likely than placebo to show a clinical benefit than result in discontinuation because of an AE. TRIAL REGISTRATIONS: ClinicalTrials.gov identifiers: NCT00782340 , first received October 29, 2008; NCT00633880 , first received March 5, 2008; and NCT01176240 , first received July 30, 2010.

Droxidopa for orthostatic hypotension: a systematic review and meta-analysis.

OBJECTIVE: The systematic review and meta-analysis aims to determine the efficacy and safety of droxidopa in the treatment of orthostatic hypotension, following its recent approvals in the United States. METHODS: MEDLINE, EMBASE, PubMed, Cochrane Controlled Trials Register, Web of Science, ProQuest, and the WHO Clinical Trials Registry were searched. Studies were included if they randomized adults with orthostatic hypotension to droxidopa or to control, and outcomes related to symptoms, daily activity, blood pressure, or adverse events. Data were extracted independently by two reviewers. Risk of bias was judged against the Cochrane risk of bias tool and quality of evidence measured using Grading of Recommendations Assessment, Development and Evaluation criteria. A fixed-effects model was used for pooled analysis. RESULTS: Of 224 identified records, four studies met eligibility, with a pooled sample size of 494. Study duration was between 1 and 8 weeks. Droxidopa was effective at reducing dizziness [mean difference -0.97 (95% confidence interval -1.51, -0.42)], overall symptoms [-0.52 (-0.98, -0.06)] and difficulty with activity [-0.86 (-1.34, -0.38)]. Droxidopa was also effective at improving standing SBP [3.9 (0.1, 7.69)]. Rates of adverse events were similar between droxidopa and control groups, including supine hypertension [odds ratio 1.93 (0.87, 4.25)]. CONCLUSION: Droxidopa is well tolerated and effective at reducing the symptoms associated with neurogenic orthostatic hypotension without increasing the risk of supine hypertension. REGISTRATION: PROSPERO ID CRD42015024612.

Droxidopa for neurogenic orthostatic hypotension: a randomized, placebo-controlled, phase 3 trial.

OBJECTIVE: To determine whether droxidopa, an oral norepinephrine precursor, improves symptomatic neurogenic orthostatic hypotension (nOH). METHODS: Patients with symptomatic nOH due to Parkinson disease, multiple system atrophy, pure autonomic failure, or nondiabetic autonomic neuropathy underwent open-label droxidopa dose optimization (100-600 mg 3 times daily), followed, in responders, by 7-day washout and then a 7-day double-blind trial of droxidopa vs placebo. Outcome measures included patient self-ratings on the Orthostatic Hypotension Questionnaire (OHQ), a validated, nOH-specific tool that assesses symptom severity and symptom impact on daily activities. RESULTS: From randomization to endpoint (n = 162), improvement in mean OHQ composite score favored droxidopa over placebo by 0.90 units (p = 0.003). Improvement in OHQ symptom subscore favored droxidopa by 0.73 units (p = 0.010), with maximum change in "dizziness/lightheadedness." Improvement in symptom-impact subscore favored droxidopa by 1.06 units (p = 0.003), with maximum change for "standing a long time." Mean standing systolic blood pressure (BP) increased by 11.2 vs 3.9 mm Hg (p < 0.001), and mean supine systolic BP by 7.6 vs 0.8 mm Hg (p < 0.001). At endpoint, supine systolic BP >180 mm Hg was observed in 4.9% of droxidopa and 2.5% of placebo recipients. Adverse events reported in ≥ 3% of double-blind droxidopa recipients were headache (7.4%) and dizziness (3.7%). No patients discontinued double-blind treatment because of adverse events. CONCLUSIONS: In patients with symptomatic nOH, droxidopa improved symptoms and symptom impact on daily activities, with an associated increase in standing systolic BP, and was generally well tolerated. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that in patients with symptomatic nOH who respond to open-label droxidopa, droxidopa improves subjective and objective manifestation of nOH at 7 days.

Neurogenic orthostatic hypotension in Parkinson's disease: evaluation, management, and emerging role of droxidopa.

