Nurses Compass
Drug Guide
Atomoxetine Hydrochloride
Classification
Therapeutic: Central nervous system stimulant, used for ADHD
Pharmacological: Selective norepinephrine reuptake inhibitor
FDA Approved Indications
- Attention deficit hyperactivity disorder (ADHD) in children, adolescents, and adults
Mechanism of Action
Atomoxetine selectively inhibits the norepinephrine reuptake transporter, increasing norepinephrine levels in the synaptic cleft, which helps improve attention and reduce impulsivity and hyperactivity.
Dosage and Administration
Adult: Starting dose of 40 mg once daily or divided into two doses; dose may be increased after at least 3 days to a maximum of 100 mg/day based on response and tolerability.
Pediatric: Recommended starting dose is 0.5 mg/kg once daily; may be increased to a maximum of 1.4 mg/kg/day or 100 mg/day after at least 3 days.
Geriatric: Use with caution, starting with lower doses and monitoring closely.
Renal Impairment: Use with caution; may require dose adjustments, particularly in severe impairment.
Hepatic Impairment: Start with 0.5 mg/kg once daily; maximum dose of 100 mg/day due to hepatic metabolism.
Pharmacokinetics
Absorption: Well absorbed orally, with peak plasma concentrations in 1-2 hours.
Distribution: Approximately 99% bound to plasma proteins.
Metabolism: Extensively metabolized by liver enzymes, predominantly CYP2D6, to inactive metabolites.
Excretion: Primarily excreted in urine as inactive metabolites; a small amount is eliminated via feces.
Half Life: Approximately 5.2 hours with CYP2D6 extensive metabolizers; longer (up to 21 hours) in poor metabolizers.
Contraindications
- Hypersensitivity to atomoxetine or any component of the formulation
- Use of monoamine oxidase inhibitors (MAOIs) within the past 14 days
Precautions
- History of glaucoma, cardiovascular or cerebrovascular disease, urinary retention, severe hot flushes, or pheochromocytoma.
- Increased risk of suicidal thoughts, especially in children and adolescents. Close monitoring recommended.
Adverse Reactions - Common
- Dry mouth (Common)
- Appetite suppression (Common)
- Nausea (Common)
- Insomnia (Common)
- Dizziness (Common)
Adverse Reactions - Serious
- Liver injury (hepatotoxicity) (Rare)
- Cardiovascular events such as increased blood pressure or heart rate (Uncommon)
- Suicidal ideation or behavior (Uncommon)
Drug-Drug Interactions
- CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, quinidine) increase plasma levels of atomoxetine.
- Blood pressure medications may have additive effects.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor blood pressure, heart rate, and mental health status regularly.
Diagnoses:
- Risk of decreased cardiac output
- Risk of suicidal ideation
Implementation: Administer as prescribed, monitor for adverse effects, educate patient about signs of liver injury and suicidal thoughts.
Evaluation: Assess behavioral improvements and side effects periodically.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report symptoms of liver problems (jaundice, dark urine).
- Avoid abrupt discontinuation.
- Seek medical attention if symptoms of cardiovascular issues or mood changes occur.
Special Considerations
Black Box Warnings:
- Risk of suicidality in children and adolescents.
- Hepatotoxicity—severity and need for monitoring.
- Potential for aggressive behavior or hostility.
Genetic Factors: CYP2D6 metabolizer status affects drug levels; poor metabolizers have higher plasma concentrations.
Lab Test Interference: May interfere with certain liver function tests.
Overdose Management
Signs/Symptoms: Altered mental status, agitation, tachycardia, hypertension, vomiting, drowsiness.
Treatment: Supportive care, activated charcoal if ingestion is recent, and monitoring of cardiac status.
Storage and Handling
Storage: Store at room temperature, 20-25°C (68-77°F).
Stability: Stable under recommended storage conditions for at least 24 months.