Medication overuse in a subgroup analysis of phase 3 placebo-controlled studies of galcanezumab in the prevention of episodic and chronic migraine.

INTRODUCTION: Acute medication overuse is prevalent in patients with migraine. METHODS: In three phase 3, double-blind, randomized, placebo-controlled studies, patients with episodic migraine (EVOLVE-1 and EVOLVE-2) or chronic migraine (REGAIN) were randomized 2:1:1 to monthly subcutaneous injections of placebo or galcanezumab 120 or 240 mg for 3 or 6 months. This subgroup analysis evaluated mean changes in the number of monthly migraine headache days in each treatment among patients with versus without baseline acute medication overuse via mixing modelling with repeated measures. RESULTS: The percentages of patients with baseline medication overuse in placebo, galcanezumab 120-mg and 240-mg groups, respectively, were 19.4%, 17.3%, and 19.3% for EVOLVE-1/-2 (pooled; post hoc), and 63.4%, 64.3%, and 64.1% for REGAIN (a priori). Both galcanezumab doses demonstrated significant improvement compared with placebo for overall least squares mean change in monthly migraine headache days in patients with baseline medication overuse in both the episodic and chronic migraine studies (p ≤ 0.001). Furthermore, both galcanezumab doses reduced average monthly medication overuse rates compared to placebo (p < 0.001) in both patient populations with medication overuse at baseline. CONCLUSIONS: Galcanezumab appears to be effective for the preventive treatment of episodic and chronic migraine in patients who overuse acute medications.Trial registration: ClinicalTrials.gov Identifiers: NCT02614183, NCT02614196, and NCT02614261.

Migraine Headache Day Response Rates and the Implications to Patient Functioning: An Evaluation of 3 Randomized Phase 3 Clinical Trials of Galcanezumab in Patients With Migraine.

OBJECTIVE: This post hoc study investigated the relationship between patient response in terms of migraine headache day reduction and patient-reported outcomes of health-related quality of life (HRQoL) and disability categories. BACKGROUND: Migraine causes considerable disease-related disability and negatively impacts HRQoL of patients. Calcitonin gene-related peptide inhibitors improve these outcomes and may eliminate disability due to migraine in some patients. METHODS: Analyses used data from 3 double-blind, placebo (PBO)-controlled, phase 3 studies in adults with episodic migraine (EM) (EVOLVE-1: N = 858 and EVOLVE-2: N = 915) or chronic migraine (CM) (REGAIN: N = 1113). Patients were randomized 2:1:1 to subcutaneous injection of PBO, galcanezumab (GMB) 120 mg, or GMB 240 mg once monthly for 6 months in EVOLVE-1 and -2 and for 3 months in REGAIN. Primary endpoint was overall mean change from baseline in monthly migraine headache days. Patients were divided into 4 response-level groups based on percent change from baseline (<30%, ≥30% to <50%, ≥50% to <75%, ≥75%). Patient-reported outcomes included the 14-item Migraine-Specific Quality of Life Questionnaire version 2.1 (MSQ) and Migraine Disability Assessment (MIDAS) questionnaire. RESULTS: Among patients with migraine, mean improvements from baseline in MSQ domain scores increased with each successive level of migraine headache day response. On a 100-pt scale, increases in Role Function-Restrictive score in EM were 16.8 and 36.0 at the <30% and ≥75% response levels, respectively, and for CM were 10.7 and 46.5. Similar patterns in scores were observed for the Role Function-Preventive and Emotional Function domains. Examination of improvement in MSQ item score by treatment group showed that, in patients with EM, approximately 10 to 20% more GMB-treated patients (N = 796 for GMB 120 mg and GMB 240 mg) had improvements in all 14 MSQ items compared with PBO-treated patients (N = 773) (all P < .001). In patients with CM, 3 to 16% more GMB-treated patients (N = 507) had improvements in the 14 MSQ items compared with PBO (N = 494), though differences were statistically significant in only 19 of 28 comparisons. At baseline, mean MIDAS scores (EM, 33.1; CM, 67.2) indicated severe mean disability for patients with EM and very severe disability for patients with CM. Among patients with EM, 215 of 425 (50.6%) of those treated with GMB 120 mg and 212 of 413 (51.3%) treated with 240 mg had little/no disability due to migraine after 6 months (PBO: 277 of 832 (33.3%), P < .001 for both). Among patients with CM, 50 of 254 (19.7%) of those treated with GMB 120 mg and 54 of 258 (20.9%) treated with 240 mg reached the level of little/no disability after 3 months of treatment (PBO: 70 of 504 (13.9%), P = .045 for 120 mg, P = .017 for 240 mg). CONCLUSIONS: Because migraine greatly impairs an individual's ability to participate in activities of daily living, measurements of HRQoL are essential in clinical research. This study showed that function in daily life, as measured by MSQ score, improved as migraine headache days were reduced and that GMB-treated patients were more likely to see improvement in MSQ item scores compared with PBO-treated patients. Elimination of migraine-related disability was also more frequent in GMB-treated patients compared with placebo-treated patients.

