COVID-19-induced postural orthostatic tachycardia syndrome treated with ivabradine.

A 22-year-old woman was referred with exertional dyspnoea and chest tightness 3 weeks following a diagnosis of COVID-19. Evaluation revealed a resting sinus tachycardia and criteria for postural orthostatic tachycardia syndrome were met. After non-pharmacological interventions failed to yield symptomatic improvement, ivabradine was commenced. This intervention was followed by a substantial improvement in the patient's exercise tolerance and energy levels and an objective reduction in supine and standing heart rate.

Radio emission from a pulsar's magnetic pole revealed by general relativity.

Binary pulsars are affected by general relativity (GR), causing the spin axis of each pulsar to precess. We present polarimetric radio observations of the pulsar PSR J1906+0746 that demonstrate the validity of the geometrical model of pulsar polarization. We reconstruct the (sky-projected) polarization emission map over the pulsar's magnetic pole and predict the disappearance of the detectable emission by 2028. Two tests of GR are performed using this system, including the spin precession for strongly self-gravitating bodies. We constrain the relativistic treatment of the pulsar polarization model and measure the pulsar beaming fraction, with implications for the population of neutron stars and the expected rate of neutron star mergers.

Extended-release guanfacine hydrochloride in 6-17-year olds with ADHD: a randomised-withdrawal maintenance of efficacy study.

BACKGROUND: Extended-release guanfacine hydrochloride (GXR), a selective α2A-adrenergic agonist, is a nonstimulant medication for attention-deficit/hyperactivity disorder (ADHD). This phase 3, double-blind, placebo-controlled, randomised-withdrawal study evaluated the long-term maintenance of GXR efficacy in children/adolescents with ADHD. METHODS: Children/adolescents (6-17 years) with ADHD received open-label GXR (1-7 mg/day). After 13 weeks, responders were randomised to GXR or placebo in the 26-week, double-blind, randomised-withdrawal phase (RWP). The primary endpoint was the percentage of treatment failure (≥50% increase in ADHD Rating Scale version IV total score and ≥2-point increase in Clinical Global Impression-Severity compared with RWP baseline, at two consecutive visits). The key secondary endpoint was time to treatment failure (TTF). TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01081145; EudraCT 2009-018161-12. RESULTS: A total of 528 participants enrolled; 316 (59.8%) entered the RWP. Treatment failure occurred in 49.3% of the GXR and 64.9% of the placebo group (p = 0.006). TTF was significantly longer in GXR versus placebo (p = 0.003). GXR was well tolerated. CONCLUSIONS: Guanfacine hydrochloride demonstrated long-term maintenance of efficacy compared with placebo in children/adolescents with ADHD. Implications of the placebo substitution design and findings with different ADHD medications are discussed.

Does Guanfacine Extended Release Impact Functional Impairment in Children with Attention-Deficit/Hyperactivity Disorder? Results from a Randomized Controlled Trial.

BACKGROUND: In clinical trials of medications to treat attention-deficit/hyperactivity disorder (ADHD) in children, effects on functional impairment have been less well-studied than changes in ADHD symptoms. OBJECTIVE: Data regarding functional impairment were analyzed from a multicenter, double-blind, placebo-controlled study of guanfacine extended release (GXR) in children with ADHD, using the Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P). The correspondence of changes in WFIRS-P scores with symptomatic and global response to GXR treatment was also examined, with treatment response defined by scores on both the ADHD Rating Scale IV (ADHD-RS-IV) and the Clinical Global Impressions-Improvement Scale (CGI-I). METHODS: In this 8-week, double-blind, placebo-controlled, dose optimization study at 47 sites across the USA and Canada, children aged 6-12 years with a diagnosis of ADHD [Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria, and an ADHD-RS-IV score ≥28 and CGI-Severity of Illness Scale score ≥4 at baseline], were randomized 1:1:1 into three groups: GXR AM [GXR (1-4 mg/day) in the morning, placebo in the evening], GXR PM [placebo in the morning, GXR (1-4 mg/day) in the evening], or twice-daily placebo. Parents rated their children on the WFIRS-P at screening, baseline, the end of dose optimization, and at the final on-treatment assessment. RESULTS: The efficacy population was composed of 333 subjects (GXR AM: n = 107; GXR PM: n = 114; placebo: n = 112). At the final on-treatment assessment, there were significant improvements from baseline in the placebo-adjusted difference in least-squares (LS) mean (95 % confidence interval) WFIRS-P Total scores for both GXR treatment groups combined [GXR all-active: -0.16 (-0.25, -0.07), effect size (ES) = 0.448, P <0.001] and separately [GXR AM: -0.15 (-0.26, -0.05), ES = 0.417, P = 0.004; GXR PM: -0.18 (-0.28, -0.07), ES = 0.478, P = 0.001]. Significant improvements in WFIRS-P domain scores for Family, Learning and School (including Academic Performance and Behavior in School), Social, and Risky Behavior were found for both GXR cohorts compared with placebo. However, the Life Skills and Self-Concept domain scores of the WFIRS-P did not improve with GXR treatment. Post hoc stratification by responder status revealed that significant (P <0.001) improvements in WFIRS-P Total and all domain scores were associated with symptomatic treatment response in the GXR all-active group. CONCLUSIONS: GXR treatment in children with ADHD was associated with reductions in WFIRS-P functional impairment scores compared with placebo, regardless of time of GXR administration. Changes in WFIRS-P scores were congruent with clinical response, as determined by both ADHD symptom reduction and CGI-I scores. CLINICALTRIALS. GOV IDENTIFIER: NCT00997984.

