Impact of Viloxazine Extended-Release Capsules (Qelbree®) on Select Cytochrome P450 Enzyme Activity and Evaluation of CYP2D6 Genetic Polymorphisms on Viloxazine Pharmacokinetics.

BACKGROUND AND OBJECTIVE: Viloxazine extended-release (ER) [Qelbree®] is a nonstimulant attention-deficit/hyperactivity disorder (ADHD) treatment. In vitro studies suggested potential for viloxazine to inhibit cytochrome 450 (CYP) enzymes 1A2, 2B6, 2D6 and 3A4. This clinical study therefore evaluated viloxazine ER effects on index substrates for CYP1A2, 2D6, and 3A4, and secondarily evaluated the impact of CYP2D6 polymorphisms on viloxazine pharmacokinetics. METHODS: Thirty-seven healthy subjects received a modified Cooperstown cocktail (MCC; caffeine 200 mg, dextromethorphan 30 mg, midazolam 0.025 mg/kg) on Day 1, viloxazine ER 900 mg/day on Days 3-5, and a combination of viloxazine ER 900 mg and MCC on Day 6. Viloxazine ER effects on MCC substrates were evaluated using analysis of variance. The impact of CYP2D6 genetic polymorphisms on steady-state viloxazine plasma concentrations was evaluated using Student's t test assessing pharmacokinetic parameter differences between poor versus extensive metabolizers. RESULTS: The least squares geometric mean ratio [GMR%] (90% CI) of MCC substrate + viloxazine ER/MCC substrate alone for caffeine maximum concentration (Cmax), area under the plasma concentration-time curve from time 0 to the last quantifiable concentration (AUCt), and area under the plasma concentration-time curve from time 0 extrapolated to infinity (AUC∞) was 99.11 (95.84-102.49), 436.15 (398.87-476.92), and 583.35 (262.41-1296.80), respectively; 150.76 (126.03-180.35), 185.76 (155.01-222.61), and 189.71 (160.37-224.42) for dextromethorphan Cmax, AUCt, and AUC∞, respectively; and 112.81 (104.71-121.54), 167.56 (153.05-183.45), and 168.91 (154.38-184.80) for midazolam Cmax, AUCt, and AUC∞, respectively. At steady state, viloxazine least squares GMR (90% CI) for poor/extensive CYP2D6 metabolizers were Cmax 120.70 (102.33-142.37) and area under the plasme concentration-time curve from time 0 to 24 hours (AUC0-24 125.66 (105.36-149.87)). CONCLUSION: Viloxazine ER is a strong CYP1A2 inhibitor and a weak CYP2D6 and CYP3A4 inhibitor. CYP2D6 polymorphisms did not meaningfully alter the viloxazine ER pharmacokinetic profile.

Impact of a High-Fat Meal and Sprinkled Administration on the Bioavailability and Pharmacokinetics of Viloxazine Extended-Release Capsules (QelbreeTM) in Healthy Adult Subjects.

BACKGROUND AND OBJECTIVES: Viloxazine extended-release (viloxazine ER) capsules (QelbreeTM) is a novel nonstimulant recently approved as a treatment for attention-deficit/hyperactivity disorder in children and adolescents. Here, we determined whether the pharmacokinetics of viloxazine are impacted by consuming the capsule contents sprinkled on applesauce rather than an intact capsule, and the effect of a high-fat meal on the pharmacokinetics of viloxazine ER. METHODS: This was a randomized, open-label, crossover, three-treatment, three-period study in healthy adults using orally administered single-dose viloxazine ER 200 mg capsules. Subjects consumed: (1) an intact capsule after a 10-h fast (control condition); (2) the capsule contents sprinkled on one tablespoon of applesauce; and (3) an intact capsule with a standard high-fat meal. Blood samples were collected for 48 h post-dosing. Relative bioavailability analyses were performed to assess the impact of each test condition against the control condition (intact capsule, fasting). The absence of an impact was indicated if the 90% confidence interval (CI) for the least-squares geometric mean ratio (LSGMR) of maximal concentration (Cmax), the area under the concentration-time curve from time 0 to the last measurable concentration time (AUClast), and the area under the concentration-time curve from time 0 to infinity (AUCinf) were within the predetermined no-difference limits of 80-125%. RESULTS: Out of 27 enrolled subjects, 25 were included in the pharmacokinetic analysis. The LSGMR (90% CI) for viloxazine ER sprinkled vs. intact were 90.10% (83.35-97.40) for Cmax, 93.71% (89.09-98.57) for AUClast, and 95.37% (89.80-101.28) for AUCinf. The LSGMR (90% CI) for viloxazine ER consumed in the fed state vs. fasting state were 90.86% (84.05-98.21) for Cmax, 89.68% (85.26-94.33) for AUClast, and 92.35% (86.96-98.07) for AUCinf. The 90% CIs of the LSGMRs were within the predetermined no-difference limits of 80-125%. Viloxazine ER was well tolerated, with most adverse events reported as mild. CONCLUSIONS: These data suggest that viloxazine ER can be consumed sprinkled on applesauce or as intact capsules with or without meals without significantly changing its pharmacokinetics.

