Why Drug Interactions Matter When You're Taking Relexxii

If you take Relexxii (methylphenidate hydrochloride extended-release) for ADHD, it's important to know that certain medications, supplements, and even some foods can interact with it — sometimes dangerously. Drug interactions can make Relexxii less effective, increase side effects, or create new health risks.

This guide covers the interactions you need to know about and what to tell your doctor before starting Relexxii.

How Drug Interactions Work

A drug interaction happens when one substance changes how another works in your body. This can happen in several ways:

• One drug increases the effect of another — leading to stronger effects or toxicity
• One drug decreases the effect of another — making it less effective
• Two drugs combine to create a new risk — such as serotonin syndrome or hypertensive crisis

Relexxii works by increasing dopamine and norepinephrine levels in the brain (learn more about how Relexxii works). Any medication that also affects these neurotransmitters — or that is affected by their increased levels — has the potential to interact.

Dangerous Interactions: Medications to Avoid

MAO Inhibitors (MAOIs) — Do Not Combine

This is the most critical interaction. Do not take Relexxii if you are currently taking an MAO inhibitor or have taken one within the past 14 days. MAOIs include:

• Phenelzine (Nardil)
• Tranylcypromine (Parnate)
• Isocarboxazid (Marplan)
• Selegiline (Emsam) at higher doses
• Linezolid (Zyvox) — an antibiotic that also has MAOI activity
• Methylene blue (intravenous)

Combining Relexxii with an MAOI can cause a hypertensive crisis — a sudden, dangerous spike in blood pressure that can lead to stroke or death. There must be at least a 14-day washout period between stopping an MAOI and starting Relexxii.

Halogenated Anesthetics

If you're having surgery that uses halogenated anesthetic agents (like sevoflurane, desflurane, or isoflurane), there's a risk of sudden blood pressure and heart rate increases. Tell your surgeon and anesthesiologist that you take Relexxii. Your doctor may advise stopping the medication before a planned surgery.

Serotonergic Medications

Taking Relexxii with drugs that increase serotonin levels raises the risk of serotonin syndrome — a potentially life-threatening condition. Serotonergic medications include:

• SSRIs — fluoxetine (Prozac), sertraline (Zoloft), escitalopram (Lexapro), paroxetine (Paxil)
• SNRIs — venlafaxine (Effexor), duloxetine (Cymbalta)
• Triptans — sumatriptan (Imitrex) and other migraine medications
• Certain pain medications — tramadol, fentanyl, meperidine

This doesn't mean you can never take an SSRI with Relexxii — many patients safely use both under medical supervision. But your doctor needs to know about the combination and monitor you for symptoms like agitation, rapid heartbeat, high body temperature, and muscle rigidity.

Moderate Interactions: Use With Caution

Blood Thinners (Coumarin Anticoagulants)

Methylphenidate may increase the blood levels of coumarin anticoagulants like warfarin (Coumadin). If you take a blood thinner, your doctor may need to monitor your INR more closely when starting or adjusting Relexxii.

Anticonvulsants

Relexxii may increase blood levels of certain seizure medications, including:

• Phenobarbital
• Phenytoin (Dilantin)
• Primidone (Mysoline)

Your doctor may need to adjust the doses of these medications if you start Relexxii.

Tricyclic Antidepressants

Methylphenidate can increase levels of tricyclic antidepressants (TCAs) like amitriptyline, nortriptyline, and imipramine. This can increase the risk of TCA side effects. Dose adjustments may be needed.

Blood Pressure Medications

Because Relexxii can raise blood pressure, it may reduce the effectiveness of antihypertensive drugs. If you take medication for high blood pressure, your doctor should monitor your readings more frequently after starting Relexxii.

Pressor Agents

Medications that raise blood pressure (pressor agents like epinephrine or norepinephrine, sometimes used in medical settings) should be used with caution alongside Relexxii.

Supplements and Over-the-Counter Medications

Don't assume that "natural" or OTC products are safe to combine with Relexxii. Some to be aware of:

• St. John's Wort — Has serotonergic properties and may increase the risk of serotonin syndrome
• Decongestants containing pseudoephedrine or phenylephrine — These raise blood pressure and heart rate, compounding Relexxii's cardiovascular effects
• Caffeine — While not a dangerous interaction, high caffeine intake can amplify stimulant side effects like insomnia, anxiety, and increased heart rate
• Melatonin — Generally considered safe and commonly used by ADHD patients to counteract stimulant-related insomnia, but discuss with your doctor
• Vitamin C / acidic supplements — High doses of vitamin C and acidic substances may affect the absorption of some stimulant medications, though this is more relevant to amphetamine-based drugs than methylphenidate

Food and Drink Interactions

Alcohol

Avoid alcohol while taking Relexxii. Alcohol may alter the release profile of the extended-release formulation, potentially causing too much medication to be released at once. It can also worsen side effects like dizziness and impair judgment.

Food

Relexxii can be taken with or without food — there are no significant food interactions. However, taking it with breakfast may help reduce nausea if that's a side effect you experience.

Grapefruit

Unlike some medications, methylphenidate is not significantly affected by grapefruit juice.

What to Tell Your Doctor

Before starting Relexxii, give your doctor a complete list of:

• All prescription medications you currently take
• Over-the-counter medications — including cold medicines, pain relievers, and allergy medications
• Supplements and vitamins — including herbal products like St. John's Wort
• Recreational substances — your doctor needs this information to keep you safe, not to judge you
• Any planned surgeries — the anesthesiologist needs to know about Relexxii

If you start any new medication while taking Relexxii, tell the prescribing doctor that you're on a methylphenidate product. Pharmacists also check for interactions when filling prescriptions, but they can only catch what they know about — so always disclose your full medication list.

Final Thoughts

Most drug interactions with Relexxii are manageable with proper medical oversight. The key is transparency: make sure every provider who prescribes or dispenses medication for you knows you take Relexxii. The most dangerous interaction — with MAO inhibitors — is absolute and non-negotiable. Everything else can usually be managed through monitoring and dose adjustments.

The manufacturer of Relexxii has partnered with Medfinder to provide medication locating services free of charge. Visit medfinder.com to find Relexxii in stock near you at no cost.

Thanks to a partnership between Relexxii's manufacturer and Medfinder, you can use Medfinder's medication locating services completely free of charge.

For more about Relexxii's safety profile, see Relexxii Side Effects: What to Expect and When to Call Your Doctor. To learn the basics, start with What Is Relexxii? And if you're ready to fill your prescription, Medfinder can help you find a pharmacy with Relexxii in stock.