atomoxetine

(a-to-mox-e-teen) atomoxetine,

Strattera

(trade name)

Classification

Therapeutic: agents for attention deficit disorder
Pharmacologic: selective norepinephrine reuptake inhibitors
Pregnancy Category: C

Indications

Attention-Deficit/Hyperactivity Disorder (ADHD).

Action

Selectively inhibits the presynaptic transporter of norepinephrine.

Therapeutic effects

Increased attention span.

Pharmacokinetics

Absorption: Well absorbed following oral administration.Distribution: Unknown.Protein Binding: 98%.Metabolism and Excretion: Mostly metabolized by the liver (CYP2D6 enzyme pathway). genetic implication A small percentage of the population are poor metabolizers and will have higher blood levels with ↑ effects.Half-life: 5 hr.

Time/action profile

ROUTE	ONSET	PEAK	DURATION
PO	unknown	1–2 hr	12–24 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity;Concurrent or within 2 wk therapy with MAO inhibitors;Angle-closure glaucoma;Pheochromocytoma;Hypertension, tachycardia, cardiovascular or cerebrovascular disease.Use Cautiously in: Pre-existing psychiatric illness; Pediatric: May ↑ risk of suicide attempt/ideation especially during dose early treatment or dose adjustment; risk may be greater in children or adolescents;Concurrent albuterol or vasopressors (↑ risk of adverse cardiovascular reactions); Obstetric: Use only if benefits outweigh risks to fetus; Lactation / Pediatric: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

suicidal thoughts (life-threatening)
dizziness (most frequent)
fatigue (most frequent)
mood swings (most frequent)
behavioral disturbances
hallucinations
hostility
mania
thought disorder

Adults:

insomnia (most frequent)

Cardiovascular

hypertension
orthostatic hypotension
QT interval prolongation
syncope
tachycardia

Gastrointestinal

hepatotoxicity (life-threatening)
dyspepsia
nausea (most frequent)
vomiting (most frequent)

Adults:

dry mouth
constipation (most frequent)

Dermatologic

rash
urticaria

Genitourinary

Adults:

dysmenorrhea (most frequent)
ejaculatory problems (most frequent)
↓ libido (most frequent)
erectile dysfunction (most frequent)
urinary hesitation
urinary retention

Metabolic

↓ appetite (most frequent)
weight/growth loss

Neurologic

Adults:

paresthesia

Miscellaneous

allergic reactions including angioneurotic edema and anaphylaxis (life-threatening)

Interactions

Drug-Drug interaction

Concurrent use with MAO inhibitors may result in serious, potentially fatal reactions (do not use within 2 wk of each other).↑ risk of cardiovascular effects with albuterol or vasopressors (use cautiously).Drugs which inhibit the CYP2D6 enzyme pathway (quinidine, fluoxetine, paroxetine ) will increase blood levels and effects, dose ↓ recommended.

Route/Dosage

Oral (Children and adolescents <70 kg) 0.5 mg/kg/day initially, may be ↑ every 3 days to a daily target dose of 1.2 mg/kg, given as a single dose in the morning or evenly divided doses in the morning and late afternoon/early evening (not to exceed 1.4 mg/kg/day or 100 mg/day whichever is less). If taking concurrent CYP2D6 inhibitor (quinidine, fluoxetine, paroxetine)—0.5 mg/kg/day initially, may ↑ if needed to 1.2 mg/kg/day after 4 wk.Oral (Adults, adolescents, and children >70 kg) 40 mg/day initially, may be ↑ every 3 days to a daily target dose of 80 mg/day given as a single dose in the morning or evenly divided doses in the morning and late afternoon/early evening; may be further ↑ after 2–4 wk up to 100 mg/day. If taking concurrent CYP2D6 inhibitor (quinidine, fluoxetine, paroxetine)—40 mg/day initially, may ↑ if needed to 80 mg/day after 4 wk.

Hepatic Impairment

Oral (Adults and Children) Moderate hepatic impairment (Child-Pugh Class B)—↓ initial and target dose by 50%; Severe hepatic impairment (Child-Pugh Class C)—↓ initial and target dose to 25% of normal.

Availability (generic available)

Capsules: 10 mg, 18 mg, 25 mg, 40 mg, 60 mg, 80 mg, 100 mg

Nursing implications

Nursing assessment

Assess attention span, impulse control, and interactions with others.
Monitor BP and pulse periodically during therapy. Obtain a history (including assessment of family history of sudden death or ventricular arrhythmia), physical exam to assess for cardiac disease, and further evaluation (ECG and echocardiogram), if indicated. If exertional chest pain, unexplained syncope, or other cardiac symptoms occur, evaluate promptly.
Monitor growth, body height, and weight in children.
Assess for signs of liver injury (pruritus, dark urine, jaundice, right upper quadrant tenderness, unexplained "flu-like" symptoms) during therapy. Monitor liver function tests at first sign of liver injury. Discontinue and do not restart atomoxetine in patients with jaundice or laboratory evidence of liver injury.
Monitor closely for notable changes in behavior that could indicate the emergence or worsening of suicidal thoughts or behavior or depression.

Potential Nursing Diagnoses

Disturbed thought process (Indications)
Impaired social interaction (Indications)

Implementation

Oral: Administer without regard to food. Capsules should be swallowed whole; do not open, crush, or chew. Doses may be discontinued without tapering.

Patient/Family Teaching

Instruct patient to take medication as directed. Take missed doses as soon as possible, but should not take more than the total daily amount in any 24-hr period. Advise patient and parents to read the Medication Guide prior to starting therapy and with each Rx refill.
Inform patient that sharing this medication may be dangerous.
Advise patient to notify health care professional immediately if signs of liver injury occur.
Advise patient and family to notify health care professional if thoughts about suicide or dying, attempts to commit suicide; new or worse depression; new or worse anxiety; feeling very agitated or restless; panic attacks; trouble sleeping; new or worse irritability; acting aggressive or hostile; being angry or violent; acting on dangerous impulses; an extreme increase in activity and talking; other unusual changes in behavior or mood occur or if signs and symptoms of severe liver injury (pruritus, dark urine, jaundice, right upper quadrant tenderness, or unexplained "flu-like" symptoms) occur.
Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications.
May cause dizziness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
Advise female patients to notify health care professional if pregnancy is planned or suspected or if they are breast feeding.
Pediatric: Advise parents to notify school nurse of medication regimen.

Evaluation/Desired Outcomes

Improved attention span and social interactions in ADHD.

atomoxetine

A highly selective inhibitor of the pre-synaptic noradrenaline transporter used to reduce the signs and symptoms of ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD) in children over six years of age. A brand name is STRATTERA.