Qelbree Drug Interactions You Need to Know About

If you're taking Qelbree (Viloxazine) for ADHD, it's important to understand which medications, supplements, and even foods could interact with it. Some interactions are inconvenient; others can be dangerous.

This guide covers the major and moderate drug interactions based on FDA labeling, so you know what to avoid and what to discuss with your doctor.

How Drug Interactions Work with Qelbree

Qelbree is processed by your liver, and it has a significant effect on how your body handles other drugs. Specifically, Qelbree is a strong inhibitor of CYP1A2 and a weak inhibitor of CYP2D6 — two liver enzymes responsible for breaking down many common medications.

When Qelbree blocks these enzymes, it can cause other drugs to build up to higher-than-normal levels in your blood. This can increase both the effects and side effects of those medications, sometimes to dangerous levels.

Medications That Interact with Qelbree

Contraindicated (Do Not Combine)

These combinations are considered dangerous and should be avoided entirely:

MAO Inhibitors (MAOIs)

• Phenelzine (Nardil)
• Tranylcypromine (Parnate)
• Isocarboxazid (Marplan)
• Selegiline (Emsam, Eldepryl)

Do not take Qelbree within 14 days of stopping an MAOI, and do not start an MAOI within 14 days of stopping Qelbree. Combining them can cause a hypertensive crisis — a sudden, dangerous spike in blood pressure.

CYP1A2 Substrates with Narrow Therapeutic Range

These medications rely on precise blood levels to be safe. Because Qelbree can dramatically increase their levels, combining them is contraindicated or should be avoided:

• Theophylline — used for asthma and COPD
• Tizanidine (Zanaflex) — a muscle relaxant
• Alosetron (Lotronex) — used for irritable bowel syndrome
• Duloxetine (Cymbalta) — an antidepressant and pain medication
• Fluvoxamine (Luvox) — an antidepressant/OCD medication

Major Interactions (Use with Caution)

Other CYP1A2 Substrates

These medications may have their blood levels increased by Qelbree. Your doctor may need to adjust doses or monitor you more closely:

• Ramelteon (Rozerem) — a sleep medication
• Tasimelteon (Hetlioz) — used for sleep-wake disorder
• Melatonin — the popular sleep supplement (yes, even melatonin)
• Caffeine — more on this below

CYP2D6 Substrates

Qelbree weakly inhibits CYP2D6, which can affect these medications:

• Atomoxetine (Strattera) — another ADHD medication
• Dextromethorphan — found in many cough medicines (Robitussin DM, Delsym, NyQuil)

Moderate Interactions

Other Serotonergic Medications

Because Qelbree modulates serotonin transmission, combining it with other serotonergic drugs increases the risk of serotonin syndrome — a potentially life-threatening condition. Be cautious with:

• SSRIs like Sertraline (Zoloft), Fluoxetine (Prozac), Escitalopram (Lexapro)
• SNRIs like Venlafaxine (Effexor), Desvenlafaxine (Pristiq)
• Triptans for migraines like Sumatriptan (Imitrex)
• Tramadol (Ultram) — a pain medication
• St. John's Wort — an herbal supplement

Symptoms of serotonin syndrome include agitation, confusion, rapid heart rate, high blood pressure, dilated pupils, muscle twitching, and high body temperature. Seek emergency care immediately if you experience these symptoms.

Supplements and OTC Medications to Watch

Don't forget about things you can buy without a prescription:

• Melatonin: Qelbree can increase melatonin levels because melatonin is a CYP1A2 substrate. You may need a lower dose or should talk to your doctor before combining them.
• Dextromethorphan (DXM): Found in many over-the-counter cough medicines. Qelbree can increase DXM levels. Check ingredient labels on cold and flu medications.
• St. John's Wort: This herbal supplement affects serotonin and could increase the risk of serotonin syndrome when combined with Qelbree.
• 5-HTP and L-Tryptophan: Serotonin precursor supplements that could theoretically increase serotonin syndrome risk.

Food and Drink Interactions

Caffeine

This is the one that surprises most people. Caffeine is metabolized by CYP1A2, and since Qelbree is a strong CYP1A2 inhibitor, Qelbree can significantly increase caffeine levels in your body.

What this means in practice:

• Your morning coffee may feel stronger than usual
• You may experience jitteriness, anxiety, or insomnia from your normal caffeine intake
• Consider reducing your caffeine consumption when starting Qelbree and adjusting based on how you feel

Food

There are no significant food interactions that affect Qelbree's absorption. You can take it with or without food.

What to Tell Your Doctor

Before starting Qelbree, give your doctor a complete list of everything you take, including:

• All prescription medications
• Over-the-counter drugs (especially cold/cough medicines)
• Vitamins and supplements (including melatonin, St. John's Wort, 5-HTP)
• How much caffeine you consume daily

Also tell your doctor if:

• You've taken an MAOI in the past 14 days
• You have a history of serotonin syndrome
• You have liver or kidney problems (Qelbree dosing may need adjustment)
• You're pregnant, planning to become pregnant, or breastfeeding

Keep this list updated and bring it to every appointment. Pharmacists are also an excellent resource — they can check for interactions when you fill your prescription.

Final Thoughts

Drug interactions with Qelbree are manageable, but they're important to take seriously — especially the contraindicated combinations with MAOIs and narrow-therapeutic-range CYP1A2 substrates. The caffeine interaction catches many people off guard, so pay attention to how your coffee affects you after starting treatment.

For more about how Qelbree works in your body, read our mechanism of action explainer. And if you need help locating Qelbree at a pharmacy near you, Medfinder can help.