A Randomized, Placebo-Controlled Trial of Guanfacine Extended Release in Adolescents With Attention-Deficit/Hyperactivity Disorder.

OBJECTIVE: Despite the continuity of attention-deficit/hyperactivity disorder (ADHD) into adolescence, little is known regarding use of nonstimulants to treat ADHD in adolescents. This phase 3 trial evaluated the safety and efficacy of guanfacine extended release (GXR) in adolescents with ADHD. METHOD: This 13-week, multicenter, randomized, double-blind, placebo-controlled trial evaluated once-daily GXR (1-7 mg per day) in adolescents with ADHD aged 13 to 17 years. The primary endpoint was the change from baseline in the ADHD Rating Scale-IV (ADHD-RS-IV) total score; key secondary endpoints included scores from the Clinical Global Impressions-Severity of Illness (CGI-S), and Learning and School domain and Family domain scores from the Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P) at week 13. RESULTS: A total of 314 participants were randomized (GXR, n = 157; placebo, n = 157). The majority of participants received optimal doses of 3, 4, 5, or 6 mg (30 [22.9%], 26 [19.8%], 27 [20.6%], or 24 [18.3%] participants, respectively), with 46.5% of participants receiving an optimal dose above the currently approved maximum dose limit of 4 mg. Participants receiving GXR showed improvement in ADHD-RS-IV total score compared with placebo (least-squares mean score change, -24.55 [GXR] versus -18.53 [placebo]; effect size, 0.52; p <.001). More participants on GXR also showed significant improvement in CGI-S scores compared with placebo (50.6% versus 36.1%; p = .010). There was no statistically significant difference between treatments at week 13 in the 2 WFIRS-P domains. Most treatment-emergent adverse events were mild to moderate, with sedation-related events reported most commonly. CONCLUSION: GXR was associated with statistically significant improvements in ADHD symptoms in adolescents. GXR was well tolerated, with no new safety signals reported. CLINICAL TRIAL REGISTRATION INFORMATION: Dose-Optimization in Adolescents Aged 13-17 Diagnosed With Attention-Deficit/Hyperactivity Disorder (ADHD) Using Extended-Release Guanfacine HCl; http://ClinicalTrials.gov/; NCT01081132.

Efficacy and safety of extended-release guanfacine hydrochloride in children and adolescents with attention-deficit/hyperactivity disorder: a randomized, controlled, phase III trial.

