Atomoxetine Hydrochloride

Atomoxetine Hydrochloride is a selective norepinephrine reuptake inhibitor (NRI) used for the treatment of ADHD [citation:1][citation:2]. It works by increasing the level of norepinephrine in the brain, which helps regulate attention, alertness, and impulse control.

Common side effects include nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence in pediatric patients, and constipation, dry mouth, nausea, and dizziness in adults [citation:1][citation:2].

• Treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) in patients 6 years and older [citation:1][citation:2]

Atomoxetine is a selective norepinephrine transporter inhibitor (NET inhibitor) [citation:2][citation:9]. It inhibits the pre-synaptic norepinephrine transporter, increasing norepinephrine levels in the synaptic cleft [citation:9]. It has weak affinity for the dopamine transporter and no significant affinity for other neurotransmitter receptors or transporters [citation:1].

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 [citation:1][citation:9].

Atomoxetine inhibits the pre-synaptic norepinephrine transporter, increasing norepinephrine levels in the synaptic cleft [citation:2][citation:9]. Norepinephrine helps regulate dopamine and norepinephrine activity in the prefrontal cortex, which improves attention, impulse control, and cognitive function. This leads to improvement in the core symptoms of ADHD [citation:11][citation:12].

Children & Adolescents (6 years+) - ADHD:

• Body weight ≤70 kg: Initial dose 0.5 mg/kg/day (once daily or divided into 2 doses). After minimum 3 days, increase to target dose 1.2 mg/kg/day. After 2-4 weeks, may increase to maximum 1.4 mg/kg/day or 100 mg/day (whichever is less) [citation:2].
• Body weight >70 kg: Initial dose 40 mg/day (once daily or divided into 2 doses). After minimum 3 days, increase to target dose 80 mg/day. After 2-4 weeks, may increase to maximum 100 mg/day [citation:2].

Adults - ADHD:

• Initial dose: 40 mg/day (once daily or divided into 2 doses). After minimum 3 days, increase to target dose 80 mg/day. After 2-4 weeks, may increase to maximum 100 mg/day [citation:2].

Hepatic Impairment:

• Moderate impairment (Child-Pugh Class B): Reduce dose by 50% [citation:1][citation:2].
• Severe impairment (Child-Pugh Class C): Reduce dose by 75% [citation:1][citation:2].

Renal Impairment: Dose adjustment may be needed in ESRD patients [citation:1][citation:2].

Take this medicine in the dose and duration as advised by your doctor. Swallow the capsule whole - do not open, chew, or crush. May be taken with or without food, but take at a fixed time [citation:1][citation:2].

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not double the dose.

Common Adverse Reactions in Children & Adolescents (≥5% and at least twice placebo):

• Nausea
• Vomiting
• Fatigue
• Decreased appetite
• Abdominal pain
• Somnolence

Common Adverse Reactions in Adults:

• Constipation
• Dry mouth
• Nausea
• Decreased appetite
• Dizziness
• Erectile dysfunction
• Urinary hesitation

Serious Adverse Reactions:

• Suicidal ideation in children and adolescents (0.4% of patients) [citation:1][citation:2]
• Severe liver damage (rare) [citation:10]
• Increased heart rate and blood pressure

Serious Precautions:

• Suicide risk: Atomoxetine increases the risk of suicidal ideation in children and adolescents [citation:1][citation:2]. Close monitoring is required during initiation and dose changes [citation:10].
• Liver damage: Inform your doctor immediately if you experience signs of liver problems (itching, right upper abdominal pain, dark urine, yellow skin/eyes) [citation:10].
• Cardiac risk: Caution in patients with heart problems, heart defects, or high blood pressure [citation:1][citation:2].
• Driving and machinery: Do not drive or operate hazardous machinery until you know how atomoxetine affects you [citation:10].
• Growth and weight monitoring: Monitor height and weight in children during treatment [citation:1].
• Do not stop suddenly: Do not stop taking the medication without talking to your doctor first.

• Hypersensitivity to atomoxetine or any component
• Concomitant use with or within 14 days of discontinuing MAO inhibitors [citation:1][citation:2]
• Angle-closure glaucoma

• MAO Inhibitors: Do not use atomoxetine within 14 days of starting or stopping an MAOI [citation:1][citation:2]
• CYP2D6 Inhibitors (e.g., paroxetine, fluoxetine, quinidine): May increase atomoxetine levels; dose adjustment may be needed [citation:1][citation:2]
• Antihypertensive and pressor agents: Possible effects on blood pressure [citation:1][citation:2]
• Albuterol (or other beta2 agonists): Cardiovascular effects may be potentiated [citation:1][citation:2]

[UNSAFE] It is unsafe to consume alcohol with Atomoxetine. Alcohol may increase the risk of drowsiness and dizziness.

[CONSULT YOUR DOCTOR] Insufficient safety data on atomoxetine use during pregnancy (Category B3) [citation:1][citation:2]. Animal studies have shown fetal risk. Use only if potential benefit justifies the risk [citation:1].

[CONSULT YOUR DOCTOR] It is unknown whether atomoxetine is excreted in human milk. Atomoxetine and its metabolites were excreted in the milk of rats. Caution is advised due to potential risk to the infant [citation:1][citation:2].

Pharmacokinetics in children under 6 years of age have not been evaluated [citation:1][citation:2]. Dosing table for 6-17 years is provided above.

Dose adjustment may be needed for elderly patients.

Hepatic Impairment: Moderate impairment (Child-Pugh Class B): reduce dose by 50%; severe impairment (Child-Pugh Class C): reduce dose by 75% [citation:1][citation:2].

Renal Impairment: Dose adjustment may be needed in ESRD patients [citation:1][citation:2].

There is no specific antidote for atomoxetine overdose. Symptomatic and supportive treatment is recommended. Overdose may cause nausea, vomiting, somnolence, dizziness, tremor, abnormal behavior, tachycardia, and increased blood pressure [citation:1][citation:2].

Store below 30°C, in a cool and dry place, protected from light. Keep out of reach of children.

Atomoxetine hydrochloride (C₁₇H₂₁NO · HCl)