Population Pharmacokinetics of Viloxazine Extended-Release Capsules in Pediatric Subjects With Attention Deficit/Hyperactivity Disorder.

Viloxazine extended-release capsules (viloxazine ER; Qelbree) is a novel nonstimulant, recently approved by the US Food and Drug Administration for the treatment of ADHD in pediatrics. Here, we characterize the pharmacokinetics (PK) of viloxazine and its major metabolite, 5-HVLX-gluc, using a population PK model and evaluate the impact of 1-4 days of missed viloxazine ER doses on viloxazine PK. Data from 4 phase 3 trials in pediatric subjects treated with viloxazine ER were used to establish the PK model. Covariate analysis was conducted on the final base model. The impact of 1-4 days of missed doses on steady-state viloxazine PK was evaluated using Monte Carlo simulations. A 1-compartmental linear model with first-order absorption and elimination of the parent drug and first-order metabolite formation and elimination properly described the population PK of viloxazine and 5-HVLX-gluc. Body weight impacted the systemic exposure of viloxazine and 5-HVLX-gluc. Predicted PK parameters at steady state (mean ± standard deviation) in children receiving viloxazine ER were determined. Cmax was 1.60 ± 0.70 µg/mL at 100 mg, 2.83 ± 1.31 µg/mL at 200 mg, and 5.61 ± 2.48 µg/mL at 400 mg. AUC0-t was 19.29 ± 8.88 µg·h/mL at 100 mg, 34.72 ± 16.53 µg·h/mL at 200 mg, and 68.00 ± 28.51 µg·h/mL at 400 mg. PK parameters for adolescents receiving viloxazine ER were also determined. Cmax was 2.06 ± 0.90 µg/mL at 200 mg, 4.08 ± 1.67 µg/mL at 400 mg, and 6.49 ± 2.87 µg/mL at 600 mg. AUC0-t was 25.78 ± 11.55 µg·h/mL at 200 mg, 50.80 ± 19.76 µg·h/mL at 400 mg, and 79.97 ± 36.91 µg·h/mL at 600 mg. Simulations revealed that, regardless of the duration of the dosing interruption, viloxazine concentration returned to steady-state levels after approximately 2 days of once-daily dosing of viloxazine ER.

A Phase 3, Placebo-Controlled Trial of Once-Daily Viloxazine Extended-Release Capsules in Adolescents With Attention-Deficit/Hyperactivity Disorder.

PURPOSE: This phase 3 clinical trial evaluated the efficacy and safety of viloxazine extended-release capsules (VLX-ER) as a monotherapy for attention-deficit/hyperactivity disorder (ADHD) in adolescents (12-17 years). METHODS: Eligible subjects (n = 310) were randomized to receive once-daily 200 and 400 mg VLX-ER, or placebo for 6 weeks. The primary efficacy end point was change from baseline (CFB) at the end of study (EOS) in ADHD Rating Scale-5 Total score. Key secondary end points were Clinical Global Impression-Improvement score at EOS, CFB at EOS in Conners 3-Parent Short Form Composite T-score, and CFB at EOS in Weiss Functional Impairment Rating Scale-Parent Total average score. RESULTS: In the 200-mg/d and 400-mg/d VLX-ER treatment groups, a significant improvement was found in the CFB at EOS in ADHD Rating Scale-5 Total (P = 0.0232, P = 0.0091) and Inattention (P = 0.0424, P = 0.0390) and Hyperactivity/Impulsivity (P = 0.0069, P = 0.0005) subscale scores versus placebo. The Clinical Global Impression-Improvement score was significantly improved at EOS in the 200-mg/d and 400-mg/d VLX-ER groups versus placebo (P = 0.0042, P = 0.0003). The Conners 3-Parent Short Form composite T-score and Weiss Functional Impairment Rating Scale-Parent Total average score exhibited improvement in both VLX-ER groups; however, the difference versus placebo was not statistically significant. The most common treatment-related adverse events were somnolence, headache, decreased appetite, nausea, and fatigue. The adverse event-related discontinuation rates were <5% in all groups. CONCLUSIONS: Viloxazine extended-release demonstrated statistically significant and clinically meaningful improvement in ADHD symptoms in adolescents and was generally well tolerated.