Guanfacine extended-release (GXR), a selective α2A-adrenergic agonist, is a non-stimulant treatment for attention-deficit/hyperactivity disorder (ADHD). This study assessed the efficacy (symptoms and function) and safety of dose-optimized GXR compared with placebo in children and adolescents with ADHD. An atomoxetine (ATX) arm was included to provide reference data against placebo. Patients (6-17 years) were randomized at baseline to dose-optimized GXR (0.05-0.12mg/kg/day - 6-12 years: 1-4mg/day; 13-17 years: 1-7mg/day), ATX (10-100mg/day) or placebo for 4 or 7 weeks. The primary efficacy measure was change from baseline in ADHD Rating Scale version IV (ADHD-RS-IV). Key secondary measures were Clinical Global Impression-Improvement (CGI-I) and the Weiss Functional Impairment Rating Scale-Parent Report (WFIRS-P; learning and school, and family domains). Safety assessments included treatment-emergent adverse events (TEAEs), electrocardiograms and vital signs. A total of 272 (80.5%) patients from Europe, the USA and Canada completed the study. Significant differences were observed in least squares mean change from baseline in ADHD-RS-IV total score (placebo-adjusted differences) (GXR: [-8.9, p<0.001]; ATX: [-3.8, p<0.05]), the difference from placebo in the percentage of patients showing improvement (1 ['very much improved'] or 2 ['much improved']) for CGI-I (GXR: [23.7, p<0.001]; ATX: [12.1, p<0.05]), WFIRS-P learning and school domain (GXR: [-0.22, p<0.01]; ATX: [-0.16, p<0.05]) and WFIRS-P family domain (GXR: [-0.21, p<0.01]; ATX: [-0.09, p=0.242]). Most common TEAEs for GXR were somnolence, headache and fatigue; 70.1% of GXR subjects reported mild-to-moderate TEAEs. GXR was effective and well tolerated in children and adolescents with ADHD.

Efficacy of guanfacine extended release assessed during the morning, afternoon, and evening using a modified Conners' Parent Rating Scale-revised: Short Form.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of once-daily guanfacine extended release (GXR) monotherapy administered either in the morning or evening, using a modified Conners' Parent Rating Scale-Revised: Short Form (CPRS-R:S) assessed three times/day in children with attention-deficit/hyperactivity disorder (ADHD). METHODS: This multicenter, double-blind, placebo-controlled study randomized children 6-12 years of age with ADHD into three groups: GXR a.m. (GXR in the morning and placebo in the evening), GXR p.m. (placebo in the morning and GXR in the evening), or twice-daily placebo. The CPRS-R:S, administered in the morning, afternoon, and evening prior to each study visit, was a secondary measure of efficacy. RESULTS: A total of 333 subjects were included in the analysis population (GXR a.m., n=107; GXR p.m., n=114; placebo, n=112). At visit 10, last observation carried forward (LOCF), subjects receiving GXR demonstrated significantly greater improvement from baseline in the daily mean CPRS-R:S total score, as well as in each of the morning, afternoon, and evening CPRS-R:S assessments, compared with placebo, regardless of the time of GXR administration (p<0.001 vs. placebo for GXR a.m. and GXR p.m.). In addition, subjects receiving GXR showed significantly greater improvements from baseline in each subscale score (oppositional, cognitive problems/inattention, hyperactivity, and ADHD index) compared with those receiving placebo, regardless of time of administration (p<0.003 vs. placebo across all subscales for GXR a.m. and GXR p.m.). CONCLUSIONS: These results provide further support for the demonstrated efficacy of once-daily GXR in reducing ADHD symptoms, and demonstrate that response is consistent throughout the day regardless of the time of administration, with improvement seen in ratings of oppositional as well as of ADHD symptoms.

Maintenance of efficacy of lisdexamfetamine dimesylate in children and adolescents with attention-deficit/hyperactivity disorder: randomized-withdrawal study design.

OBJECTIVE: In this phase 3 extension study, the long-term maintenance of efficacy of lisdexamfetamine dimesylate (LDX) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) was evaluated using a randomized-withdrawal study design. METHOD: European and US patients (6-17 years; N = 276) with ADHD were entered into a 26-week open-label trial of LDX treatment. Those who completed the open-label period (n = 157) were randomized 1:1 to their optimized dose of LDX (30, 50, or 70 mg per day) or placebo for a 6-week randomized-withdrawal period (RWP). The primary efficacy measure was the proportion of patients meeting treatment failure criteria (≥50% increase in ADHD Rating Scale IV total score and ≥2-point increase in Clinical Global Impressions-Severity of Illness [CGI-S] score, compared with RWP start point). Safety and tolerability were also evaluated. RESULTS: During the RWP (LDX, n = 78; placebo, n = 79), significantly fewer patients receiving LDX met treatment failure criteria (15.8%) compared with those receiving placebo (67.5%; difference = -51.7%; 95% confidence interval = -65.0, -38.5; p < .001 ). Most treatment failures occurred at or before the week 2 visit after randomization. Treatment-emergent adverse events were reported in 39.7% and 25.3% of patients receiving LDX and placebo, respectively, during the RWP. CONCLUSIONS: These data demonstrate the maintenance of efficacy of LDX during long-term treatment in children and adolescents with ADHD. The rapid return of symptoms on LDX withdrawal demonstrates the need for continuing treatment. The safety profile of LDX was consistent with that of other stimulants. Clinical trial registration information-Double-Blind, Placebo-Controlled, Randomized Withdrawal, Extension, Safety and Efficacy Study of LDX in Children and Adolescents Aged 6-17; http://clinicaltrials.gov; NCT00784654.

