Understanding Symproic Side Effects

Symproic (Naldemedine) is a prescription medication that treats opioid-induced constipation (OIC) in adults with chronic non-cancer pain. Like any medication, it can cause side effects. The good news is that most side effects are mild and tend to improve as your body adjusts.

This guide covers the most common side effects, the serious ones to watch for, and when you should call your doctor. If you're new to Symproic, you may also want to read What Is Symproic? Uses, Dosage, and What You Need to Know.

Common Side Effects of Symproic

In clinical trials, the most frequently reported side effects of Symproic included:

• Abdominal pain — Stomach cramping or discomfort, usually mild to moderate
• Diarrhea — The most common side effect, especially in the first few days
• Nausea — A queasy feeling that typically improves over time
• Vomiting — Less common than nausea, but can occur early on
• Gastroenteritis — Stomach inflammation that can cause cramping and loose stools

These side effects make sense when you understand how Symproic works. By blocking opioid receptors in your gut, the medication restores normal bowel function. Your digestive system may need a few days to adjust to this change.

How to Manage Common Side Effects

Most people find that side effects are worst in the first few days and then settle down. Here are some tips to help:

For Diarrhea

• Stay hydrated — drink plenty of water and clear fluids
• Eat bland foods like rice, bananas, toast, and applesauce (the BRAT diet)
• Avoid greasy, spicy, or high-fiber foods until your stomach settles
• If diarrhea is severe or lasts more than two days, call your doctor

For Nausea and Vomiting

• Take Symproic with food if nausea is a problem (it can be taken with or without food)
• Eat smaller, more frequent meals instead of large ones
• Avoid lying down right after taking the medication
• Ginger tea or ginger candies may help settle your stomach

For Abdominal Pain

• A heating pad on your stomach may provide comfort
• Gentle walking can help move gas and ease cramping
• If pain is severe or doesn't improve, contact your doctor

Serious Side Effects to Watch For

While uncommon, Symproic can cause serious side effects that need immediate medical attention.

Gastrointestinal Perforation

This is a rare but serious condition where a hole develops in the wall of your stomach or intestines. The risk is higher if you have:

• Peptic ulcer disease
• Diverticulitis
• Crohn's disease
• GI tract cancers
• Any condition that weakens the GI wall

Call your doctor or go to the emergency room immediately if you experience:

• Severe, sudden abdominal pain
• Fever
• Rigid or board-like abdomen
• Signs of shock (rapid heartbeat, dizziness, cold sweats)

Opioid Withdrawal Symptoms

Because Symproic blocks opioid receptors in the gut, there is a small chance it can trigger withdrawal-like symptoms. Watch for:

• Excessive sweating or chills
• Tremors or shaking
• Fast heartbeat or palpitations
• Agitation or anxiety
• Runny nose or watery eyes
• Vomiting and diarrhea beyond what's normal for the medication

Symproic is designed to work only in the gut without crossing the blood-brain barrier significantly. This means withdrawal symptoms are uncommon, but they can happen. If you notice these symptoms, call your doctor right away.

Who Should Not Take Symproic?

Symproic is not safe for everyone. You should not take Symproic if you have:

• Known or suspected bowel obstruction — A blockage in your intestines
• Severe liver disease (Child-Pugh Class C) — Your body may not process the drug safely
• A history of allergic reaction to Naldemedine or any ingredient in Symproic

You should also tell your doctor if you're pregnant, breastfeeding, or planning to become pregnant. Symproic is not recommended during pregnancy or breastfeeding.

Side Effects vs. Alternatives

All OIC medications can cause GI side effects. Here's how Symproic compares to similar drugs:

• Movantik (Naloxegol) — Similar side effect profile; abdominal pain and diarrhea are most common
• Relistor (Methylnaltrexone) — Can cause injection site reactions (for the subcutaneous form) in addition to GI effects
• Amitiza (Lubiprostone) — More likely to cause nausea; must be taken twice daily with food

If Symproic's side effects are too much for you, your doctor may switch you to a different medication. Learn more in our article on Alternatives to Symproic.

Drug Interactions That Can Increase Side Effects

Certain medications can increase Symproic levels in your body, which may worsen side effects. These include:

• Strong CYP3A4 inhibitors like Itraconazole, Ketoconazole, Clarithromycin, and Ritonavir
• P-glycoprotein inhibitors like Cyclosporine
• Grapefruit juice — Can raise Naldemedine levels

If you take any of these, your doctor should monitor you more closely for side effects. For a full breakdown, see Symproic Drug Interactions: What to Avoid.

When to Call Your Doctor

Contact your doctor if you experience any of the following while taking Symproic:

• Diarrhea that lasts more than two days or is severe
• Severe abdominal pain that doesn't go away
• Signs of opioid withdrawal (sweating, chills, tremors, racing heart)
• Blood in your stool
• Fever along with stomach symptoms
• Any allergic reaction (rash, swelling, trouble breathing)

Go to the emergency room if you have sudden, severe abdominal pain or signs of GI perforation.

Key Takeaways

• The most common Symproic side effects are diarrhea, abdominal pain, and nausea — these usually improve within a few days.
• Serious side effects like GI perforation and opioid withdrawal are rare but require immediate medical attention.
• Manage mild side effects with hydration, bland foods, and timing your dose with meals.
• Tell your doctor about all medications you take to avoid interactions that could worsen side effects.
• Don't stop taking Symproic without talking to your doctor first.