Please check your internet connection and try again.
# Atomoxetine
## Overview
Atomoxetine is a selective norepinephrine reuptake inhibitor (SNRI) used primarily for the management of Attention-Deficit/Hyperactivity Disorder (ADHD). Unlike stimulants, it is non-habit forming and does not have abuse potential.
## Primary Indications
* Attention-Deficit/Hyperactivity Disorder (ADHD) in children, adolescents, and adults.
## Adult Dosing
* **Initial Dose:** 40 mg orally once daily.
* **Titration:** Maintain for at least 3 days. May increase to 80 mg total daily dose, administered either as a single dose in the morning or divided into two doses (morning and late afternoon).
* **Max Dose:** 100 mg daily if no improvement after 2–4 weeks at 80 mg.
## Pediatric Dosing
* **Weight < 70 kg:** 0.5 mg/kg once daily for at least 3 days. Titrate to a target dose of ~1.2 mg/kg per day (given as once daily or divided BID).
* **Weight ≥ 70 kg:** Follow adult dosing guidelines.
* **Max Dose:** 1.4 mg/kg or 100 mg daily, whichever is lower.
## Dose Adjustments
* **Hepatic Impairment:** Reduce initial and target dose by 50% in patients with moderate hepatic impairment (Child-Pugh Class B). Reduce by 75% in severe impairment (Child-Pugh Class C).
* **CYP2D6 Poor Metabolizers:** Consider lower starting dose; monitor closely.
## Contraindications
* Hypersensitivity to atomoxetine.
* Concomitant use (or within 14 days of discontinuing) MAOIs.
* Narrow-angle glaucoma.
* Severe cardiovascular disorders (e.g., severe hypertension, heart failure, arrhythmias) where increases in BP/HR would be clinically detrimental.
* Current or past history of pheochromocytoma.
## Adverse Effects
* **Common:** Dry mouth, nausea, abdominal pain, decreased appetite, insomnia, fatigue, and dizziness.
* **Serious:** Severe liver injury (rare), suicidal ideation in children/adolescents, orthostatic hypotension, tachycardia, and potential for priapism.
## Key Drug Interactions
* **MAOIs:** Risk of hypertensive crisis.
* **CYP2D6 Inhibitors (e.g., fluoxetine, paroxetine, quinidine):** May significantly increase atomoxetine blood levels; reduce atomoxetine dose if co-administered.
* **Antihypertensives:** Potential to antagonize blood pressure-lowering effects.
* **Albuterol:** Risk of increased cardiovascular effects (tachycardia/BP elevation).
## Monitoring
* **Baseline:** Cardiac assessment (BP, Heart Rate, history of cardiovascular disease).
* **Ongoing:** Monitor BP and HR at every dose adjustment.
* **Psychiatric:** Monitor for emergence or worsening of suicidal ideation, anxiety, or agitation.
* **Liver:** Monitor for signs of hepatic injury (jaundice, pruritus, dark urine) although routine LFT monitoring is not required unless symptoms manifest.
## Clinical Pearls
* **Onset of Action:** Unlike stimulants, therapeutic effect can take 2–4 weeks; full benefit may require 6–8 weeks.
* **GI Distress:** Taking with food or splitting the dose (if BID) can mitigate nausea.
* **Non-Stimulant:** Preferred in patients with a history of substance use disorder or those who cannot tolerate stimulant-related anxiety/insomnia.
***
**EDUCATIONAL DISCLAIMER:** This information is for educational purposes only and does not constitute medical advice. Prescribing practices vary by institution and regional guidelines. Always verify current prescribing information, dosing, and contraindications using official manufacturer labels and clinical decision support tools (e.g., Lexicomp, UpToDate) before initiating therapy.