Trajectory of migraine-related disability following long-term treatment with lasmiditan: results of the GLADIATOR study.

BACKGROUND: Migraine is recognized as the second leading cause of disability globally. Lasmiditan is a novel, selective serotonin 5-HT1F receptor agonist developed for acute treatment of migraine. Here we analyzed effects of lasmiditan on migraine disability assessed with the Migraine Disability Assessment (MIDAS) scale for interim data from a long-term safety study. METHODS: Completers of two single-attack parent studies were offered participation in the 1 year GLADIATOR study, that randomized participants to treatment with lasmiditan 100 mg or 200 mg taken as needed for migraine attacks of at least moderate severity. Changes in MIDAS were modeled using a mixed model repeated measures analysis. RESULTS: The sample included 1978 patients who received ≥1 lasmiditan dose and were followed for a median of 288 days. Baseline mean MIDAS scores for the lasmiditan 100-mg and 200-mg groups were 29.4 and 28.9, respectively, indicating severe migraine-related disability. Relative to baseline, MIDAS total scores were significantly lower at 3, 6, 9, and 12 months for both dose groups. At 12 months, changes in MIDAS scores were - 12.5 and - 12.2 for lasmiditan 100 mg and 200 mg, respectively, with 49% and 53% of patients, respectively, achieving at least a 50% decrease in MIDAS total score. Statistically significant improvements were also seen for work and/or school absenteeism and presenteeism, monthly headache days, and mean headache pain intensity at all time points up to 1 year. Findings for patients who completed all visits versus those dropping out early were similar. Responses were generally similar for the lasmiditan 100 mg or 200 mg doses, between subgroups defined based on the number of baseline monthly migraine attacks (≤5 vs. >5), and also between subgroups defined by pain-free response (yes/no) during initial attacks. CONCLUSIONS: Long-term treatment with lasmiditan was associated with significant reductions in migraine-related disability, including both work or school absenteeism and presenteeism. The similarity of responses in completers and those who dropped out suggests that selective attrition does not account for the improvements. Benefits were significant at 3 months and maintained through 12 months. TRIAL REGISTRATION: clinicaltrials.govNCT02565186; first posted October 1, 2015.

Efficacy of galcanezumab in patients with chronic migraine and a history of preventive treatment failure.