Viloxazine: Pediatric First Approval.

Viloxazine (QELBREE™), a selective norepinephrine reuptake inhibitor, is being developed by Supernus Pharmaceuticals as a non-stimulant for the treatment of attention-deficit/hyperactivity disorder (ADHD) in pediatric and adult patients. This is a novel formulation of a pharmacological agent formerly marketed in Europe for the treatment of depression in adults. Viloxazine received its first pediatric approval in April 2021 in the USA for the treatment of ADHD in pediatric patients aged 6-17 years. Approval was based on positive results from a series of short-term phase III clinical trials in which viloxazine improved the severity of ADHD symptoms in children and adolescents with diagnosed ADHD. Viloxazine is available as extended-release capsules for once-daily oral administration. This article summarizes the milestones in the development of viloxazine leading to this first pediatric approval for ADHD.

Viloxazine in the Management of CNS Disorders: A Historical Overview and Current Status.

Viloxazine has a long history of clinical use in Europe as an antidepressant, and has recently been repurposed into an extended-release form for the treatment of attention-deficit/hyperactivity disorder in the USA. An immediate-release formulation was approved for the treatment of depression in the UK in 1974, and was subsequently marketed there and in several European countries for 30 years with no major safety concerns. In contrast to first-generation antidepressants (e.g., tricyclic antidepressants, monoamine oxidase inhibitors), viloxazine was associated with a relatively low risk for cardiotoxicity. Gastrointestinal symptoms were the most commonly reported side effects. The therapeutic effects of viloxazine are thought to be primarily the result of its action as a norepinephrine reuptake inhibitor, although in vitro and preclinical in vivo animal data suggest that viloxazine may also impact the serotoninergic system. This review summarizes the evolving knowledge of viloxazine based on information from previously published preclinical and clinical investigations, and acquired unpublished historical study reports from both open-label and blinded controlled clinical trials. We review the chemical properties, mechanism of action, safety, and tolerability across these studies, and discuss the contemporary rationale for the development of this agent as an extended-release oral formulation for the treatment of attention-deficit/hyperactivity disorder.

Translating Attention-Deficit/Hyperactivity Disorder Rating Scale-5 and Weiss Functional Impairment Rating Scale-Parent Effectiveness Scores into Clinical Global Impressions Clinical Significance Levels in Four Randomized Clinical Trials of SPN-812 (Viloxazine Extended-Release) in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder.

Objectives: Clinical trials in psychiatry frequently report results from lengthy, comprehensive assessments to characterize a subject emotionally, cognitively, and behaviorally before and after treatment. However, the potential treatment implications of these results and how they translate into clinical practice remain unclear. Conversely, the Clinical Global Impressions (CGI) scales are quick, intuitive assessments used to assess the functional impact of a treatment in clinically relevant terms. The objectives of the present analyses are to translate scores from comprehensive assessments of symptom severity and functional impairment into clinically meaningful CGI levels. Methods: These post-hoc analyses use data integrated from four pivotal Phase 3 trials in attention-deficit/hyperactivity disorder (ADHD) in children and adolescents treated with the novel nonstimulant SPN-812 (Viloxazine Extended-Release). In this study, we evaluated the ADHD Rating Scale-5 (ADHD-RS-5) and Weiss Functional Impairment Rating Scale-Parent (WFIRS-P), assessments of symptom severity and functional impairment, respectively, by linking these scales with the CGI scales at baseline and end of study. Results: For participants that improved, a one-level change on the CGI-Improvement (CGI-I) was associated with a 10-15-point change on the ADHD-RS-5, and a 0.2-0.5-point change on the WFIRS-P. On the CGI-I, ratings of much improved and very much improved were associated with a percent score decrease (i.e., improvement) of ∼55% and 80% on the ADHD-RS-5 and ∼40% and 70% on the WFIRS-P, respectively. Differences between children and adolescents were minor and are unlikely to be clinically meaningful. Conclusion: These post-hoc analyses provide clinically meaningful benchmarks for the interpretation of scores on the ADHD-RS-5 and WFIRS-P in terms of CGI evaluations in subjects with ADHD. These results may be useful for physicians seeking to understand a treatment's potential impact on their ADHD patients or for researchers looking to define their study results within a clinically relevant context. Data are from clinical trials NCT03247530, NCT03247543, NCT03247517, and NCT03247556.