Neurogenic orthostatic hypotension (nOH) is due to failure of the autonomic nervous system to regulate blood pressure in response to postural changes due to an inadequate release of norepinephrine, leading to orthostatic hypotension and supine hypertension. nOH is common in Parkinson's disease (PD). Prevalence varies throughout the course of PD, ranging from 40% to 60%, and resulting in symptomatic nOH in approximately half. Symptomatic nOH, including lightheadedness, can limit daily activities and lead to falls. Symptomatic nOH can also limit therapeutic options for treating PD motor symptoms. Clinical evaluation should routinely include symptom assessment and blood pressure measurement of supine, sitting, and 3-minute standing; 24-hour ambulatory blood pressure monitoring can also be helpful. Non-pharmacological management of symptomatic nOH involves education, physical maneuvers, and adequate hydration. Current pharmacological treatment of symptomatic nOH includes salt supplement, fludrocortisone, midodrine, pyridostigmine, and other empiric medications. Despite these options, treatment of symptomatic nOH remains suboptimal, often limited by severe increases in supine blood pressure. Droxidopa, an oral prodrug converted by decarboxylation to norepinephrine, is a promising therapeutic option for symptomatic nOH in PD, improving symptoms of nOH, daily activities, falls, and standing systolic blood pressure in several recent trials. These trials demonstrated short-term efficacy and tolerability, with comparable increases in standing and supine blood pressures. Longer-term studies are ongoing to confirm durability of treatment effect.

L-dihydroxyphenylserine (Droxidopa): a new therapy for neurogenic orthostatic hypotension: the US experience.

Neurogenic orthostatic hypotension results from failure to release norepinephrine, the neurotransmitter of sympathetic postganglionic neurons, appropriately upon standing. In double blind, cross over, placebo controlled trials, administration of droxidopa, a synthetic amino acid that is decarboxylated to norepinephrine by the enzyme L: -aromatic amino acid decarboxylase increases standing blood pressure, ameliorates symptoms of orthostatic hypotension and improves standing ability in patients with neurogenic orthostatic hypotension due to degenerative autonomic disorders. The pressor effect results from conversion of droxidopa to norepinephrine outside the central nervous system both in neural and non-neural tissue. This mechanism of action makes droxidopa effective in patients with central and peripheral autonomic disorders.

[Pure akinesia presenting with antecollis].

We reported a 77-year-old woman having pure akinesia who presented with antecollis induced by L-threo-3, 4-dihydroxyphenylserine (L-DOPS). At the age of 70, she noticed increasing difficulty in standing up from a seat and moving. Afterward, she developed gait disturbance with difficulty in initiating walking, frozen gait, and postural instability. At 73 years of age, she came to our hospital, because she gradually fell down easily. Neurological examination disclosed mild akinesia with freezing symptom and kinésie paradoxale. No evidence of dementia, supranuclear gaze palsy, pseudobulbar palsy, rigidity, or tremor were present. As she developed akinesia, of which L-dopa therapy achieved little improvement, we clinically diagnosed as having pure akinesia. At age 74, L-DOPS was administered at a dose of 300mg per day and gradually increased up to 900mg per day, because her postural reflex was markedly disturbed and gait showed severe unsteadiness. Amelioration of frozen gait and unsteadiness were recognized, but efficacy of L-DOPS was temporal. It is well known that reported cases of pure akinesia were pathologically diagnosed as having progressive supranuclear palsy (PSP) or pallido-nigro-luysian atrophy. Therefore, the present case was suspected as having pathological changes which involved degeneration of the substantia nigra and globus pallidus. After three years of treatment with L-DOPS, at age 77, she was admitted to our hospital for abrupt onset of her dropped head. Hematological examinations were normal, cervical MRI showed no evidence of paracervical muscular atrophy, and electromyography did not demonstrate any abnormal change. In addition, her posterior cervical muscles showed abnormally high tension, so the dropped head was considered due to antecollis. After admission, antecollis disappeared rapidly following discontinuation of L-DOPS. However the mechanism of drug induced dystonia is imperfectly understood on the basis of the clinical course, L-DOPS was considered as possible cause of her antecollis. L-DOPS, artificial precursor of noradrenarine (NA), is thought to increase not only NA level in the CNS, but also inhibit release of acetylcholine. It is suggested that the antecollis of present case results from impairment of a normal dopaminergic-noradorenergic balance caused by increased NA and striatal dopamine deficiency. This is the first case of antecollis induced by L-DOPS in a pure akinesia patient, providing important information on mechanism of drug induced dystonia and indicating caution in the clinical use of L-DOPS.

Norepinephrine precursor therapy in neurogenic orthostatic hypotension.

