Side effects
Side effects included nausea, vomiting, insomnia, loss of appetite, increased erythrocyte sedimentation, EKG and EEG anomalies, epigastric pain, diarrhea, constipation, vertigo, orthostatic hypotension, edema of the lower extremities, dysarthria, tremor, psychomotor agitation, mental confusion, inappropriate secretion of antidiuretic hormone, increased transaminases, seizure, (there were three cases worldwide, and most animal studies [and clinical trials that included epilepsy patients] indicated the presence of anticonvulsant properties, so was not completely contraindicated in epilepsy) and increased libido. Interactions
Viloxazine increased plasma levels of phenytoin by an average of 37%. It also was known to significantly increase plasma levels of theophylline and decrease its clearance from the body, sometimes resulting in accidental overdose of theophylline. Pharmacology
Pharmacodynamics
Viloxazine acts as a selective norepinephrine reuptake inhibitor and this is believed to be responsible for its therapeutic effectiveness in the treatment of conditions like ADHD and depression. The affinities (KD) of viloxazine at the human monoamine transporters are 155 to 630 nM for the norepinephrine transporter (NET), 17,300 nM for the serotonin transporter (SERT), and >100,000 nM for the dopamine transporter (DAT). Viloxazine has negligible affinity for a variety of assessed receptors, including the serotonin 5-HT1A and 5-HT2A receptors, the dopamine D2 receptor, the α1- and α2-adrenergic receptors, the histamine H1 receptor, and the muscarinic acetylcholine receptors (all >10,000 nM).More recent research has found that the pharmacodynamics of viloxazine may be more complex than previously assumed.
Medical uses
Attention deficit hyperactivity disorder
Viloxazine is indicated to treat attention deficit hyperactivity disorder (ADHD) in children age 6 to 12 years, adolescents age 13 to 17 years, and adults.In a phase 3 regulatory randomized controlled trial of viloxazine for ADHD in adults, scores on the Attention-Deficit/Hyperactivity Disorder Investigator Symptom Rating Scale (AISRS) with viloxazine therapy decreased from 38.5 points at baseline to 23.0 points following treatment (–40%) and with placebo decreased from 37.6 points at baseline to 25.9 points (–31%). This gave a placebo-subtracted score difference (drug minus placebo), or improvement in scores attributable to the effects of viloxazine, of –3.7 points (–9%). Depression
Viloxazine was previously marketed as an antidepressant for the treatment of major depressive disorder. It was considered to be effective in mild to moderate as well as severe depression with or without co-morbid symptoms. The typical dose range for depression was 100 to 400 mg per day in divided doses administered generally two to three times per day. Available forms
Viloxazine is available for ADHD in the form of 100, 150, and 200 mg extended-release capsules. These capsules can be opened and sprinkled into food for easier administration.