Pharmacokinetics of Coadministered Viloxazine Extended-Release (SPN-812) and Lisdexamfetamine in Healthy Adults.

BACKGROUND: Viloxazine extended-release is a novel nonstimulant under investigation as a potential treatment for attention-deficit/hyperactivity disorder (ADHD). Given the potential for viloxazine extended-release to be co-administered with stimulant ADHD pharmacotherapies, this trial investigated the pharmacokinetics and safety of combination viloxazine extended-release + lisdexamfetamine dimesylate (lisdexamfetamine) versus viloxazine extended-release and lisdexamfetamine alone. METHODS: In this single-center, cross-over, open-label trial, healthy, non-ADHD adults received single oral doses of 700 mg viloxazine extended-release alone, 50 mg lisdexamfetamine alone, and a combination of viloxazine extended-release (700 mg) + lisdexamfetamine (50 mg), with blood samples collected over 4 days postadministration. The active drug in viloxazine extended-release (viloxazine) and primary metabolite of lisdexamfetamine (d-amphetamine) were measured using chromatographic tandem mass spectrometry. Safety assessments included adverse events, vital signs, echocardiograms, and clinical laboratory evaluations. RESULTS: Thirty-six adults were enrolled, and 34 completed the trial. The least squares geometric mean ratios are reported as [combination / single drug (90% confidence intervals)]. Viloxazine extended-release: Cmax = 95.96% (91.33-100.82), area under the concentration-time curve from 0 to the last measurable time (AUC0-t) = 99.19% (96.53-101.91), and area under the concentration-time curve from 0 to infinity (AUCinf) = 99.23% (96.61-101.93). Lisdexamfetamine: Cmax = 112.78% (109.93-115.71), AUC0-t = 109.64% (105.25-114.22), and AUCinf = 109.52% (105.19-114.03). All reported adverse events, except 1 (moderate vomiting), were mild in severity. CONCLUSIONS: Co-administration of viloxazine extended-release and lisdexamfetamine did not impact the pharmacokinetics of viloxazine or d-amphetamine relative to administration of either drug alone. After single dose administration, the combination appeared to be safe and well tolerated.

Early response to SPN-812 (viloxazine extended-release) can predict efficacy outcome in pediatric subjects with ADHD: a machine learning post-hoc analysis of four randomized clinical trials.

Machine learning (ML) was used to determine whether early response can predict efficacy outcome in pediatric subjects with ADHD treated with SPN-812. We used data from four Phase 3 placebo-controlled trials of 100- to 600-mg/day SPN-812 (N=1397; 6-17 years of age). The treatment response was defined as having a ≥50% reduction in change from baseline (CFB) in ADHD Rating Scale-5 (ADHD-RS-5) Total score at Week 6. The variables used were: ADHD-RS-5 Total score, age, body weight, and body mass index at baseline; CFB ADHD-RS-5 Total score at Week 1, cumulative change in ADHD-RS-5 Total score at Week 2, and cumulative change in ADHD-RS-5 Total score at Week 3; Clinical Global Impressions-Improvement (CGI-I) score at Week 1, 2, and 3; and target dose. Using the best selected model, lasso regression, to generate importance scores, we found that change in ADHD-RS-5 Total score and CGI-I score were the best predictors of efficacy outcome. Change in ADHD-RS-5 Total score at Week 2 could predict treatment response at Week 6 (75% positive predictive power, 75% sensitivity, 74% specificity). Therefore, early response after two weeks of treatment with once-daily SPN-812 in pediatric patients with ADHD can predict efficacy outcome at Week 6.

