What are the side effects of Qelbree (viloxazine)?

Side Effects of Qelbree (Viloxazine)

Qelbree (viloxazine) commonly causes somnolence, decreased appetite, fatigue, nausea, vomiting, insomnia, and irritability in pediatric patients, while adults most frequently experience insomnia, sleepiness, nausea, dry mouth, headache, tiredness, decreased appetite, and constipation. 1

Common Side Effects

In Children and Adolescents (6-17 years):

• Somnolence/sedation/lethargy: Occurs in 16% of patients (vs 4% with placebo) 1
• Decreased appetite: 7% (vs 0.4% with placebo) 1
• Fatigue: 6% (vs 2% with placebo) 1
• Nausea: 5% (vs 1% with placebo) 1
• Vomiting: 4% (vs 2% with placebo) 1
• Insomnia: 4% (vs 1% with placebo) 1
• Irritability: 3% (vs 1% with placebo) 1

In Adults:

• Insomnia: More common in adults than children 1
• Headache: 9% of patients 1, 2
• Somnolence: 6% (vs 2% with placebo) 1
• Fatigue: 12% (vs 3% with placebo) 1, 2
• Nausea: 10.1% 2
• Decreased appetite: 10.1% 2
• Dry mouth: 9% 2
• Constipation: Reported in adults 1

Serious Side Effects

Suicidal Thoughts and Behaviors

• Black box warning: Increased risk of suicidal thoughts or actions, especially within first few months of treatment or with dose changes 1
• Absolute risk difference of 0.7% compared to placebo 1
• Close monitoring recommended, especially during initial treatment period

Cardiovascular Effects

• Blood pressure and heart rate increases: Regular monitoring required 1
• May cause tachycardia in some patients

Psychiatric Effects

• Activation of mania/hypomania: Patients should be monitored for signs of activation 1
• Behavioral activation/agitation: May occur early in treatment or with dose increases

Other Serious Concerns

• Effects on weight: In short-term studies, children 6-11 years gained only 0.2 kg (vs 1 kg with placebo), while adolescents lost 0.2 kg (vs 1.5 kg gain with placebo) 1
• In long-term studies, the mean change in weight-for-age z-score was -0.2 at 12 months 1, 3

Discontinuation Rates Due to Side Effects

• Approximately 3% of pediatric patients discontinued due to adverse reactions 1
• Most common reasons: somnolence (n=5), nausea (n=3), headache (n=2), irritability (n=2), tachycardia (n=2), fatigue (n=2), and decreased appetite (n=2) 1
• In adults, approximately 9% discontinued due to adverse reactions 1, 2
• Most common reasons in adults: fatigue, insomnia, constipation, and headache 1

Long-Term Safety

In a long-term open-label extension trial with median exposure of 260 days 3:

• Most common adverse events (≥5%): nasopharyngitis (9.7%), somnolence (9.5%), headache (8.9%), decreased appetite (6.0%), and fatigue (5.7%)
• Most adverse events were mild to moderate in severity
• 8.2% of participants discontinued due to adverse events
• No new safety concerns emerged with long-term use

Important Precautions

• Driving and operating machinery: Patients should not perform activities requiring mental alertness until they know how they will be affected by Qelbree 1
• Concomitant medications: Avoid use with MAOIs and certain other medications (alosetron, duloxetine, ramelteon, tasimelteon, tizanidine, theophylline) 1
• Pregnancy: May cause harm to the mother; pregnancy registry available 1
• Breastfeeding: Passes into breastmilk; discuss risks and benefits 1

Monitoring Recommendations

1. Suicidal thoughts/behaviors: Close monitoring, especially during first few months and after dose changes
2. Blood pressure and heart rate: Regular monitoring throughout treatment
3. Weight: Monitor regularly, especially in pediatric patients
4. Mental status: Watch for signs of mania, hypomania, or behavioral activation
5. Somnolence: Assess impact on daily functioning and ability to operate machinery

Qelbree represents a non-stimulant option for ADHD treatment with a unique side effect profile that differs from both stimulants and other non-stimulants like atomoxetine and alpha-2 agonists.