Atomoxetine Hydrochloride


Attentin (Atomoxetine) is indicated for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) as defined by DSM-IV criteria in children 6 years of age and older, adolescents and adults.


The precise mechanism by which Atomoxetine produces its therapeutic effects in Attention Deficit Hyperactivity Disorder (ADHD) is unknown. But, it is thought to be related to selective inhibition of the pre-synaptic nor-epinephrine transporter. Atomoxetine is well-absorbed after oral administration and is minimally affected by food. It is eliminated primarily by oxidative metabolism through the cytochrome P450 2D6 (CYP2D6) enzymatic pathway.

Dosage & Administration

Initial Treatment:
Children and Adolescents up to 70 kg Body Weight: Atomoxetine should be initiated at a total daily dose of approximately 0.5mg/kg and increased after a minimum of three days to a target total daily dose of approximately 1.2mg/kg administered either as a single daily dose in the morning or as evenly divided doses in the morning and late afternoon/early evening. After an additional two to four weeks, the total daily dose may be increased to a maximum of 1.4mg/kg in patients who have not achieved an optimal response. The maximum recommended total daily dose in children and adolescents is 1.4mg/kg or 100mg, whichever is less.

Children and Adolescents over 70 kg Body Weight and Adults: Atomoxetine should be initiated at a total daily dose of 40mg and increased after a minimum of three days to a target total daily dose of approximately 80mg administered either as a single daily dose in the morning or as evenly divided doses in the morning and late afternoon/early evening. After an additional two to four weeks, the dose may be increased to a maximum of 100mg in patients who have not achieved an optimal response. The maximum recommended total daily dose in children and adolescents over 70 kg is 100mg.

Maintenance/Extended Treatment: There is no evidence available from controlled trials to indicate how long the patient with ADHD should be treated with Atomoxetine. It is generally agreed, however, that pharmacological treatment of ADHD may be needed for extended periods. Nevertheless, the physician who elects to use Atomoxetine for extended periods should periodically re-evaluate the long-term usefulness of the medicine for the individual patient.

Pediatric use: The pharmacokinetics of Atomoxetine have not been evaluated in children under 6 years of age.


Slower titration of Atomoxetine may be necessary in those patients who are also taking CYP2D6 inhibitor medicines. Monoamine Oxidase Inhibitors- Atomoxetine should not be taken with monoamine oxidase inhibitors (MAOIs) or within two weeks after discontinuing MAOIs. Treatment with MAOIs should not be initiated within two weeks after discontinuing Atomoxetine. Anti-hypertensive drugs and Vasopressor Agents- Because of possible effects on blood pressure, Atomoxetine should be used cautiously with Anti-hypertensive drugs and vasopressor agents or other drugs that increase blood pressure. Tricyclic Antidepressants- Atomoxetine can increase the adverse cardiovascular effects of tricyclic antidepressants if co-administered.


Hypersensitivity: Atomoxetine is contra-indicated in patients with known hypersensitivity to it.

Monoamine Oxidase Inhibitors: Atomoxetine should not be taken with monoamine oxidase inhibitors (MAOIs) or within two weeks after discontinuing MAOIs. Treatment with MAOIs should not be initiated within two weeks after discontinuing Atomoxetine. With other medicines that affect brain monoamine concentrations, there have been reports of serious, sometimes fatal, reactions when taken in combination with MAOIs. These reactions include hyperthermia, rigidity, myoclonus, autonomic instability with possible rapid fluctuations of vital signs and mental status changes that include extreme agitation progressing to delirium and coma. Some cases presented with features resembling neuroleptic malignant syndrome. Such reactions may occur when these medicines are given concurrently or in close proximity.

Narrow Angle Glaucoma: In clinical studies, the use of Atomoxetine was associated with an increased risk of mydriasis and therefore not recommended in patients with narrow angle glaucoma.

Atomoxetine is contra-indicated in patients with: Severe Cardiovascular Disorders, symptomatic cardiovascular diseases, uncontrolled hyperthyroidism, phaeochromocytoma.

Side Effects

Very common: blood pressure increased, heart rate increased.
Common: abdominal pain, rash, dyspepsia, early morning awakening, ejaculation disorder, ejaculation failure, fatigue, lethargy, tachycardia, paraesthesia, chills.
Uncommon: peripheral coldness.

Pregnancy & Lactation

Pregnancy Category B3. No adequate and well-controlled studies have been conducted in pregnant women. Atomoxetine should not be used during pregnancy unless the potential benefit justifies the potential risk to the foetus. Lactation: Atomoxetine and/or its metabolites were excreted in the milk of rats. It is not known if Atomoxetine is excreted in human milk. Caution should be exercised if Atomoxetine is administered to a nursing woman.

Precautions & Warnings

Suicidal Ideation and Behaviour: Suicidal ideation (suicidal thoughts) was statistically more frequently observed in clinical trials among children and adolescents treated with Atomoxetine (5/1357; [0.37%]) compared to those treated with placebo (0/851; [0%]). There was one report of suicidal behaviour in a patient in this age group treated with Atomoxetine compared with no reports in patients treated with placebo.

Aggressive Behaviour or Hostility: Although there is no conclusive evidence that Atomoxetine causes aggressive behaviour or hostility, during clinical trials these events were more frequently observed in children and adolescents treated with Atomoxetine compared to those receiving placebo (overall risk ratio of 1.33- not statistically significant).

Seizures: The pre-clinical and clinical trial data for Atomoxetine do not suggest that Atomoxetine is proconvulsive. However, seizures have been very rarely reported in post-marketing spontaneous reports. Atomoxetine should be used with caution in patients with a history of seizures.

Cardiovascular Effects: Atomoxetine can affect heart rate and blood pressure. It is recommended that the heart rate and blood pressure be measured before treatment is started and periodically during treatment to detect possible clinically important increases. 

Overdose Effects

The most commonly reported gastrointestinal symptoms including somnolence, dizziness, tremor, and abnormal behaviour. Hyperactivity and agitation have also been reported. Signs and symptoms consistent with mild to moderate sympatheticnervous system activation (e.g. tachycardia, blood pressure increased, mydriasis, dry mouth) were also observed. Most events were mild to moderate. In some cases of overdose involving Atomoxetine, seizures and very rarely QT prolongation have been reported. There is limited clinical trial experience with Atomoxetine overdose. No fatal overdoses occurred in clinical trials.

Therapeutic Class

CNS stimulant drugs

Storage Conditions

Store in a cool and dry place, protected from light.

Available Brand Names