Pharmacokinetics of Coadministered Viloxazine Extended-Release (SPN-812) and Methylphenidate in Healthy Adults.

BACKGROUND AND OBJECTIVES: Viloxazine extended-release (viloxazine ER, SPN-812) is a novel non-stimulant with activity at serotonin receptors and the norepinephrine transporter, which is under investigation as a potential treatment for attention-deficit/hyperactivity disorder. Given the potential for viloxazine ER to be coadministered with other pharmacotherapies, this trial investigated the pharmacokinetics and safety of combination viloxazine ER + methylphenidate versus viloxazine ER or methylphenidate alone. METHODS: In this single-center, crossover, open-label trial, healthy adult participants received oral administration of 700 mg viloxazine ER alone, 36 mg methylphenidate alone, and combination viloxazine ER (700 mg) + methylphenidate (36 mg), with blood samples collected over 4 days post-administration. The active drug in viloxazine ER (viloxazine) and methylphenidate was measured using chromatographic tandem mass spectrometry. Safety assessments included adverse events (AEs), vital signs, echocardiograms, and clinical laboratory evaluations. RESULTS: Of 36 healthy adults who were enrolled, 34 completed the trial. The geometric least squares mean ratios are reported as [combination/single drug (90% confidence intervals)]. For viloxazine ER, maximum measured plasma concentration (Cmax) = 100.98% (96.21-105.99), area under the concentration-time curve from time zero to the last measurable time (AUCt) = 98.62% (96.21-101.08), and area under the concentration-time curve from time zero to infinity (AUC∞) = 98.96% (96.55-101.44). For methylphenidate, Cmax = 103.55% (97.42-110.07), AUCt = 106.67% (101.01-112.64), and AUC∞ = 106.61% (100.99-112.54). All reported AEs were mild in severity. CONCLUSIONS: Coadministration of viloxazine ER and methylphenidate did not impact the pharmacokinetics of viloxazine or methylphenidate relative to administration of either drug alone. The combination appeared to be safe and well tolerated.

Evaluation of the Effect of SPN-812 (Viloxazine Extended-Release) on QTc Interval in Healthy Adults.

OBJECTIVE: To assess the effects of a supratherapeutic dose of SPN-812, a drug currently under investigation as a treatment for attention-deficit/hyperactivity disorder, on cardiac repolarization (QTc) in healthy adults. METHODS: The study was conducted from June 27, 2018, to July 10, 2018. It had a double-blind, randomized, crossover design in which subjects received a 3-treatment sequence-placebo, 400 mg moxifloxacin, and 1,800 mg SPN-812 for 2 consecutive days (separated by at least a 3-day washout). The primary endpoint was the correlation between the change from baseline (CFB) in individual heart rate corrected QT interval (QTcI) (ΔQTcI) and viloxazine and 5-hydroxyviloxazine glucuronide (5-OH-VLX-gluc) plasma concentrations (Cps). The secondary endpoint was the time point placebo-adjusted CFB in QTcI (ΔΔQTcI) for viloxazine. For assay sensitivity, the correlations between moxifloxacin Cp and the ΔQTcI, and moxifloxacin and time point ΔΔQTcI were evaluated. Additional evaluations included Fridericia's formula QT correction, heart rate, and the PR and QRS intervals. Changes in electrocardiogram (ECG) morphology along with other safety parameters were also analyzed and reported. RESULTS: The correlation between ΔQTcI and viloxazine Cp demonstrated a statistically significant negative slope (P = .0012). 5-OH-VLX-gluc Cp and ΔQTcI also demonstrated a statistically significant negative slope (P = .0007). Secondary time point analyses showed no effect of SPN-812 on QTcI. Assay sensitivity with moxifloxacin was confirmed. Safety parameters were acceptable. CONCLUSIONS: This study demonstrated that SPN-812 had no effect on cardiac repolarization or other ECG parameters in healthy adults, suggesting that it is not associated with a risk for cardiac arrhythmias or other electrocardiographic parameters.

A Phase III, Randomized, Placebo-controlled Trial to Assess the Efficacy and Safety of Once-daily SPN-812 (Viloxazine Extended-release) in the Treatment of Attention-deficit/Hyperactivity Disorder in School-age Children.

