Atomoxetine (Strattera) Drug Interactions: What to Avoid and What to Tell Your Doctor

Before starting atomoxetine (generic Strattera), it's essential to review your current medications with your prescriber and pharmacist. Several drug interactions range from serious (contraindicated) to significant (requiring dose adjustment) to worth monitoring. Here is a complete overview of what to know.

Contraindicated: Monoamine Oxidase Inhibitors (MAOIs)

The most dangerous interaction with atomoxetine is with MAOIs (monoamine oxidase inhibitors). Combining these drugs can cause a life-threatening hypertensive crisis — a sudden, dangerous spike in blood pressure.

MAOIs include:

Phenelzine (Nardil)

Tranylcypromine (Parnate)

Isocarboxazid (Marplan)

Selegiline (Emsam patch, Eldepryl)

Rasagiline (Azilect)

Linezolid (Zyvox) — an antibiotic with MAOI properties

Do not start atomoxetine within 2 weeks of stopping an MAOI. Do not start an MAOI within 2 weeks of stopping atomoxetine. This 2-week washout period is mandatory.

Major Interaction: CYP2D6 Inhibitors (Require Dose Adjustment)

Atomoxetine is metabolized by the liver enzyme CYP2D6. Drugs that inhibit this enzyme cause atomoxetine to build up in the bloodstream, potentially doubling or more than doubling atomoxetine plasma levels. This significantly increases side effect risk, including elevated heart rate, blood pressure, and psychiatric effects.

Common CYP2D6 inhibitors include:

Fluoxetine (Prozac): A strong CYP2D6 inhibitor; one of the most commonly co-prescribed medications with atomoxetine. Can increase atomoxetine levels by 100% or more.

Paroxetine (Paxil): Another potent CYP2D6 inhibitor with the same effect.

Quinidine: A cardiac medication and potent CYP2D6 inhibitor.

Bupropion (Wellbutrin): A moderate CYP2D6 inhibitor. Can increase atomoxetine levels if used concurrently.

Terbinafine (Lamisil): An antifungal that inhibits CYP2D6.

Dacomitinib: A cancer medication; avoid combination.

If you are taking a CYP2D6 inhibitor and starting atomoxetine, your prescriber should start at the low dose (40 mg/day) and increase only if response is inadequate and side effects are tolerable after 4 weeks. The maximum recommended dose when combined with strong CYP2D6 inhibitors is 80 mg/day.

Moderate Interaction: Cardiovascular Medications and Pressor Agents

Atomoxetine increases heart rate and blood pressure modestly (average increase of 5 beats/minute and 2 mmHg systolic in adults). When combined with medications that also affect blood pressure or heart rate, the effects may be additive.

Albuterol and other beta-agonists: Inhaled albuterol (for asthma/COPD) may have enhanced cardiovascular effects when combined with atomoxetine. Use with caution.

Antihypertensives: Atomoxetine may blunt the effectiveness of blood pressure-lowering medications or add to blood pressure effects.

Moderate Interaction: QT-Prolonging Drugs

Atomoxetine has mild QT-prolonging effects on cardiac rhythm. Combining it with other medications that also prolong the QT interval can increase the risk of serious heart rhythm abnormalities. Drugs in this category include:

Antipsychotics (e.g., amisulpride, haloperidol, quetiapine)

Certain antibiotics (e.g., azithromycin, erythromycin)

Buprenorphine products (Suboxone, Sublocade)

Methadone

If you are on any of these medications, your prescriber should perform baseline and follow-up ECG monitoring when starting atomoxetine.

What to Tell Your Doctor and Pharmacist

Before starting atomoxetine, provide a complete medication list — including prescriptions, over-the-counter medications, vitamins, and supplements. Key things to flag:

Any MAOI (even if recently stopped — require 2-week washout)

Fluoxetine or paroxetine (common antidepressants that are also CYP2D6 inhibitors)

Any heart medications (especially antiarrhythmics like amiodarone or quinidine)

Albuterol inhalers (asthma or COPD medications)

Buprenorphine products (Suboxone, Sublocade)

The Bottom Line

Most people can safely take atomoxetine with their other medications — but the CYP2D6 interaction with common antidepressants like fluoxetine and paroxetine is frequently missed. Always tell your prescriber and pharmacist about every medication you're taking. See also our guide on atomoxetine side effects for a full picture of what to watch for.