BACKGROUND: In patients with neurogenic orthostatic hypotension (NOH), the availability of the sympathetic neurotransmitter norepinephrine (NE) in the synaptic cleft is insufficient to maintain blood pressure while in the standing posture. METHODS AND RESULTS: We determined the effect of oral administration of the synthetic amino acid L-threo-3,4-dihydroxyphenylserine (L-DOPS), which is decarboxylated to NE by the enzyme L-aromatic amino acid decarboxylase (L-AADC) in neural and nonneural tissue, on blood pressure and orthostatic tolerance in 19 patients with severe NOH (8 with pure autonomic failure and 11 with multiple-system atrophy). A single-blind dose-titration study determined the most appropriate dose for each patient. Patients were then enrolled in a double-blind, placebo-controlled, crossover trial. L-DOPS significantly raised mean blood pressure both supine (from 101+/-4 to 141+/-5 mm Hg) and standing (from 60+/-4 to 100+/-6 mm Hg) for several hours and improved orthostatic tolerance in all patients. After L-DOPS, blood pressure increases were closely associated with increases in plasma NE levels. Oral administration of carbidopa, which inhibits L-AADC outside the blood-brain barrier, blunted both the increase in plasma NE and the pressor response to L-DOPS in all patients CONCLUSIONS: Acute administration of L-DOPS increases blood pressure and improves orthostatic tolerance in patients with NOH. The pressor effect results from conversion of L-DOPS to NE outside the central nervous system.

Effects of L-threo-3,4-dihydroxyphenylserine on orthostatic hypotension in hemodialysis patients.

BACKGROUND: Orthostatic hypotension (OH) is a serious complication observed in hemodialysis (HD) patients after HD as well as during the interdialytic period. L-Threo-3,4-dihydroxyphenylserine (L-DOPS) is a nonphysiological neutral amino acid that is directly converted to the neurotransmitter norepinephrine by aromatic L-amino acid decarboxylase. METHODS: A placebo-controlled double-blind study for 4 consecutive weeks and a long-term study (24-52 weeks) were conducted to evaluate the efficacy of L-DOPS for OH after HD. The drug was administered orally 30 min before the start of each HD period in both studies. Doses of 400 mg of L-DOPS or placebo were given to HD patients with OH (45 and 41 patients, respectively) in the double-blind study, and doses of 200 or 400 mg of L-DOPS were given to 74 HD patients in the long-term study. RESULTS: In the double-blind study, L-DOPS significantly ameliorated subjective symptoms related to OH, including dizziness/light-headed feeling, and malaise, throughout the interdialytic period. For 19 patients with delayed-type OH, hypotension with the lowest blood pressure recorded 10 min after standing, the decrease in blood pressure was suppressed significantly after L-DOPS treatment (10 patients) as compared with the placebo-treated group (9 patients). In the long-term study, the efficacy of L-DOPS was not attenuated, and the marked fluctuations in the plasma L-DOPS and norepinephrine levels were not noted after long-term use, without increases in incidence or severity of adverse reactions. CONCLUSIONS: These results indicate that L-DOPS is effective for improving OH-related interdialytic subjective symptoms in HD patients after short-term as well as after long-term administration.

L-threo-dihydroxyphenylserine (L-threo-DOPS; droxidopa) in the management of neurogenic orthostatic hypotension: a multi-national, multi-center, dose-ranging study in multiple system atrophy and pure autonomic failure.

This study was designed to determine the efficacy and tolerability of increasing doses of L-threo-dihydroxyphenylserine (L-threo-DOPS) in treating symptomatic orthostatic hypotension associated with multiple system atrophy (MSA) and pure autonomic failure (PAF). Following a one-week run-in, patients (26 MSA; 6 PAF) with symptomatic orthostatic hypotension received increasing doses of L-threo-DOPS (100, 200 and 300 mg, twice daily) in an open, dose-ranging study. Incremental dose adjustment (after weeks two and four of outpatient treatment) was based on clinical need until blood pressure (BP), and symptoms improved. Final dosage was maintained for six weeks. With L-threo-DOPS, systolic BP decrease was reduced during orthostatic challenge (-22+/-28 mm Hg reduction from a baseline decrease of 54.3+/-27.7 mm Hg, p = 0.0001, n = 32; supine systolic BP at final visit was 118.9+/-28.2 mm Hg). By the end of the study, 25 patients (78%) improved, and in 14 patients (44%) orthostatic hypotension was no longer observed. Decreased orthostatic systolic BP decrease occurred in 22% (7/32), 24% (6/25) and 61% (11/18) of patients treated with 100, 200, and 300 mg L-threo-DOPS twice daily, respectively. An improvement occurred in symptoms associated with orthostatic hypotension, such as light-headedness, dizziness (p = 0.0125), and blurred vision (p = 0.0290). L-threo-DOPS was well tolerated, with the 2 serious adverse events reported being a possible complication of the disease under study, and with no reports of supine hypertension. In conclusion, L-threo-DOPS (100, 200, and 300 mg, twice daily) was well tolerated. The dosage of 300 mg twice daily L-threo-DOPS seemed to offer the most effective control of symptomatic orthostatic hypotension in MSA and PAF.