PURPOSE: The limitations of current US Food and Drug Administration (FDA)-approved medications for the treatment of attention-deficit/hyperactivity disorder (ADHD) set the need for the development of novel, effective, and tolerable medications to treat this disorder. The purpose of this study was to evaluate whether treatment with SPN-812 (viloxazine extended-release) significantly reduces symptoms of ADHD in children. METHODS: This study was a randomized, double-blind, placebo-controlled 6-week trial to assess the efficacy and safety of once-daily 100- and 200-mg SPN-812 in the treatment of ADHD in male and female children 6-11 years of age. Inclusion criteria required subjects to have a confirmed Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, ADHD diagnosis, an ADHD-Rating Scale-5 (ADHD-RS-5) score ≥28, a Clinical Global Impression-Severity score ≥4, and for subjects to be free of ADHD medication ≥1 week before randomization. The primary efficacy endpoint was the change from baseline (CFB) at end of study (EOS) in ADHD-RS-5 Total score. Key secondary endpoints included Clinical Global Impression-Improvement (CGI-I) scores at EOS and CFB at EOS in the Conners 3-Parent Short Form (Conners 3-PS) Composite T-score and the Weiss Functional Impairment Rating Scale-Parent (WFIRS-P) Total average score. Safety assessments included adverse events (AEs), laboratory tests, vital signs, physical examinations, ECGs, and the Columbia-Suicide Severity Rating Scale. The primary efficacy endpoint was analyzed by using a mixed model for repeated measures; all secondary measures were analyzed by using an ANCOVA model. RESULTS: A total of 477 subjects were randomized to treatment (intent-to-treat population, n = 460). The majority of subjects were male (63%) and either White (51.3%) or African American (43.7%). The demographic and baseline characteristics between the groups were similar. Statistically significant improvements in ADHD-RS-5 Total score were observed in both the 100- and 200-mg/day SPN-812 treatment groups compared to placebo at week 1 of treatment (P = 0.0004 and P = 0.0244, respectively), which was maintained through EOS (P = 0.0004 and P < 0.0001). Significant improvements were also observed at EOS in the CGI-I scale (P = 0.0020 and P < 0.0001), Conners 3-PS Composite T-score (P = 0.0003 and P = 0.0002), and WFIRS-P Total average score (P = 0.0019 and P = 0.0002) versus placebo. Treatment-related AEs reported in ≥5% of subjects included somnolence, decreased appetite, and headache. The discontinuation rate due to AEs was <5%. IMPLICATIONS: SPN-812 significantly reduced ADHD symptoms in children and was well tolerated. SPN-812 may prove to be an effective treatment for children with ADHD. ClinicalTrials.gov identifier: NCT03247530.

Citalopram and viloxazine in the treatment of depression by means of slow drop infusion. A double-blind comparative trial.

Antidepressant efficacy and tolerability of citalopram and viloxazine were compared under double-blind conditions during the first two weeks of treatment with slow drop infusion, followed by oral administration for the rest of the six week trial period. The 62 severely depressed and hospitalised patients included in the intention-to-treat analysis had a mean age of 45 years (range 23 to 70 years). About two thirds of the patients were female. Thirty patients were allocated to the citalopram and 32 patients to the viloxazine group. The mean MADRS total score at baseline was 34 in both groups and decreased to 12.3 in the citalopram and to 16.9 in the viloxazine group after 14 days of infusion. On day 42 (end point) the scores dropped to 6.7 in the citalopram and to 13.1 in the viloxazine group respectively. The group differences reached the level of significance at both time points (p < 0.05) in favour of citalopram. The analysis of treatment emergent adverse events based on the UKU scale showed a higher frequency of nausea on day 14 and constipation at study end in the viloxazine group (p < 0.05) whereas reported weight gain (day 21) and concentration difficulty (day 21) were more frequently seen in the citalopram group (p < 0.05). Standard laboratory investigations and ECG analyses did not show clinically relevant abnormalities. It is concluded that antidepressant treatment with citalopram infusion followed by oral citalopram may be more efficacious than a corresponding treatment schedule with viloxazine.

Cholinergic neurotransmission seems not to be involved in depression but possibly in personality.

