Mydayis XR Drug Interactions: What to Avoid and What to Tell Your Doctor

Mydayis XR can interact with a number of other medications, supplements, and even common foods and beverages. Some of these interactions are serious — potentially life-threatening. Others simply change how well the medication works. Knowing what to avoid and what to tell your doctor is one of the most important things you can do for your safety.

This guide covers the most clinically significant interactions, organized from most serious to least serious.

CRITICAL: MAOIs (Monoamine Oxidase Inhibitors)

The most dangerous interaction with Mydayis XR is with MAOIs (monoamine oxidase inhibitors). This combination is absolutely contraindicated — meaning it must never happen.

MAOIs include antidepressants like phenelzine (Nardil), tranylcypromine (Parnate), isocarboxazid (Marplan), and selegiline (Emsam). They are also used in other contexts — linezolid (an antibiotic) and methylene blue (used in some medical procedures) also inhibit MAO.

Taking Mydayis with an MAOI — or within 14 days of stopping an MAOI — can trigger a hypertensive crisis (a sudden, dangerous spike in blood pressure) or life-threatening serotonin syndrome. Even a single dose overlap can be fatal.

Rule: Do not take Mydayis XR if you have taken an MAOI in the last 14 days. Wait at least 14 days after stopping an MAOI before starting Mydayis. Always tell your prescriber if you've ever taken an MAOI.

Serotonin Syndrome Risk: Antidepressants and Other Serotonergic Drugs

Because Mydayis XR raises serotonin levels, combining it with other serotonin-increasing medications raises the risk of serotonin syndrome — a potentially life-threatening condition characterized by agitation, high fever, muscle rigidity, rapid heart rate, and seizures.

Medications that can increase this risk when combined with Mydayis:

• SSRIs (selective serotonin reuptake inhibitors): citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft)
• SNRIs (serotonin-norepinephrine reuptake inhibitors): venlafaxine (Effexor), duloxetine (Cymbalta), desvenlafaxine (Pristiq)
• Tricyclic antidepressants: amitriptyline, imipramine, nortriptyline
• Triptans (migraine medications): sumatriptan (Imitrex), rizatriptan (Maxalt), zolmitriptan
• Other: lithium, tramadol, fentanyl, buspirone, St. John's Wort, tryptophan supplements

This doesn't mean these combinations are always prohibited — many ADHD patients also have depression or anxiety and take an SSRI alongside their stimulant medication. But these combinations require careful monitoring. Your prescriber should know about all serotonergic drugs you take so they can start Mydayis at a lower dose and watch for early signs of serotonin syndrome.

Acid-Reducing Medications: May Increase Mydayis Effects

Proton pump inhibitors (PPIs) and other acid-reducing medications increase stomach pH, which speeds up the absorption of amphetamine from Mydayis's beads. This can cause you to absorb more of the drug more quickly, intensifying both the desired effects and side effects.

Common acid reducers that interact with Mydayis:

• PPIs: omeprazole (Prilosec), esomeprazole (Nexium), pantoprazole (Protonix), lansoprazole (Prevacid)
• H2 blockers: famotidine (Pepcid), ranitidine (Zantac — where still available)
• Antacids: sodium bicarbonate (baking soda), calcium carbonate (Tums)

If you regularly take any of these, tell your prescriber. A lower dose of Mydayis may be appropriate, or your doctor may adjust timing.

Acidic Substances: May Decrease Mydayis Effects

On the opposite end, substances that acidify your gut or urine can reduce amphetamine absorption and make Mydayis less effective:

• Vitamin C (ascorbic acid) — A common supplement. Avoid taking vitamin C supplements or drinking large amounts of citrus juice close to when you take Mydayis.
• Ammonium chloride — Found in some expectorants
• Fruit juices — Particularly orange and grapefruit juice taken around the same time as your dose

Blood Pressure Medications

Mydayis XR raises blood pressure and heart rate. If you're already taking antihypertensive medications (for high blood pressure), Mydayis may reduce their effectiveness. Your doctor will need to monitor your blood pressure more closely and may need to adjust your blood pressure medication.

Alcohol: A Dangerous Combination

Lab testing has shown that alcohol increases the release rate of amphetamine from Mydayis capsules. This means drinking alcohol while taking Mydayis can cause a dangerous spike in amphetamine levels, significantly increasing the risk of overdose-like symptoms. The FDA advises against drinking alcohol while on Mydayis.

CYP2D6 Inhibitors

Mydayis is partially metabolized by the CYP2D6 enzyme. Medications that inhibit this enzyme can increase Mydayis levels in the blood, raising the risk of side effects including serotonin syndrome. CYP2D6 inhibitors include certain antidepressants (fluoxetine, paroxetine, bupropion) and antipsychotics (haloperidol, thioridazine).

What to Tell Your Doctor Before Starting Mydayis XR

Before your prescriber starts you on Mydayis XR, provide a complete list of every medication you take — including:

• All prescription medications, including those for depression, anxiety, blood pressure, seizures, and pain
• Over-the-counter medications (acid reducers, cold medicines, decongestants)
• All vitamins and supplements, including vitamin C and tryptophan
• Herbal products, especially St. John's Wort

For a deeper look at what to watch for once you start treatment, read our guide on Mydayis XR side effects and when to call your doctor. And if you need help finding Mydayis in stock, Medfinder can locate it at a pharmacy near you.