by Adam Klapperich, DO

While the mainstay of pharmacologic ADHD treatment continues to be stimulant medication, there are non-stimulant options available such as Guanfacine, Clonidine, and Atomoxetine. Whereas the alpha-antagonists (guanfacine and clonidine) can be used as monotherapy or complementary with a stimulant), the norepinephrine reuptake inhibitor (NRI) Atomoxetine is typically used as monotherapy.

Atomoxetine (Strattera) was first approved in 2002 for ADHD treatment in children ages 6 and up, as well as adults. This NRI is most commonly used when stimulant medications are not tolerated or not effective. This medication is also an alternative to stimulants when abuse or diversion of stimulant medication is a consideration.

More recently, in 2021, Viloxazine (Qelbree) was approved for ADHD in children and adults. This NRI has similar mechanism of action, though there are some differences of which to take note. Firstly, according to the manufacturer of Qelbree, effects may be noticeable within 1-2 weeks, with continued improvement over several weeks. Strattera typically takes 3-6 weeks to become effective.

Both medications carry the FDA warning regarding risk of causing suicidal thoughts in children and young adults.

The main pharmacological difference is Qelbree has stronger secondary effects on serotonin signaling in the brain, which may contribute to possible additional therapeutic benefits for mood/anxiety. This same mechanism may contribute to a side effect not typically seen with Strattera, which is sleepiness/fatigue. Qelbree may be a better choice for those patients more susceptible to insomnia as a side effect.

Both medications are cytochrome 2D6 substrates, thus dose adjustments should be considered with know poor metabolizers at this cytochrome, or if concurrently using know 2D6 inhibitors such as fluoxetine or paroxetine. Additionally, Qelbree is a strong inhibitor of cytochrome 1A2.