Concordant with the adrenergic-cholinergic imbalance hypothesis of affective psychosis, there is a cholinergic supersensitivity in depression. Thus, the anticholinergic properties of some antidepressants might contribute to their efficacy. However, in the present double-blind studies (n = 20) with mianserin and viloxazine, respectively, which lack anticholinergic properties, adjunctive treatment with the anticholinergic biperiden versus placebo did not enhance the antidepressive efficacy. Therefore, we hypothesized that cholinergic supersensitivity might be linked to some possibly predisposing dimension of personality. Indeed, in healthy male volunteers (n = 11) the behavioral and cardiovascular sensitivity to physostigmine correlated significantly with "irritability" and "emotional lability" as well as with habitually passive strategies in stress coping. The rise in plasma cortisol and norepinephrine correlated with "retardation"; that of epinephrine with active coping. Thus, the cholinergic supersensitivity in affective psychoses might be linked to a personality dimension like stress sensitivity rather than to the diagnostic category itself.

Effects of administration route on pharmacokinetics of viloxazine in the rabbit.

The absorption of viloxazine chlorhydrate was investigated in ten rabbits. Each animal received the drug (15 mg/kg) by three routes: intravenous, gastric and duodenal. Viloxazine plasma concentrations were low when administered by gastric and duodenal routes compared to those after intravenous injection. Concentrations to peak were 1-2 times higher after duodenal than gastric administration. Times to peak were 23.0 +/- 4.7 min after gastric administration and 9.5 +/- 5.4 min after duodenal administration. A better absorption of viloxazine after administration occurred in the duodenum than in the stomach; these results agree with viloxazine pKa = 8.13. The other pharmacokinetic parameters such as half-life, clearance and volume of distribution where the same irregardless of the administration route.

[The use of viloxazine in the treatment of primary enuresis]. / L'utilisation de la Viloxazine dans le traitement de l'énurésie primaire.

The use of Viloxazine (a non tricyclic antidepressant) could be a less toxic alternative to Imipramine (cardiotoxic tricyclic antidepressant) in the treatment of childhood primary enuresis. Bladder overactivity, infection or psychological disturbances should be excluded before start of treatment, the drug seems to have a good efficacy in cases of "heavy sleepers".

[Clinical pharmacokinetics of viloxazine chlorhydrate. Practical implications]. / Pharmacocinétique clinique du chlorhydrate de viloxazine. Implications pratiques.

Pharmacokinetic data of an antidepressant agent: Apparent half-life (T1/2 elim), time of peak plasma concentration (Tmax), bioavailability, have a major contribution to determine optimal dosage in accordance with a low modification of steady-state levels. Viloxazine is a second generation antidepressant drug with a short apparent half-life (T1/2 elim: 2 to 5 h (3.4 h), which requires once a day 3 h i.v. infusion or three intakes of 100 mg oral standard formulation. The recent development of a new 300 mg slow-release form seems justified by a best compliance. Pharmacokinetic properties [Tmax = 3 to 9 h (5.2 h), T1/2 term = 6 to 7 h], suggest once a day dosage without risk of accumulation in chronic treatment. The relationships between plasma levels and the clinical improvement were not clear in literature. The recent therapeutic use of a 300 mg slow-release tablet has not permitted to change precedent findings.

Comparative pharmacokinetic study of conventional and sustained-release viloxazine in normal volunteers.

Animal and human studies have indicated that viloxazine hydrochloride, an antidepressant drug with a half-life of 3-4 h in most subjects at low dosage, is rapidly and almost completely absorbed after oral administration. A sustained-release form might be useful to decrease the frequency of administration. In our study, the pharmacokinetics of sustained-release form containing 300 mg viloxazine were compared with 300 mg conventional viloxazine in 11 normal volunteers (6 women, 5 men). Wide interindividual variations were observed with respect to plasma levels, but there was no significant statistical correlation between weight and blood concentration (conventional form: Cmax = 3,599 +/- 579 ng/ml, tmax = 86 +/- 26 min; sustained-release form: Cmax = 1,917 +/- 922 ng/ml, tmax = 215 +/- 77 min). Twelve hours after administration, plasma levels ranged between 540 and 1,600 ng/ml for the conventional form and between 660 and 2,120 ng/ml for the sustained-release form. Despite the great interindividual variation this new viloxazine form appears to be of interest for one daily administration.