Atomoxetine is a selective norepinephrine (NE) reuptake inhibitor used for the treatment of attention deficit hyperactivity disorder (ADHD). Also known as the marketed product Strattera, atomoxetine is used with other treatment modalities (psychological, educational, cognitive behaviour therapy, etc) to improve developmentally inappropriate symptoms associated with ADHD including distractibility, short attention span, hyperactivity, emotional lability, and impulsivity.
Atomoxetine has been shown to specifically increase NA and DA within the prefrontal cortex, but not in the nucleus accumbens (NA) or striatum.8 This is beneficial in the treatment of ADHD as DA activation in the subcortical NA and striatum is associated with many stimulant-associated side effects and an increase in abuse potential, which is a limiting factor associated with the use of stimulant medications such as Methylphenidate, Dextroamphetamine, and Lisdexamfetamine.
Atomoxetine is indicated for the treatment of attention deficit hyperactivity disorder (ADHD) in children and adults.
Atomoxetine is a selective norepinephrine (NE) reuptake inhibitor used for the treatment of attention deficit hyperactivity disorder (ADHD). Atomoxetine has been shown to specifically increase norepinephrine and dopamine within the prefrontal cortex, which results in improved ADHD symptoms.
In general, particular care should be taken in treating ADHD in patients with comorbid bipolar disorder because of concern for possible induction of a mixed/manic episode in patients at risk for bipolar disorder.
Treatment emergent psychotic or manic symptoms, e.g., hallucinations, delusional thinking, or mania in children and adolescents without a prior history of psychotic illness or mania can be caused by atomoxetine at usual doses. If such symptoms occur, consideration should be given to a possible causal role of atomoxetine, and discontinuation of treatment should be considered.
Atomoxetine is known to be a potent and selective inhibitor of the norepinephrine transporter (NET),2 which prevents cellular reuptake of norepinephrine throughout the brain, which is thought to improve the symptoms of ADHD.
More recently, positron emission tomography (PET) imaging studies in rhesus monkeys have shown that atomoxetine also binds to the serotonin transporter (SERT), and blocks the N-methyl-d-aspartate (NMDA) receptor, indicating a role for the glutamatergic system in the pathophysiology of ADHD.
Metabolism: Atomoxetine undergoes biotransformation primarily through the cytochrome P450 2D6 (CYP2D6) enzymatic pathway. People with reduced activity in the CYP2D6 pathway (also known as poor metabolizers or PMs) have higher plasma concentrations of atomoxetine compared with people with normal activity (also known as extensive metabolizers, or EMs). For PMs, the AUC of atomoxetine at steady-state is approximately 10-fold higher and Cmax is about 5-fold greater than for EMs.
Absorption: Atomoxetine is rapidly absorbed after oral administration, with absolute bioavailability of about 63% in extensive metabolizers (EMs) and 94% in poor metabolizers (PMs). Mean maximal plasma concentrations (Cmax) are reached approximately 1 to 2 hours after dosing with a maximal concentration of 350 ng/ml with an AUC of 2 mcg.h/ml.
Route of elimination: Atomoxetine is excreted primarily as 4-hydroxyatomoxetine-O-glucuronide, mainly in the urine (greater than 80% of the dose) and to a lesser extent in the feces (less than 17% of the dose). Only a small fraction (less than 3%) of the atomoxetine dose is excreted as unchanged atomoxetine, indicating extensive biotransformation.
Half life: The reported half-life depends on the CYP2D6 genetic polymorphisms of the individual and can range from 3 to 5.6 hours.
All medicines may cause side effects, but many people have no, or minor, side effects. Some medical conditions may interact with Atomoxetine.
Tell your doctor or pharmacist if you have any medical conditions.
The most commonly reported symptoms accompanying acute and chronic overdoses of atomoxetine capsules were gastrointestinal symptoms, somnolence, dizziness, tremor, and abnormal behavior. Hyperactivity and agitation have also been reported.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.
