Viloxazine: Uses and Applications
Viloxazine is primarily used for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) in children and adolescents aged 6 years and older. 1, 2
Mechanism of Action and Classification
- Viloxazine functions as a selective norepinephrine reuptake inhibitor (NRI) with additional activity in serotonergic pathways 1, 2
- The FDA states that while the exact mechanism for ADHD treatment is unclear, it is "thought to be through inhibiting the reuptake of norepinephrine" 1
- It has been classified as a "serotonin norepinephrine modulating agent" with serotonin modulation potentially being an important component of its therapeutic effect 3
Historical Context and Current Status
- Originally developed in the 1970s, viloxazine was used as an antidepressant in Europe for approximately 30 years 3, 4
- It was withdrawn from European markets in 2002 3
- Recently repurposed and developed in an extended-release formulation (Qelbree®) specifically for ADHD treatment 2, 4
- Received FDA approval in April 2021 for treating ADHD in pediatric patients aged 6-17 years 5
Clinical Applications
Primary Indication
- Treatment of ADHD in children and adolescents aged 6 years and older 1, 2
- Provides a non-stimulant alternative for ADHD management 2, 5
Historical Use
- Previously used in Europe as an antidepressant for treating depressive disorders 4, 6
- Was particularly noted for having fewer cardiovascular side effects compared to tricyclic antidepressants 4
Advantages as an ADHD Treatment
- Non-stimulant option with decreased risk of substance abuse and dependence compared to traditional stimulant medications 2, 5
- Useful alternative for patients who:
Dosing Considerations
- For ADHD treatment, the extended-release formulation is typically started at 200 mg once daily 3
- Can be titrated by 200 mg increments at weekly intervals based on response and tolerability 3
- Maximum daily dose is 600 mg/day 3, 1
Safety Profile
- Most common side effects include gastrointestinal symptoms 4
- The FDA drug label notes that viloxazine does not significantly prolong the QT interval at therapeutic doses 1
- Limited data is available regarding its use during pregnancy and breastfeeding, warranting caution in these populations 3
Clinical Considerations and Cautions
- Viloxazine is primarily metabolized by CYP2D6, UGT1A9, and UGT2B15 1
- Renal excretion is the primary elimination route, with 90% of the dose recovered in urine within 24 hours 1
- Dosage adjustments may be necessary for patients with hepatic or renal impairment 1
- Limited data is available on its efficacy and safety in adults with ADHD, though historically it was used in adults for depression 3, 4
Viloxazine represents an important addition to the non-stimulant options for ADHD treatment, offering an alternative for patients who cannot use or do not respond to stimulant medications.