Evolution of the magnetic field structure of the Crab pulsar.

Pulsars are highly magnetized rotating neutron stars and are well known for the stability of their signature pulse shapes, allowing high-precision studies of their rotation. However, during the past 22 years, the radio pulse profile of the Crab pulsar has shown a steady increase in the separation of the main pulse and interpulse components at 0.62° ± 0.03° per century. There are also secular changes in the relative strengths of several components of the profile. The changing component separation indicates that the axis of the dipolar magnetic field, embedded in the neutron star, is moving toward the stellar equator. This evolution of the magnetic field could explain why the pulsar does not spin down as expected from simple braking by a rotating dipolar magnetic field.

Efficacy and safety of lisdexamfetamine dimesylate and atomoxetine in the treatment of attention-deficit/hyperactivity disorder: a head-to-head, randomized, double-blind, phase IIIb study.

OBJECTIVES: The aim of this study was to compare the efficacy and safety of the prodrug psychostimulant lisdexamfetamine dimesylate (LDX) and the non-stimulant noradrenergic compound atomoxetine (ATX) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) who had previously responded inadequately to methylphenidate (MPH). METHODS: This 9-week, head-to-head, randomized, double-blind, active-controlled study (SPD489-317; ClinicalTrials.gov NCT01106430) enrolled patients (aged 6-17 years) with at least moderately symptomatic ADHD and an inadequate response to previous MPH therapy. Patients were randomized (1:1) to an optimized daily dose of LDX (30, 50 or 70 mg) or ATX (patients <70 kg, 0.5-1.2 mg/kg with total daily dose not to exceed 1.4 mg/kg; patients ≥70 kg, 40, 80 or 100 mg). The primary efficacy outcome was time (days) to first clinical response. Clinical response was defined as a Clinical Global Impressions-Improvement (CGI-I) score of 1 (very much improved) or 2 (much improved). Secondary efficacy outcomes included the proportion of responders at each study visit and the change from baseline in ADHD Rating Scale (ADHD-RS-IV) and CGI-Severity scores. Tolerability and safety were assessed by monitoring treatment-emergent adverse events (TEAEs), height and weight, vital signs and electrocardiogram parameters. Endpoint was defined as the last post-baseline, on-treatment visit with a valid assessment. RESULTS: Of 267 patients randomized (LDX, n = 133; ATX, n = 134), 200 (74.9%) completed the study. The median time to first clinical response [95% confidence interval (CI)] was significantly shorter for patients receiving LDX [12.0 days (8.0-16.0)] than for those receiving ATX [21.0 days (15.0-23.0)] (p = 0.001). By week 9, 81.7% (95% CI 75.0-88.5) of patients receiving LDX had responded to treatment compared with 63.6% (95% CI 55.4-71.8) of those receiving ATX (p = 0.001). Also by week 9, the difference between LDX and ATX in least-squares mean change from baseline (95% CI) was significant in favour of LDX for the ADHD-RS-IV total score [-6.5 (-9.3 to -3.6); p < 0.001; effect size 0.56], inattentiveness subscale score [-3.4 (-4.9 to -1.8); p < 0.001; effect size 0.53] and the hyperactivity/impulsivity subscale score [-3.2 (-4.6 to -1.7); p < 0.001; effect size 0.53]. TEAEs were reported by 71.9 and 70.9% of patients receiving LDX and ATX, respectively. At endpoint, both treatments were associated with mean (standard deviation) increases in systolic blood pressure [LDX, +0.7 mmHg (9.08); ATX, +0.6 mmHg (7.96)], diastolic blood pressure [LDX, +0.1 mmHg (8.33); ATX, +1.3 mmHg (8.24)] and pulse rate [LDX, +3.6 bpm (10.49); ATX, +3.7 bpm (10.75)], and decreases in weight [LDX, -1.30 kg (1.806); ATX, -0.15 kg (1.434)]. CONCLUSIONS: LDX was associated with a faster and more robust treatment response than ATX in children and adolescents with at least moderately symptomatic ADHD who had previously responded inadequately to MPH. Both treatments displayed safety profiles consistent with findings from previous clinical trials.

