Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Movantik (Naloxegol). If you are concerned about side effects, discuss the risks and benefits of Movantik (Naloxegol) with your doctor.

The following side effects have been reported by at least 1% of people taking Movantik (Naloxegol). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• Diarrhea
• excessive sweating
• headache
• nausea
• passing gas
• runny or stuffy nose
• stomach pain
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• symptoms of opioid withdrawal (e.g., nausea, vomiting, diarrhea, excess sweating, muscle aches, increased tearing, Insomnia, yawning)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• severe or persistent stomach pain
• severe diarrhea (watery, bloody, or persistent)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Movantik (Naloxegol).

12.5 mg
Each oval, biconvex, mauve, film-coated tablet, intagliated with "12.5" on one side and "nGL" on the other, contains 12.5 mg of Movantik (Naloxegol). Nonmedicinal ingredients: mannitol, microcrystalline cellulose, croscarmellose sodium, propyl gallate, and magnesium stearate. Tablet coating: hypromellose, titanium dioxide, macrogol 400, iron oxide red, and iron oxide black.

25 mg
Each oval, biconvex, mauve, film-coated tablet, intagliated with "25" on one side and "nGL" on the other, contains 25 mg of Movantik (Naloxegol). Nonmedicinal ingredients: mannitol, microcrystalline cellulose, croscarmellose sodium, propyl gallate, and magnesium stearate. Tablet coating: hypromellose, titanium dioxide, macrogol 400, iron oxide red, and iron oxide black.

Do not take Movantik (Naloxegol) if you:

• are allergic to Movantik (Naloxegol) or any ingredients of the medication
• have or may have a blockage in the digestive tract
• have a history of blockage in the digestive tract
• are taking any of the following medications:
• "azole" antifungals (e.g., ketoconazole, Voriconazole)
• HIV protease inhibitors (e.g., ritonavir, lopinavir)
• macrolide antibiotics (e.g., clarithromycin, erythromycin)

There may be an interaction between Movantik (Naloxegol) and any of the following:

• Abiraterone acetate
• Amiodarone
• Aprepitant
• Atorvastatin
• "azole" antifungals (e.g., itraconazole, ketoconazole, voriconazole)
• boceprevir
• Bosentan
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• Carbamazepine
• Cobicistat
• conivaptan
• Cyclosporine
• daclatasvir
• Deferasirox
• Dronedarone
• Enzalutamide
• Eslicarbazepine
• grapefruit juice
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delavirdine, efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• ledipasvir        
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• Methadone
• Methylnaltrexone
• mifepristone
• Mitotane
• Modafinil
• Naloxone
• Naltrexone
• nefazodone
• Phenobarbital
• Phenytoin
• primidone
• certain protein kinase inhibitors (e.g., Crizotinib, Dabrafenib, imatinib, Lapatinib, Nilotinib)
• quinidine
• quinine
• rifabutin
• rifampin
• St. John's wort
• simeprevir
• Stiripentol
• Tocilizumab

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Movantik (Naloxegol). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Movantik (Naloxegol).

Gastrointestinal perforation: People with advanced illness who use Movantik (Naloxegol) may be at increased risk of gastrointestinal perforation (a hole that forms in the wall of the gastrointestinal tract, such as through the stomach or intestines). People are especially at risk if they also have a weakened gastrointestinal wall due to conditions such as cancer, intestinal cancer, or gastrointestinal cancer. If you experience severe, worsening, or persistent abdominal pain that's intensified by movement, or accompanied by Fever, chills, nausea or vomiting, seek immediate medical attention. These could be symptoms of gastrointestinal perforation, which is a medical emergency.

Kidney Function: Kidney Disease or reduced kidney function may cause Movantik (Naloxegol) to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how Movantik (Naloxegol) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Movantik (Naloxegol), and whether any special monitoring is needed.

Opioid withdrawal: Very rarely, Movantik (Naloxegol) may block the effects of opioids on the nervous system. This can result in symptoms of withdrawal. If you experience unusual sweating, mood swings, nausea or vomiting, muscle aches, tearing, diarrhea, yawning, or difficulty sleeping, contact your doctor.

Pregnancy: Movantik (Naloxegol) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Movantik (Naloxegol), contact your doctor immediately.

Breast-feeding: It is not known if Movantik (Naloxegol) passes into breast milk. If you are a breast-feeding mother and are taking Movantik (Naloxegol), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Movantik (Naloxegol) have not been established for children.