Atomoxetine

Atomoxetine is a prescription drug used for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD). The U.S Food and Drug Administration approve atomoxetine on November 26, 2002. Atomoxetine is marketed as Strattera by Eli Lilly.



Uses
Atomoxetine is a prescription drug used for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD).

How is Taken
Atomoxetine is available in 10, 18, 25, 40, 60, 80, and 100 mg oral capsules.

Dosing of children under 70 kg
Atomoxetine is started at a total daily dose of 0.5 mg/kg and increased after a minimum of 3 days to a target total daily dose of 1.2 mg/kg administered either as a single daily dose in the morning or as evenly divided doses in the morning and late afternoon/early evening.

The total daily dose in children and adolescents should not exceed 1.4 mg/kg or 100 mg, whichever is less.

Dosing of children over 70 kg
Atomoxetine is started at a daily dose of 40 mg and increased after a minimum of 3 days to a target total daily dose of approximately 80 mg given either as a single daily dose in the morning, or as evenly divided doses in the morning and late afternoon/early evening.

After 2-4 additional weeks, the dose may be increased to a maximum of 100 mg in people who have not achieved an optimal response.

How Works
The precise mechanism by which atomoxetine works is unknown, but it may be related to inhibition of the pre-synaptic norepinephrine transporter located on brain cells.

How the Body Affects
Atomoxetine is rapidly absorbed, with peak circulating levels reached approximately 1-2 hours after dosing.

Atomoxetine is metabolized primarily through the CYP2D6 enzymatic pathway in the liver. Using Strattera with potent inhibitors of CYP2D6, such as fluoxetine, paroxetine, or quinidine, results in a substantial increase in circulating levels.

Atomoxetine's metabolite is excreted mainly in the urine (>80% of the original dose) and to a lesser extent in the feces (<17% of the original dose).

Side Effects
The most frequent side effects in patients treated with Strattera were:


 * Abdominal pain
 * Vomiting
 * Nausea
 * Fatigue
 * Irritability
 * Weight loss
 * Loss of appetite
 * Headache
 * Sleepiness
 * Dizziness
 * Rash

Suicidal thoughts and actions in children and teenagers
Results from clinical studies with over 2200 ADHD patients suggest that some children may have a higher chance of having suicidal thoughts or actions. The chance for suicidal thoughts and actions may be higher early during treatment or during dose adjustments.

Severe liver damage
Atomoxetine can cause liver injury in some patients.

Heart-related problems
The following heart-related problems have been observed in patients treated with atomoxetine:


 * Sudden death in patients who have heart problems or heart defects
 * Stroke and heart attack in adults
 * Increased blood pressure and heart rate

Psychiatric problems in children and teenagers
New psychotic symptoms (such as hearing voices, believing things that are not true, being suspicious) or new manic symptoms (such as inflated self-esteem or grandiosity, decreased need for sleep, more talkative than usual, racing thoughts, overly distracted) may develop.

Monoamine Oxidase (MAO) Inhibitors
There have been reports of serious reactions (including severe fever, rigidity, rapid fluctuations of vital signs, and behavioral changes) when taken in combination with MAO inhibitors.

Pressor Agents
Because of possible effects on blood pressure, atomoxetine needs to be used cautiously with pressor agents (e.g., dopamine, dobutamine).

Albuterol
Atomoxetine needs to be administered with caution to patients being treated with oral or intravenous albuterol (or other drugs of the same class) because the action of albuterol on the heart can be strengthened, resulting in increased heart rate and blood pressure.

In children
In a study of 297 children aged 8 to 18, patients received either a fixed dose of atomoxetine (0.5, 1.2, or 1.8 mg/kg/day) or placebo. Atomoxetine was administered as a divided dose in the early morning and late afternoon/early evening.

At the two higher doses, improvements in ADHD symptoms were significantly superior in atomoxetine-treated patients compared with placebo-treated patients. The 1.8 mg/kg/day Strattera dose did not provide any additional benefit over that observed with the 1.2 mg/kg/day dose. The 0.5 mg/kg/day atomoxetine dose was not superior to placebo.

In adults
In two identical studies involving a combined 536 patients, patients received either Strattera or placebo.

In both studies, ADHD symptoms were significantly improved on atomoxetine.