Viloxazine Side Effects: What to Expect and When to Call Your Doctor

Understanding Viloxazine Side Effects

Viloxazine (brand name Qelbree) is a non-stimulant medication used to treat ADHD in patients aged 6 and older. Like all medications, it can cause side effects. Knowing what to expect can help you feel more confident about your treatment and know when something needs medical attention.

If you're new to this medication, start with our overview of what Viloxazine is and how it's used.

Common Side Effects of Viloxazine

Most side effects of Viloxazine are mild and may improve as your body adjusts to the medication. The most commonly reported side effects include:

• Drowsiness, fatigue, or sleepiness — This is one of the most common side effects. It may be more noticeable when you first start the medication.
• Decreased appetite — Some patients notice they feel less hungry, which can lead to weight loss over time.
• Nausea — Taking Viloxazine with food may help reduce nausea.
• Vomiting — Usually mild and tends to improve after the first few weeks.
• Headache — A common side effect that often gets better on its own.
• Insomnia — Some patients have trouble sleeping, especially when first starting treatment.
• Irritability — Mood changes can occur, particularly in children and adolescents.

Tips for Managing Common Side Effects

Here are a few practical tips that may help:

• Take it in the morning — Viloxazine is designed to be taken once daily in the morning, which can help reduce insomnia.
• Eat something first — Taking it with food may reduce nausea and vomiting.
• Give it time — Many side effects improve within the first 1–2 weeks of treatment.
• Stay hydrated — Drinking plenty of water can help with headaches and overall well-being.

Serious Side Effects to Watch For

While most side effects are mild, there are some serious side effects that require immediate medical attention:

Suicidal Thoughts and Behavior (Boxed Warning)

Viloxazine carries an FDA boxed warning about the risk of suicidal thoughts and behavior in children, adolescents, and young adults. This is the most serious warning the FDA can require.

Watch for these warning signs, especially during the first few months of treatment or when the dose is changed:

• New or worsening depression
• Talking about or thinking about self-harm or suicide
• Unusual changes in mood or behavior
• Withdrawal from friends and family
• Agitation or restlessness

If you notice any of these signs, contact your doctor right away or call 988 (Suicide and Crisis Lifeline).

Increased Blood Pressure and Heart Rate

Viloxazine can cause increases in blood pressure and heart rate. Your doctor should check your blood pressure and heart rate before starting treatment and periodically during treatment. Tell your doctor if you have a history of heart problems.

Activation of Mania or Hypomania

In patients with bipolar disorder, Viloxazine may trigger a manic or hypomanic episode. Symptoms include racing thoughts, decreased need for sleep, and unusual risk-taking behavior. Let your doctor know if you have a history of bipolar disorder.

Allergic Reactions

Though rare, allergic reactions can occur. Seek emergency medical help if you experience:

• Rash or hives
• Swelling of the face, lips, tongue, or throat
• Difficulty breathing

Side Effects in Children vs. Adults

Side effects can vary depending on age. In clinical trials:

• Children (ages 6–11) tended to experience more somnolence (sleepiness) and decreased appetite.
• Adolescents (ages 12–17) had similar side effects, with nausea being more common.
• Adults (18+) reported more insomnia, nausea, and fatigue.

Regardless of age, close monitoring is important — especially during the first few weeks and after dose changes.

How Viloxazine Side Effects Compare to Other ADHD Medications

Compared to stimulant ADHD medications, Viloxazine tends to have a different side effect profile. Stimulants commonly cause loss of appetite, difficulty sleeping, and increased heart rate. Viloxazine shares some of these (decreased appetite, insomnia) but is less likely to cause the jitteriness or anxiety sometimes associated with stimulants.

Compared to Atomoxetine (Strattera), another non-stimulant, Viloxazine has a unique mechanism of action that includes serotonin modulating activity, which may contribute to a different side effect experience.

If side effects become a problem, talk to your doctor about alternative ADHD medications.

Drug Interactions That Can Increase Side Effects

Certain medications can interact with Viloxazine and increase the risk or severity of side effects. For a full list, read our guide on Viloxazine drug interactions.

Key interactions to be aware of:

• MAO inhibitors — Never take Viloxazine with or within 14 days of an MAOI.
• CYP1A2 substrates — Viloxazine can increase levels of drugs like Duloxetine, Theophylline, and Tizanidine.
• Alcohol — May increase drowsiness and other CNS effects.

When to Call Your Doctor

Contact your doctor if you experience:

• Side effects that don't improve after 2 weeks
• Side effects that are severe or interfering with daily life
• Any signs of suicidal thoughts or behavior
• Rapid heartbeat, chest pain, or significant blood pressure changes
• Signs of an allergic reaction
• Symptoms of mania (racing thoughts, decreased need for sleep, risky behavior)

Don't stop taking Viloxazine without talking to your doctor first. They may want to adjust your dose or switch to a different medication.

Getting Your Prescription Filled

If you're currently taking Viloxazine and need to find it in stock, MedFinder can help you check pharmacy availability without calling around. You can also learn about savings programs and coupons to reduce your out-of-pocket costs.

Bottom Line

Most Viloxazine side effects are mild and manageable. Drowsiness, decreased appetite, nausea, and headache are the most common. However, the boxed warning about suicidal thoughts — especially in young patients — is important to take seriously. Stay in close contact with your doctor, especially during the first few months of treatment, and don't hesitate to reach out if something doesn't feel right.