European, randomized, phase 3 study of lisdexamfetamine dimesylate in children and adolescents with attention-deficit/hyperactivity disorder.

This study evaluated the efficacy and safety of lisdexamfetamine dimesylate (LDX) compared with placebo in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) in Europe. Osmotic-release oral system methylphenidate (OROS-MPH) was included as a reference arm. Patients (6-17 years old) with a baseline ADHD Rating Scale version IV (ADHD-RS-IV) total score ≥ 28 were randomized (1:1:1) to dose-optimized LDX (30, 50, or 70 mg/day), OROS-MPH (18, 36, or 54 mg/day) or placebo for 7 weeks. Primary and key secondary efficacy measures were the investigator-rated ADHD-RS-IV and the Clinical Global Impressions-Improvement (CGI-I) rating, respectively. Safety assessments included treatment-emergent adverse events (TEAEs), electrocardiograms, and vital signs. Of 336 patients randomized, 196 completed the study. The difference between LDX and placebo in least squares mean change in ADHD-RS-IV total score from baseline to endpoint was -18.6 (95% confidence interval [CI]: -21.5 to -15.7) (p<0.001; effect size, 1.80). The difference between OROS-MPH and placebo in least squares mean change in ADHD-RS-IV total score from baseline to endpoint was -13.0 (95% CI: -15.9 to -10.2) (p<0.001; effect size, 1.26). The proportions (95% CI) of patients showing improvement (CGI-I of 1 or 2) at endpoint were 78% (70-86), 14% (8-21), and 61% (51-70) for LDX, placebo, and OROS-MPH. The most common TEAEs for LDX were decreased appetite, headache, and insomnia. Mean changes in vital signs were modest and consistent with the known profile of LDX. LDX was effective and generally well tolerated in children and adolescents with ADHD.

A controlled trial of extended-release guanfacine and psychostimulants for attention-deficit/hyperactivity disorder.

OBJECTIVE: To examine efficacy, tolerability, and safety of guanfacine extended release (GXR; ≤4 mg/d) adjunctive to a long-acting psychostimulant for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents 6 to 17 years of age with suboptimal, but partial, response to psychostimulant alone. METHOD: In this multicenter, 9-week, double-blind, placebo-controlled, dose-optimization study, subjects (N = 461) continued their stable dose of psychostimulant given in the morning and were randomized to receive GXR in the morning (GXR AM), GXR in the evening (GXR PM), or placebo. Efficacy measures included ADHD Rating Scale IV (ADHD-RS-IV) and Clinical Global Impressions of Severity of Illness (CGI-S) and Improvement (CGI-I) scales. Safety measures included adverse events (AEs), vital signs, electrocardiograms, and laboratory evaluations. RESULTS: At endpoint, GXR treatment groups showed significantly greater improvement from baseline ADHD-RS-IV total scores compared with placebo plus psychostimulant (GXR AM, p = .002; GXR PM, p < .001). Significant benefits of GXR treatment versus placebo plus psychostimulant were observed on the CGI-S (GXR AM, p = .013; GXR PM, p < .001) and CGI-I (GXR AM, p = .024; GXR PM, p = .003). At endpoint, small mean decreases in pulse, systolic, and diastolic blood pressure were observed in GXR treatment groups versus placebo plus psychostimulant. No new safety signals emerged following administration of GXR with psychostimulants versus psychostimulants alone. Most AEs were mild to moderate in severity. CONCLUSIONS: Morning or evening GXR administered adjunctively to a psychostimulant showed significantly greater improvement over placebo plus psychostimulant in ADHD symptoms and generated no new safety signals. Clinical trial registration information-Efficacy and Safety of SPD503 in Combination With Psychostimulants; http://www.clinicaltrials.gov; NCT00734578.