BACKGROUND: Efficacy of galcanezumab in chronic migraine has been demonstrated in a pivotal Phase 3 study. Here, we assess efficacy in patients who have failed ≥2 and ≥1 prior migraine preventives for efficacy and/or safety reasons, and in those who never failed. STUDY DESIGN/METHODS: REGAIN (NCT02614261) was a Phase 3, randomized, double-blind, placebo-controlled study in patients with chronic migraine. Patients were randomized 2:1:1 to receive placebo, galcanezumab 120 mg/240 mg once monthly during a double-blind treatment period lasting three months. Subgroup analyses were conducted among patients who failed ≥2 and ≥1 prior preventives and who never failed previously. Outcomes assessed were change from baseline in number of monthly migraine headache days, proportion of patients with ≥50% and ≥75% response (reduction in monthly migraine headache days), change in number of monthly migraine headache days with acute medication use and change in patient functioning per Migraine-Specific Quality of Life Questionnaire Role Function Restrictive (MSQ RF-R) domain score. RESULTS: Treatment with galcanezumab versus placebo resulted in significant improvements (p < 0.01) in overall reduction (Months 1-3) from baseline in the number of monthly migraine headache days in patients with prior failures (LS mean change [SE]: ≥2 prior failures: galcanezumab 120 mg: -5.35 (0.71); galcanezumab 240 mg: -2.77 (0.66); placebo: -1.01 (0.54); ≥1 prior failures: galcanezumab 120 mg: -5.53 (0.60), galcanezumab 240 mg: -3.53 (0.59); placebo: -2.02 (0.49). Similarly, significant results were seen with galcanezumab versus placebo for ≥50% and ≥75% response rates, reductions in acute medication use and improvements in MSQ RF-R domain score. In the subgroup with no prior preventive failures, results were statistically significant for the 240 mg galcanezumab group versus placebo on all outcome measures, and for the 120 mg group on the reduction in migraine headache days with acute medication use. There was also a higher placebo response observed in the patients with no prior preventive failures. CONCLUSION: Galcanezumab is consistently efficacious versus placebo in reducing monthly migraine headache days and several other key outcomes in patients with chronic migraine who have failed ≥2 or ≥1 preventives previously. In the subgroup with no prior failures, greater numerical differences were seen with galcanezumab, but statistical separation from placebo varied by dose and outcome. CLINICALTRIALS.GOV IDENTIFIER NUMBER: NCT02614261.

Patient satisfaction, health care resource utilization, and acute headache medication use with galcanezumab: results from a 12-month open-label study in patients with migraine.

BACKGROUND: Effects of galcanezumab, a monoclonal antibody against calcitonin gene-related peptide, on patient satisfaction, health care resource utilization (HCRU), and acute medication use were evaluated in a long-term, open-label study in patients with migraine. METHODS: Patients with episodic (78.9%) or chronic migraine (21.1%) were evaluated in the CGAJ study, an open-label study with 12-month treatment period. Galcanezumab 120 mg (with a loading dose of 240 mg) or 240 mg was administered subcutaneously once a month during treatment period. A self-rated scale, Patient Satisfaction with Medication Questionnaire-Modified (PSMQ-M), was used to measure satisfaction levels. Participants reported HCRU for the previous 6 months at baseline and that which occurred since the patient's last study visit during treatment period. Acute headache medication use for migraine or headache for the past month was self-reported by participants at baseline and at each monthly visit during treatment period. RESULTS: At Months 1, 6, and 12, at least 69% of patients treated with galcanezumab responded positively for overall satisfaction, preference over prior treatments, and less impact from side effects. There were within-group reductions from baseline in migraine-specific HCRU (per 100 person-years) with galcanezumab for health care professional visits (173.4 to 59.6), emergency room visits (20.2 to 4.7), and hospital admissions (3.7 to 0.4) during treatment period. Statistically significant reductions in HCRU were observed for some events. There were significant within-group reductions from baseline in mean number of days/month with acute headache medication use for migraine or headache at each monthly visit during treatment period (overall change: -5.1 for galcanezumab 120 mg/240 mg; p<0.001). CONCLUSION: Results from this long-term, open-label study suggest that treatment with galcanezumab is likely to lead to high patient satisfaction with treatment as well as meaningful reductions in migraine-specific HCRU and acute headache medication use in people with migraine.

A Pilot Study Using a Web Survey to Identify Characteristics That Influence Hypogonadal Men to Initiate Testosterone Replacement Therapy.

Men with hypogonadism (HG) who choose testosterone replacement therapy (TRT) may have distinct characteristics that provide insight as to why they may/may not initiate therapy. The aim of the current study was to identify trends in patient characteristics and attitudes in men diagnosed with HG who initiated TRT (TRT+) compared with men who were diagnosed with HG but did not initiate TRT (TRT-). The market research-based online survey conducted between 2012 and 2013 included patients from a Federated Sample, a commercially available panel of patients with diverse medical conditions. The current analysis was composed of two groups: TRT+ ( n = 155) and TRT- ( n = 157). Patient demographics, clinical characteristics, and attitudes toward HG and TRT were examined as potential predictors of primary adherence in men with HG; cohorts were compared by using Fisher's exact test. Significant associations among sexual orientation, relationship status, educational level, presence of comorbid erectile dysfunction, area of residence, and TRT initiation were present ( p ≤ .05). College-educated, heterosexual, married men with comorbid erectile dysfunction living in suburban and urban areas were more likely to initiate treatment. The most bothersome symptoms reported were lack of energy (90% vs. 81%, p = .075), decreased strength and endurance (86% vs. 76%, p = .077), and deterioration in work performance (52% vs. 31%, p = .004); lack of energy prompted men to seek help. Patients (48%) in the TRT+ group were more knowledgeable regarding HG as compared with TRT- respondents (14%, p < .001), and most men obtained their information from a health care professional (89% vs. 82%, p = .074). The current analysis identified distinct demographic and clinical characteristics and attitudes among TRT users compared with men who were diagnosed with HG yet remained untreated.

