Atomoxetine Overdose: What to Watch For and How It’s Treated

Atomoxetine, sold under the brand name Strattera, is a non-stimulant medication used to treat ADHD in children, teens, and adults. Unlike stimulants like Adderall or Ritalin, it works by increasing norepinephrine in the brain to improve focus and reduce impulsivity. It’s often chosen when stimulants cause anxiety, sleep issues, or aren’t tolerated. But like any medication, taking too much can be dangerous. An atomoxetine overdose doesn’t always look like a dramatic emergency-but it can be life-threatening if ignored.

What Happens When You Take Too Much Atomoxetine?

There’s no single number that defines an overdose. For adults, doses over 100 mg in a single day can cause serious symptoms. In children, even 50 mg or more may lead to toxicity, depending on weight and tolerance. Most overdose cases happen accidentally-like taking a double dose because a pill was missed-or intentionally, often in suicide attempts.

Atomoxetine is metabolized by the liver, mainly through the CYP2D6 enzyme. People who are slow metabolizers (about 7% of Caucasians) build up the drug faster, making them more vulnerable to overdose even at normal doses. This is why doctors start with lower doses for these individuals.

The effects of an overdose don’t always show up right away. Symptoms can begin within 1 to 4 hours, but sometimes take up to 12 hours to fully develop. That delay is why waiting to see if you "feel okay" after taking too much is a dangerous mistake.

Signs of an Atomoxetine Overdose

Overdose symptoms range from mild to severe. They’re not always obvious, and many people mistake them for a bad reaction or just feeling "off." Here’s what to look for:

• Fast or irregular heartbeat (tachycardia or arrhythmias)-this is one of the most common and dangerous signs
• High blood pressure-systolic readings over 180 mmHg can strain the heart and blood vessels
• Extreme drowsiness or agitation-some people become lethargic, others become restless or aggressive
• Nausea, vomiting, or stomach pain-often mistaken for the flu
• Blurred vision or dilated pupils
• Shaking or tremors-especially in the hands
• Confusion, hallucinations, or delusions-rare but serious
• Seizures-a medical emergency that requires immediate intervention
• Loss of consciousness-this is a critical red flag

One of the biggest risks is cardiac toxicity. Atomoxetine can prolong the QT interval on an ECG, which can lead to a dangerous heart rhythm called torsades de pointes. This can cause sudden cardiac arrest-even in people with no prior heart problems.

What to Do If You Suspect an Overdose

If you or someone else has taken too much atomoxetine, don’t wait for symptoms to get worse. Call emergency services immediately. In New Zealand, dial 111. In the U.S., call 911. In the UK, call 999. Don’t try to drive yourself to the hospital unless you’re fully alert and stable.

While waiting for help:

• Keep the person awake and sitting up if possible
• Do NOT induce vomiting unless told to by a poison control center
• Have the medication bottle ready to show medical staff-this helps them know the exact dose and formulation
• If the person is unconscious but breathing, place them in the recovery position
• If they stop breathing, begin CPR if you’re trained

Emergency responders will likely give oxygen, start IV fluids, and monitor heart rhythm continuously. In the hospital, they’ll check blood levels, do an ECG, and run blood tests to assess liver and kidney function.

How Doctors Treat Atomoxetine Overdose

There’s no specific antidote for atomoxetine. Treatment is all about managing symptoms and supporting the body until the drug is cleared.

Common hospital treatments include:

• Activated charcoal-given within 1-2 hours of ingestion to reduce absorption, but only if the person is alert and able to swallow
• IV fluids-to maintain blood pressure and help flush the drug through the kidneys
• Heart monitoring-continuous ECG for at least 12-24 hours to catch arrhythmias early
• Beta-blockers-like metoprolol or esmolol, used to control rapid heart rate and high blood pressure
• Antiseizure medication-if seizures occur, lorazepam or levetiracetam may be used
• Sedation-for severe agitation or hallucinations, benzodiazepines like diazepam are often effective
• Intubation and ventilation-only if breathing fails or the person becomes unresponsive

Most patients recover fully if treated within 6-8 hours. But delays can lead to complications like stroke, heart attack, or permanent brain damage from lack of oxygen during a seizure or cardiac event.

Who’s at Highest Risk?

Not everyone who takes too much atomoxetine will have a severe reaction. But certain factors raise the risk:

• Children and teens-their bodies process the drug differently and are more sensitive to its effects
• People with heart conditions-especially those with arrhythmias, long QT syndrome, or untreated high blood pressure
• Slow CYP2D6 metabolizers-genetic variation means the drug stays in their system longer
• People mixing atomoxetine with other drugs-like antidepressants (SSRIs, SNRIs), MAOIs, or alcohol-can increase toxicity
• Those with liver disease-reduces the body’s ability to break down the drug

Even if you’ve been taking atomoxetine for months without issues, an overdose can still happen suddenly. One extra pill, one missed meal, or one bad night’s sleep can change how your body handles the drug.

Preventing an Overdose

The best treatment is prevention. Here’s how to stay safe:

• Always take atomoxetine exactly as prescribed-never adjust the dose without talking to your doctor
• Use a pill organizer if you’re on multiple medications
• Keep your medication locked up if children or teens are in the home
• Never share your prescription-what’s safe for you could be dangerous for someone else
• Set phone reminders for doses to avoid double-taking
• Store the bottle in its original packaging with the label intact-this helps medical staff identify the drug quickly in an emergency
• Know your doctor’s after-hours contact info or the poison control number in your country

Many people feel embarrassed about taking too much medication. But delaying help because of shame can be deadly. Emergency teams are trained to handle these situations without judgment. Your safety matters more than guilt.

What Happens After an Overdose?

If you survive an overdose, you’ll likely be monitored for 24-48 hours. Once stable, you’ll be referred for follow-up care. This isn’t just about physical recovery-it’s about understanding why it happened.

If the overdose was accidental, your doctor may adjust your dose, switch medications, or add support tools like pill dispensers. If it was intentional, mental health support is essential. ADHD is often linked with depression, anxiety, or impulsivity disorders. Treating the root cause is just as important as treating the overdose.

Follow-up appointments are non-negotiable. Even if you feel fine, your heart and liver need time to recover. Blood tests and ECGs may be repeated a week later to make sure everything has returned to normal.

When to Call Poison Control

You don’t need to wait for symptoms to appear. If you’re unsure whether you’ve taken too much, call your local poison control center. In New Zealand, it’s 0800 764 766 (Poison Centre). In the U.S., it’s 1-800-222-1222. They’re available 24/7 and can give you real-time advice based on your weight, age, and how much you took.

They’ll ask:

• How much atomoxetine was taken?
• When was it taken?
• Are there any symptoms?
• Are other drugs or alcohol involved?

Don’t hesitate to call-even if you think it’s "not that bad." It’s better to be safe.