Psychomotor functioning and alertness with guanfacine extended release in subjects with attention-deficit/hyperactivity disorder.

OBJECTIVES: To determine whether treatment with guanfacine extended release (GXR) in subjects with attention-deficit/hyperactivity disorder (ADHD) disrupted psychomotor functioning and alertness, or impacted daytime sleepiness. METHOD: This was a randomized, double-blind, placebo-controlled, multicenter, phase 2, dose-optimization, noninferiority, laboratory classroom study of GXR (1, 2, and 3 mg/day) in 182 subjects aged 6 to 17 years with ADHD. Psychomotor functioning and alertness were assessed through several measures, including the Choice Reaction Time (CRT) test from the Cambridge Neuropsychological Test Automated Battery. Sedative effects were examined via spontaneously reported adverse events of sedation, somnolence, and hypersomnia as well as fatigue and lethargy, and with two validated subject- and observer-rated sleepiness scales. Standard efficacy measures for ADHD also were included. Cardiovascular and laboratory parameters were assessed. RESULTS: There were no significant differences between the GXR and placebo groups on measures of psychomotor functioning or alertness from the CRT at endpoint (least-square mean difference: 2.5 [95% confidence interval (CI): -22.9, 28.0], p = 0.8 for CRT; 2.5 [95% CI: -21.5, 26.4], p = 0.84 for correct responses; 15.5 [95% CI: -45.1, 14.1], p = 0.30 for movement time; and -8.2 [95% CI: -54.1, 37.6] p = 0.72 for total time). Most sedative adverse events were mild to moderate, occurred during dose titration, decreased with dose maintenance, and resolved during the study period. One subject in the GXR group discontinued due to fatigue and somnolence. GXR was not associated with increased daytime sleepiness. GXR treatment was associated with significant improvement in ADHD symptoms (6.3 [95% CI: 2.7, 9.8], p = 0.001 for ADHD Rating Scale IV total scores at endpoint). CONCLUSIONS: At doses that resulted in significant improvement in ADHD symptoms, impairment on cognitive tasks was not observed. Daytime sleepiness did not differ with GXR compared with placebo. Results suggest that the beneficial effects of GXR on ADHD symptoms are independent of sedation.

Effects of guanfacine extended release on oppositional symptoms in children aged 6-12 years with attention-deficit hyperactivity disorder and oppositional symptoms: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To evaluate the efficacy and safety of guanfacine extended release (XR, Intuniv; Shire Development Inc., Wayne, PA, USA) in the treatment of oppositional symptoms in children aged 6-12 years with a diagnosis of attention-deficit hyperactivity disorder (ADHD) and the presence of oppositional symptoms. SUBJECTS AND METHODS: In this randomized, double-blind, placebo-controlled, multicentre, flexible-dose, dose-optimization study, children aged 6-12 years were randomized to receive guanfacine XR (1-4 mg/day) or placebo for 9 weeks. Screening and washout periods were followed by a 5-week dose-optimization period, a 3-week dose-maintenance period and a 1-week tapering period. The primary efficacy measure was change from baseline to endpoint in the oppositional subscale of the Conners' Parent Rating Scale-Revised: Long Form (CPRS-R:L) score. Change in ADHD Rating Scale IV (ADHD-RS-IV) total score was a secondary efficacy measure. Safety assessments included adverse events (AEs), vital signs, ECG readings and laboratory studies. RESULTS: A total of 217 children were enrolled: 138 were randomized to receive guanfacine XR and 79 to receive placebo. Least-squares mean reductions from baseline to endpoint in CPRS-R:L oppositional subscale scores were 10.9 in the guanfacine XR group compared with 6.8 in the placebo group (p < 0.001; effect size = 0.59). A significantly greater reduction in ADHD-RS-IV total score from baseline to endpoint was also seen in the guanfacine-treated group compared with the placebo group (23.8 vs 11.5, respectively; p < 0.001; effect size = 0.92). A post hoc correlation analysis between percentage reduction from baseline to endpoint in CPRS-R:L oppositional subscale and ADHD-RS-IV total scores indicated that the decreases in oppositional symptoms and ADHD symptoms were highly correlated (r = 0.74). The most commonly reported, treatment-emergent AEs (TEAEs) in the guanfacine XR group were somnolence (50.7%), headache (22.1%), sedation (13.2%), upper abdominal pain (11.8%) and fatigue (11.0%) and most were mild or moderate in severity. TEAEs of sedation, somnolence or hypersomnia were experienced by 62.5% of subjects in the guanfacine XR group. These events were most common during the dose-titration period but most (63.5%) resolved prior to the taper period. TEAEs of fatigue, lethargy and asthenia were reported in 11.0%, 3.7% and 0.0% of subjects in the guanfacine XR group, respectively. Most subjects receiving guanfacine XR demonstrated modest changes in blood pressure, pulse rate and ECG readings that were not considered clinically significant. CONCLUSIONS: In this population of children aged 6-12 years with ADHD and the presence of oppositional symptoms, significant reductions in CPRS-R:L oppositional subscale and ADHD-RS-IV total scores were observed with guanfacine XR treatment compared with placebo. Treatment with guanfacine XR at optimized doses was associated with mostly mild or moderate TEAEs. The findings of this study support the efficacy of guanfacine XR in the treatment of children with ADHD and the presence of oppositional symptoms. CLINICAL TRIAL REGISTRATION NUMBER: NCT00367835.