The Effect of Testosterone Topical Solution in Hypogonadal Men With Suboptimal Response to a Topical Testosterone Gel.

This study evaluated the effect of axillary administration of a 2% testosterone solution (Axiron®) in hypogonadal (HGN) men who had had a suboptimal response to treatment with a commercially available topical testosterone gel. HGN men averaging 57 years old, with a mean body mass index of 31.9 kg/m2 and median baseline testosterone level (T-level) of 185.2 ng/dL, who had failed to reach normal T-levels with a topical testosterone gel (Androgel 1.62%, Androgel, Testim, or Fortesta) were treated with a 2% testosterone solution until T-levels reached a normal range (from ≥300 to ≤1,050 ng/dL) or for up to 9 weeks. Outcomes included the cumulative percentage of men with a serum T-level in the normal range during treatment with Axiron and improvement in symptoms of low energy level and low sexual drive. During the study, 95% of HGN men (72/78) attained a T-level in the normal range. The median T-level at endpoint was 495.7 ng/dL, a threefold increase over baseline, p < .001, 70% achieving normal T-levels within the first 2 weeks of treatment. In a post hoc analysis, all subjects with baseline body mass indexes >35 kg/m2 ( n = 19) achieved T-levels in the normal range. Prior to treatment, over 61% of subjects (48/78) reported impairment in either energy level or sexual drive. After treatment (or testosterone normalization), energy level improved in 75% of subjects and sexual drive improved in 70%. Topical 2% testosterone solution is a safe and effective treatment for HGN men who have had a suboptimal response to previous treatment with topical testosterone gels.

Prospective Case-crossover Study Investigating the Possible Association Between Nonarteritic Anterior Ischemic Optic Neuropathy and Phosphodiesterase Type 5 Inhibitor Exposure.

OBJECTIVE: To evaluate the association between intermittent phosphodiesterase type 5 inhibitor (PDE5i) exposure and risk of acute nonarteritic anterior ischemic optic neuropathy (NAION) using a case-crossover design. METHODS: Male adults with suspected NAION were enrolled at 41 US ophthalmology sites from 2010 to 2015 and were interviewed regarding risk factors for NAION, medical history, and PDE5i use before NAION onset (index date of onset [IDO]). An adjudication committee confirmed the NAION cases. The primary analysis, using the person-time method, examined the rate of PDE5i exposure within 5 half-lives of NAION onset relative to PDE5i exposure over a 30-day study period preceding the IDO in men exposed to PDE5i intermittently as a measure of NAION risk associated with PDE5i exposure. Rate ratios were estimated using the Mantel-Haenszel estimator. Secondary analyses included person-time analyses over the 12-months preceding the IDO and matched-interval analyses over 42 days preceding the IDO. RESULTS: Of 279 men with confirmed NAION, 22 were exposed to PDE5i intermittently within 30 days of IDO. The Mantel-Haenszel rate ratio for risk of NAION associated with PDE5i exposure within 5 half-lives of IDO was 2.27 (95% confidence interval [CI]: 0.99-5.20) over the 30-day period (n = 22) and 3.52 (95% CI: 1.59-7.79) over the 12-month period (n = 26). Sensitivity analyses showed similar results and were statistically significant. The matched-interval method found no association (hazard ratio = 1.64 [95% CI: 0.60-4.51]). CONCLUSION: Overall, the study suggests an increased risk of NAION associated with PDE5i use. Patients and health-care providers should continue to weigh the risks and benefits of PDE5i use, including the potential for NAION.

Atomoxetine monotherapy compared with combination therapy for the treatment of ADHD: a retrospective chart review study.

