Symproic Drug Interactions: What to Avoid and What to Tell Your Doctor

Why Drug Interactions Matter with Symproic

Symproic (Naldemedine) is a prescription medication for opioid-induced constipation (OIC). Like many drugs, it can interact with other medications you're taking. Some interactions can make Symproic less effective, while others can increase your risk of side effects.

Understanding these interactions helps you stay safe and get the most benefit from your treatment. Always tell your doctor and pharmacist about every medication, supplement, and herbal product you take.

How Your Body Processes Symproic

To understand drug interactions, it helps to know how your body breaks down Symproic. Naldemedine is processed (metabolized) primarily by an enzyme called CYP3A4 in your liver. It's also a substrate of P-glycoprotein (P-gp), a protein that helps transport drugs in and out of cells.

Any medication that affects CYP3A4 or P-gp can change how much Naldemedine is in your system — either too much (increasing side effects) or too little (reducing effectiveness).

Medications to Avoid While Taking Symproic

Strong CYP3A4 Inducers — Do Not Take Together

These medications speed up the breakdown of Symproic, which can make it much less effective or even useless. Avoid taking Symproic with:

• Rifampin — An antibiotic used for tuberculosis and other infections
• Carbamazepine (Tegretol) — A seizure and nerve pain medication
• Phenytoin (Dilantin) — A seizure medication
• St. John's Wort — An herbal supplement used for depression

If you need one of these medications, your doctor should consider an alternative OIC treatment. The interaction is significant enough that the FDA labeling says to avoid coadministration.

Other Opioid Antagonists — Do Not Take Together

Taking Symproic with other drugs that block opioid receptors can increase your risk of opioid withdrawal symptoms. Avoid combining Symproic with:

• Naltrexone (Vivitrol, ReVia) — Used for alcohol and opioid dependence
• Naloxone — Used for opioid overdose reversal (note: combination products like Suboxone contain Naloxone)

If you take any form of opioid antagonist, make sure your doctor knows before starting Symproic.

Medications That Require Monitoring

Strong CYP3A4 Inhibitors

These medications slow down the breakdown of Symproic, which can increase Naldemedine levels in your body and raise the risk of side effects like diarrhea and abdominal pain. Your doctor should monitor you closely if you take:

• Itraconazole (Sporanox) — An antifungal medication
• Ketoconazole — An antifungal medication
• Clarithromycin (Biaxin) — An antibiotic
• Ritonavir (Norvir) — An HIV medication often used as a pharmacokinetic booster

Moderate CYP3A4 Inhibitors

These have a smaller effect but still deserve attention:

• Fluconazole (Diflucan) — An antifungal
• Erythromycin — An antibiotic
• Diltiazem (Cardizem) — A blood pressure and heart medication
• Atazanavir (Reyataz) — An HIV medication

P-glycoprotein (P-gp) Inhibitors

P-gp inhibitors can also increase Symproic levels in your body:

• Cyclosporine (Sandimmune, Neoral) — An immunosuppressant used after organ transplants and for autoimmune conditions

Food and Drink Interactions

Grapefruit and Grapefruit Juice

Grapefruit is a well-known CYP3A4 inhibitor. Drinking grapefruit juice or eating grapefruit while taking Symproic can increase Naldemedine levels, potentially worsening side effects like diarrhea, nausea, and abdominal pain.

You don't need to completely eliminate grapefruit from your diet, but it's a good idea to limit your intake and let your doctor know if you consume it regularly.

Other Foods

Symproic can be taken with or without food. There are no other significant food interactions beyond grapefruit.

Over-the-Counter Medications and Supplements

Some OTC products can interact with Symproic:

• St. John's Wort — As mentioned above, this is a strong CYP3A4 inducer. Avoid it completely while taking Symproic.
• Laxatives — While not a direct drug interaction, combining Symproic with stimulant laxatives can increase the risk of diarrhea. Talk to your doctor about which laxatives are safe to use alongside Symproic.

What to Tell Your Doctor Before Starting Symproic

Before your doctor prescribes Symproic, make sure they know about:

• All prescription medications you take, especially antibiotics, antifungals, HIV medications, seizure medications, and immunosuppressants
• All over-the-counter medications and supplements, including herbal products like St. John's Wort
• Any opioid antagonist medications you take or have recently taken
• Whether you regularly eat grapefruit or drink grapefruit juice
• All other OIC treatments you're currently using

Your pharmacist is also a great resource. Every time you fill a new prescription, your pharmacist checks for drug interactions. Don't hesitate to ask them about potential interactions with Symproic.

What Happens If You Have an Interaction?

If you accidentally take a medication that interacts with Symproic:

• With CYP3A4 inhibitors — Watch for increased side effects like diarrhea, nausea, and abdominal pain. Contact your doctor if symptoms are bothersome.
• With CYP3A4 inducers — Symproic may not work as well. Let your doctor know so they can adjust your treatment.
• With opioid antagonists — Watch for withdrawal symptoms like sweating, chills, tremors, fast heartbeat, and agitation. Contact your doctor immediately.

Never stop taking any medication without talking to your doctor first — even if you think there's an interaction.

Related Resources

For more information about Symproic, check out these articles:

• What Is Symproic? Uses, Dosage, and What You Need to Know
• Symproic Side Effects: What to Expect
• How Does Symproic Work? Mechanism of Action Explained
• How to Save Money on Symproic

Key Takeaways

• Avoid taking Symproic with strong CYP3A4 inducers (Rifampin, Carbamazepine, Phenytoin, St. John's Wort) — they make Symproic less effective.
• Avoid combining Symproic with other opioid antagonists (Naltrexone, Naloxone) — this increases withdrawal risk.
• Strong CYP3A4 inhibitors and P-gp inhibitors can increase Symproic levels and side effects — your doctor should monitor you.
• Limit grapefruit juice while taking Symproic.
• Always share your full medication list with your doctor and pharmacist.