Switched magnetospheric regulation of pulsar spin-down.

Pulsars are famed for their rotational clocklike stability and their highly repeatable pulse shapes. However, it has long been known that there are unexplained deviations (often termed timing noise) from the rate at which we predict these clocks should run. We show that timing behavior often results from two different spin-down rates. Pulsars switch abruptly between these states, often quasi-periodically, leading to the observed spin-down patterns. We show that for six pulsars the timing noise is correlated with changes in the pulse shape. Many pulsar phenomena, including mode changing, nulling, intermittency, pulse-shape variability, and timing noise, are therefore linked and are caused by changes in the pulsar's magnetosphere. We consider the possibility that high-precision monitoring of pulse profiles could lead to the formation of highly stable pulsar clocks.

Long-term safety and efficacy of guanfacine extended release in children and adolescents with attention-deficit/hyperactivity disorder.

OBJECTIVE: Short-term, controlled studies of extended-release guanfacine (GXR), a selective alpha(2A)-adrenoreceptor agonist, demonstrate efficacy in treating attention-deficit/hyperactivity disorder (ADHD) symptoms as monotherapy. This 2-year open-label study was conducted to further assess the long-term safety and efficacy of GXR. METHODS: Study participants, aged 6-17 years with ADHD, had previously been exposed to GXR therapy alone or in combination with psychostimulants in one of two antecedent trials. In this study, doses were titrated to 1, 2, 3, or 4 mg/day of GXR alone or in combination with a psychostimulant. Safety and efficacy data collected at clinic visits over 24 months provided further evidence of the overall safety and efficacy of GXR for treating ADHD. RESULTS: The majority of adverse events (AEs) were mild to moderate, and few patients discontinued the study because of an AE. Efficacy measures demonstrated significant improvement beginning in the first month and lasting through the end of the 24-month treatment period. Throughout the entire 2-year study, 202 subjects (77.1%) discontinued and 60 (22.9%) completed the study. CONCLUSIONS: Overall, these data support that GXR monotherapy is generally safe and effective for treating ADHD.

Guanfacine extended release in children and adolescents with attention-deficit/hyperactivity disorder: a placebo-controlled trial.

OBJECTIVE: This study compared the efficacy of guanfacine extended release (GXR), a selective alpha(2A)-adrenoceptor agonist, with placebo in children and adolescents with attention-deficit/hyperactivity disorder (ADHD). METHOD: This double-blind, 9-week, dose-ranging, parallel-design, multicenter trial randomized 6- to 17-year-olds with ADHD to once-daily oral GXR in 1-, 2-, 3-, and 4-mg doses or placebo. Primary outcome was change in total ADHD Rating Scale-IV score from baseline to endpoint. Secondary outcomes included changes in scores of hyperactive/impulsive and inattentive subscales; clinician and parent ratings; duration of clinical effect; and safety measures. RESULTS: Statistically significant reductions in ADHD Rating Scale-IV scores were observed from baseline to endpoint at all doses of GXR, with effect sizes ranging from 0.43 to 0.62. In subjects receiving GXR, mean heart rate and systolic and diastolic blood pressure decreased as the dose of GXR increased and then returned toward baseline during the dose-maintenance and dose-tapering phases of the trial. Most frequent treatment-emergent adverse events (> or = 5%) were somnolence, headache, fatigue, sedation, dizziness, irritability, upper abdominal pain, and nausea. Somnolence, sedation, and fatigue adverse events emerged within the first 2 weeks of dosing and generally resolved by study end. CONCLUSIONS: : Guanfacine extended-release was effective in reducing symptoms of ADHD. Adverse events were mild to moderate, did not interfere with improvements in attention, and rarely led to discontinuation.