OBJECTIVE: To analyze Clinical Global Impression-Severity (CGI-S) in ADHD patients treated with atomoxetine (ATX) monotherapy versus ATX combination therapy with another ADHD-indicated medication. METHODS: This was a 2-site retrospective observational chart review study of child and adult ADHD patients, not necessarily treatment naïve, but treated ≥50 days post baseline with an endpoint assessment. To adjust for measured confounders, monotherapy (n = 77) versus combination (n = 108) cohort comparisons were performed using propensity score stratification and adjusted ANCOVA. RESULTS: There were no significant baseline cohort differences after propensity stratification. CGI-S scores after a mean 264 days of treatment were not statistically significantly different between cohorts, with no cohort differences observed in any assessed symptom subcategory. The cohorts were similar in discontinuation due to any reason, adverse event, and lack of efficacy. CONCLUSION: ATX combination therapy showed no evidence of additional benefit over ATX monotherapy in the treatment of ADHD in a community-based setting.

Onset of response with duloxetine treatment in patients with osteoarthritis knee pain and chronic low back pain: a post hoc analysis of placebo-controlled trials.

BACKGROUND: Knowing when to change pain-medication strategy is not well researched and remains a gap in treating chronic pain. OBJECTIVE: Our aim was to determine how long to treat osteoarthritis (OA) knee pain and chronic low back pain (CLBP) with duloxetine before considering a change in medication strategy. METHODS: We employed a post hoc analysis of changes in pain-severity data from placebo-controlled studies of duloxetine treatment in nondepressed patients with OA knee pain and CLBP. The studies were selected for inclusion in the analyses based on similarity of study design. Pain severity was recorded daily in patient diaries using an ordinal 11-point numerical rating scale (0 = no pain to 10 = most severe pain). The weekly means of the daily 24-hour average pain severity ratings from these diaries were pooled within disease states. Moderate response was defined as at least a 30% reduction from baseline in pain severity, and minimal improvement was defined as <10% reduction from baseline. The probability of achieving at least moderate pain reduction during 3 months treatment with duloxetine was estimated by Kaplan-Meier methods in patients with no or minimal improvement after 2, 4, and 6 weeks of treatment, as well as in all patients who had not yet achieved a moderate response (<30% reduction in pain severity). RESULTS: There were 239 OA patients and 541 CLBP patients who were randomly assigned to treatment with duloxetine 60/120 mg/d. OA and CLBP patients with minimal improvement at 2 weeks of treatment had <40% probability of achieving a moderate response, and at 4 weeks of treatment their chances were reduced to <30% in OA patients and <25% in CLBP patients. In patients showing <30% improvement at week 2 of treatment, OA patients had a 62% probability of achieving a moderate response, and CLBP patients had a 52% probability for a moderate response, and at 4 weeks of treatment, their chances were reduced to <50% in OA patients and <40% in CLBP patients. CONCLUSIONS: Patients taking duloxetine for OA or CLBP who have <10% reduction in pain after 4 weeks of treatment have limited possibility for eventually achieving even moderate pain reduction by the end of 12 weeks. ClinicalTrials.gov identifier: NCT00433290, NCT00408421, NCT00424593, NCT00408876, NCT00767806.

Atomoxetine tolerability in pediatric and adult patients receiving different dosing strategies.

OBJECTIVE: Examine how different dosing schedules and recent stimulant therapy effect incidence, time to onset, and duration of common treatment-emergent adverse events (TEAEs) during atomoxetine treatment. METHOD: Post hoc analyses including safety data (open-ended questions) from 22 pediatric and 3 adult atomoxetine trials (1998-2009) in patients with attention-deficit/hyperactivity disorder. Most common TEAEs were determined by incidence rates and frequency of consumer and clinician inquiries. Onset and duration of TEAEs with slow versus fast titration, once-daily versus twice-daily dosing, and previous stimulant exposure were compared among treatment groups using Kaplan-Meier methods. RESULTS: In pediatric patients, the most commonly reported TEAEs were abdominal pain, decreased appetite, fatigue, nausea, somnolence, and vomiting; time to onset of TEAEs was significantly shorter for once-daily versus twice-daily dosing for all TEAEs (P ≤ .007) and for fast versus slow titration for abdominal pain, decreased appetite, and somnolence (all P values ≤ .009); duration of TEAEs with once-daily dosing was significantly longer for decreased appetite (P = .001) and nausea (P = .041); and more common in stimulant-naive patients versus patients with prior stimulant use were abdominal pain, decreased appetite, and fatigue (P ≤ .047). In adult patients, the most commonly reported TEAEs (erectile dysfunction data were excluded) were nausea, insomnia, decreased appetite, urinary hesitation/urinary retention, and fatigue; insomnia had a significantly shorter time to onset and longer duration with twice-daily versus once-daily dosing (P ≤ .032) and fast versus slow titration (P ≤ .007). CONCLUSIONS: Time to onset and resolution of TEAEs appear dependent on dosing schedule and titration speed. These findings can help to better manage tolerability issues and set appropriate expectations for clinicians and patients during atomoxetine titration, potentially improving treatment adherence and success.

Atomoxetine and osmotically released methylphenidate for the treatment of attention deficit hyperactivity disorder: acute comparison and differential response.

OBJECTIVE: Response to atomoxetine, a nonstimulant norepinephrine-specific reuptake inhibitor, was compared with the effect of osmotic-release oral methylphenidate, a long-acting methylphenidate preparation, in patients with attention deficit hyperactivity disorder (ADHD). METHOD: In a large placebo-controlled, double-blind study, patients ages 6-16 with ADHD, any subtype, were randomly assigned to receive 0.8-1.8 mg/kg per day of atomoxetine (N=222), 18-54 mg/day of osmotically released methylphenidate (N=220), or placebo (N=74) for 6 weeks. The a priori specified primary analysis compared response (at least 40% decrease in ADHD Rating Scale total score) to osmotically released methylphenidate with response to atomoxetine and placebo. After 6 weeks, patients treated with methylphenidate were switched to atomoxetine under double-blind conditions. RESULTS: The response rates for both atomoxetine (45%) and methylphenidate (56%) were markedly superior to that for placebo (24%), but the response to osmotically released methylphenidate was superior to that for atomoxetine. Each medication was well tolerated, with completion rates and discontinuations for adverse events not significantly different from those for placebo. Of the 70 subjects who did not respond to methylphenidate, 30 (43%) subsequently responded to atomoxetine. Likewise, 29 (42%) of the 69 patients who did not respond to atomoxetine had previously responded to osmotically released methylphenidate. CONCLUSION: Response was significantly greater with osmotically released methylphenidate than with atomoxetine. One-third of patients who received methylphenidate followed by atomoxetine responded better to one or the other, suggesting that there may be preferential responders.

Effects of atomoxetine on growth in children with attention-deficit/hyperactivity disorder following up to five years of treatment.

OBJECTIVE: To examine the effects on growth of long-term pharmacological treatment for attention-deficit/hyperactivity disorder (ADHD), we present findings from an ongoing 5-year study of the efficacy and safety of treatment with atomoxetine. METHODS: North American patients, 6-17 years old at study entry (N = 1,312) and with Diagnostic and Statistical Manual of Mental Disorders,4th edition (DSM-IV) ADHD, were studied under open-label atomoxetine treatment. Sixty-one were studied up to 5 years. RESULTS: After 1 month's treatment, patients weighed less than expected from their starting percentiles relative to population norms, with a maximum shortfall at 15 months and a return to expected weight by 36 months. Patients were slightly shorter than expected after 12 months, reaching a maximum shortfall at 18 months and returning to expected height by 24 months. Patients in the top quartile for body mass index (BMI) or weight at baseline, and those in the third quartile for height, showed 5-year decreases from expected values. Those below median height at baseline showed increases relative to expected values. CONCLUSIONS: These interim results indicate that continuous atomoxetine treatment for up to 5 years has little or no long-term effect on juvenile growth and final stature for most patients, although persistent decreases from expected may occur in some patients who are larger than average before treatment.

High-dose atomoxetine treatment of ADHD in youths with limited response to standard doses.