A randomized, double-blind, placebo-controlled study of guanfacine extended release in children and adolescents with attention-deficit/hyperactivity disorder.

OBJECTIVE: With this study we assessed the efficacy and safety of an extended-release formulation of guanfacine compared with placebo for the treatment of children and adolescents with attention-deficit/hyperactivity disorder. METHODS: In this multicenter, double-blind, placebo-controlled, fixed-dosage escalation study, patients aged 6 to 17 years were randomly assigned to 1 of 3 treatment groups of guanfacine extended release (2, 3, or 4 mg/day) or placebo for 8 weeks. The primary outcome measurement was the Attention-Deficit/Hyperactivity Disorder Rating Scale IV total score. Secondary measurements included Clinical Global Impression of Improvement, Parent's Global Assessment, Conners' Parent Rating Scale-Revised: Short Form, and Conners' Teacher Rating Scale-Revised: Short Form. RESULTS: A total of 345 patients were randomly assigned to placebo (n = 86) or guanfacine extended release 2 mg (n = 87), 3 mg (n = 86), or 4 mg (n = 86) treatment groups. Least-squares mean changes from baseline to the end point in Attention-Deficit/Hyperactivity Disorder Rating Scale IV total scores were significant in all groups of children taking guanfacine extended release: -16.18 in the 2-mg group, -16.43 in the 3-mg group, and -18.87 in the 4-mg group, compared with -8.48 in the placebo group. All groups of children taking guanfacine extended release showed significant improvement on hyperactivity/impulsivity and inattentiveness subscales of the Attention-Deficit/Hyperactivity Disorder Rating Scale IV, Clinical Global Impression of Improvement, Parent's Global Assessment, Conners' Parent Rating Scale-Revised: Short Form, and Conners' Teacher Rating Scale-Revised: Short Form assessments compared with placebo. The most commonly reported treatment-emergent adverse events were headache, somnolence, fatigue, upper abdominal pain, and sedation. Small to modest changes in blood pressure, pulse rate, and electrocardiogram parameters were observed but were not clinically meaningful. CONCLUSIONS: Guanfacine extended release met the primary and secondary efficacy end points. It was well tolerated and effective compared with placebo.

Long-term, open-label extension study of guanfacine extended release in children and adolescents with ADHD.

INTRODUCTION: Guanfacine is a noradrenergic agonist that is believed to improve symptoms of attention-deficit/hyperactivity disorder (ADHD) through selective actions at alpha2A-adrenoceptors in the prefrontal cortex. A recent double-blind, multicenter trial supports the efficacy and safety of guanfacine extended release (GXR) for pediatric ADHD. This long-term, open-label extension was conducted to study the safety profile and effectiveness of GXR for up to 2 years. METHODS: Subjects were 240 children 6-17 years of age with a diagnosis of ADHD who participated in the preceding randomized trial. GXR was initiated at 2 mg/day and titrated as needed in 1-mg increments to a maximum of 4 mg/day to achieve optimal clinical response. RESULTS: The most common adverse events were somnolence (30.4%), headache (26.3%), fatigue (14.2%), and sedation (13.3%). Somnolence, sedation, and fatigue were usually transient. Cardiovascular-related adverse events were uncommon, although small reductions in mean blood pressure and pulse rate were evident at monthly visits. ADHD Rating Scale, Version IV, total and subscale scores improved significantly from baseline to endpoint for all dose groups (P<.001 for all comparisons, intent-to-treat population). CONCLUSION: Long-term treatment with GXR was generally safe for up to 24 months of treatment, and effectiveness was maintained over this treatment period.