OBJECTIVE: To assess the utility and tolerability of higher than standard atomoxetine doses to treat attention-deficit/hyperactivity disorder (ADHD). METHOD: Two randomized, double-blind trials of atomoxetine nonresponders ages 6 to 16 years were conducted comparing continued treatment with same-dose atomoxetine to treatment using greater than standard efficacious doses (study 1: up to 3.0 mg . kg . day; study 2: up to 2.4 mg . kg . day). RESULTS: The primary outcome measure for both studies was mean ADHD Rating Scale (ADHD RS) total score. For study 1 (N = 122), decreases in ADHD RS total scores were not significantly different between treatment groups (mean change [SD]: continued same dose, -8.9 [11.2]; high dose, -9.8 [13.1]; p = .595). Likewise, for study 2 (N = 125), treatment groups did not differ (mean change [SD]: continued same dose, -6.2 [12.2]; high dose, -8.9 [10.0], p =.110). Tolerability was not significantly different between the continued same-dose and high-dose groups. CONCLUSIONS: These studies provide evidence that current dose recommendations are appropriate for most patients, suggesting no systematic advantage to increasing atomoxetine doses beyond current guidelines. In both studies, continued treatment, whether at a higher dose or the previous dose, was associated with improved outcomes in patients who demonstrated incomplete/inadequate response to acute ADHD treatment, although without a placebo arm, we cannot rule out the possibility that expectancy played a role in symptom improvement.

CYP2D6 and clinical response to atomoxetine in children and adolescents with ADHD.

BACKGROUND: Atomoxetine, a selective norepinephrine reuptake inhibitor effective in the treatment of attention-deficit/hyperactivity disorder (ADHD), is metabolized through the cytochrome P-450 2D6 (CYP2D6) enzyme pathway, which is genetically polymorphic in humans. Variations in plasma atomoxetine exposures can occur because of genetic variation or as a consequence of coadministration with drugs that inhibit CYP2D6. METHOD: We examined the effects of CYP2D6 on the efficacy, safety, and tolerability of atomoxetine in children and adolescents using pooled data from atomoxetine clinical trials. RESULTS: At endpoint, poor metabolizers had markedly greater reductions in mean symptom severity scores compared with extensive metabolizers (p < .05). Poor metabolizers had greater increases in heart rate and diastolic blood pressure (p < .001) and smaller increases in weight (p < .05) than extensive metabolizers. Several adverse events, including decreased appetite and tremor, were more frequent in poor metabolizers (p < .05). CONCLUSIONS: These results suggest that CYP2D6 poor metabolizers taking atomoxetine in doses up to 1.8 mg/kg/day are likely to have greater efficacy, greater increases in cardiovascular tone, and some differences in tolerability compared with CYP2D6 extensive metabolizers taking similar doses.

Low-dose atomoxetine for maintenance treatment of attention-deficit/hyperactivity disorder.

OBJECTIVE: Data from acute studies of atomoxetine in patients with attention-deficit/hyperactivity disorder suggest that a dose of approximately 1.2 mg/kg per day is required to attain a maximal symptom response. However, lower doses could be effective during maintenance treatment, which would reduce drug exposure and potential problems related to tolerability during chronic treatment. METHODS: Patients 6 to 16 years of age who had a robust response to an initial acute trial of atomoxetine were assigned randomly under double-blind conditions to continue treatment for up to 8 months with either the dose to which they had responded acutely (1.2-1.8 mg/kg per day, N = 116, continued same dose) or a lower dose (0.5 mg/kg per day, N = 113, low dose). The primary outcome measure was relapse, defined as an Attention-Deficit/Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator-Administered and Scored total score returned to > or = 90% of the original baseline value (before acute treatment) for 2 consecutive visits. Mean change in Attention-Deficit/Hyperactivity Disorder Rating Scale total score was assessed as a secondary outcome. RESULTS: At randomization, symptom severity was low and similar in both groups. At end point, relapse rates did not differ between the groups. Mean change in Attention-Deficit/Hyperactivity Disorder Rating Scale total score from the conclusion of acute treatment to end point also was not different between groups. Reports of affective lability were higher in the patients in the low-dose group. Also, increases in heart rate (compared with when atomoxetine was started) were higher in the patients in the continued same-dose group than in the low-dose group. Finally, increases in weight over the course of the trial were greater for the low-dose group than the continued same-dose group. CONCLUSIONS: For patients who experience a robust response to atomoxetine, it may be possible to retain the response during maintenance treatment with a reduced dose of atomoxetine.