Naloxegol (Oral)

As a peripherally selective opioid antagonist, Naloxegol is used to treat constipation caused by long-term use of narcotic pain medication.


When patients suffer from chronic conditions, they may be required to take strong pain medication. Although narcotic painkillers can be effective in reducing the patient's pain and discomfort, they can cause a number of side effects. Often, patients experience more side effects when they first start taking opioid pain medicines but these diminish as their body becomes accustomed to the medication.

Constipation is one of the most common side effects of treatment with opioid pain medication and affects numerous patients. The use of narcotic pain medicines slows down gastrointestinal motility and transit, meaning that patients are unable to open their bowels or pass stools. Unlike other side effects, opioid-induced constipation (OIC) does not tend to diminish over time and patients may experience this side effect throughout the course of their treatment.

Due to the seriousness of opioid-induced constipation, patients are usually treated with additional medication. When Naloxegol is used to treat the condition, patients are still able to obtain pain relief via medication but do not suffer from severe constipation. As a result, treatment with pain medication does not necessarily need to be discontinued.

As Naloxegol acts as an opioid receptor antagonist on bodily tissues, such as in the gastrointestinal tract, it reduces the constipating effects of narcotic pain medication. Unlike some other opioid receptor antagonists, Naloxegol does not cross the blood-brain barrier and does not impact upon the central nervous system. Due to this, Naloxegol can be used to successfully relieve OIC on a long-term basis.

Opioid pain medications are typically used to treat severe pain and there are a number of conditions which can result in long-term treatment with this type of medication. Although Naloxegol can be used to treat patients who are taking narcotic pain medicines for various conditions, it should not be prescribed to patients who have long-lasting pain caused by cancer. Providing the patient's pain is caused by another factor, Naloxegol may be used to reduce opioid-induced constipation caused by the on-going use of narcotic pain medication.

Conditions Treated

  • Opioid-induced constipation (OIC)

Type Of Medicine

  • Peripherally selective opioid antagonist

Side Effects

Like most medications, Naloxegol can cause patients to experience some unwanted effects. Often, side effects are more common when patients first start using Naloxegol but these may be reduced over time.

For example, patients may experience the following side effects when taking Naloxegol:

  • Bloating
  • Headache
  • Excess gas or air in the bowels or stomach
  • Vomiting
  • Passing gas
  • Full feeling

If the above side effects are not severe and are not bothersome to the patient, additional medical treatment may not be required. However, if the patient's side effects do not subside or if they are particularly serious, patients should seek medical help.

In addition to this, patients should inform their doctor immediately if they develop the following side effects when taking Naloxegol:

  • Stomach or abdominal pain
  • Anxiety
  • Tarry, black or bloody stools
  • Chills
  • Irritability
  • Diarrhea
  • Yawning
  • Increased sweating
  • Heartburn
  • Nausea
  • Indigestion
  • Trouble with breathing
  • Vomiting of material that looks like coffee grounds, may be severe and continuing
  • Severe stomach or abdominal, burning, pain or cramping

Patients should also seek medical help or assistance if they experience any other side effects when taking Naloxegol.


When patients are prescribed Naloxegol tablets, they should follow their doctor's instructions and only take the medication as they have been advised to. In general, adult patients who are prescribed Naloxegol are instructed to take 25mg, once per day. This medication is usually taken in the morning and should be taken on an empty stomach, at least one hour before eating. Alternatively, Naloxegol can be taken at least two hours after eating a meal.

If patients have been taking any other laxatives, they should stop taking them before they start using Naloxegol. In addition to this, patients will usually be advised to stop taking Naloxegol if they discontinue treatment with narcotic pain medication.

If possible, patients should swallow the Naloxegol tablet whole and should not chew it, break it or crush it. However, if patients are unable to swallow the tablet whole, doctors may advise them to crush it into a powder and mix it with approximately 120mL of water. This mixture should be drunk straight away and patients should then add water to the glass, stir it and drink it. By doing this, patients ensure that there is no residue left in the glass and that they get the full dose of medication.

Alternatively, patients who are unable to swallow the Naloxegol tablet whole may be given this medication via a nasogastric tube. In order to do this, patients should draw up 30mL of water into a 60mL syringe and flush it through. Following this, patients can crush the tablet into powder and mix it in a container with 60mL of water. Patients should then draw the mixture up into a 60mL syringe and administer it through the nasogastric tube. A further 60mL of water can be added to the container and flushed through the syringe to ensure that the patient gets the full dose of Naloxegol. If Naloxegol is to be administered via a nasogastric tube, patients and their caregivers should be taught how to use the equipment before the medication is prescribed to them.

When using Naloxegol, patients should not consume grapefruit, grapefruit juice or any products containing grapefruit as it could interact with the medication and cause them to suffer adverse or harmful effects.

If patients forget to take a dose of Naloxegol, they should do so as soon as they remember. However, if their next dose of medication is due relatively soon, they should skip the missed dose entirely. Patients should not attempt to take an extra or double dose of Naloxegol, even if a previous dose has been missed.

Before taking Naloxegol, patients should ensure that they read the accompanying medication guide. If patients are unsure how or when to take Naloxegol, they should seek advice from their physician or pharmacist.

Potential Drug Interactions

As certain medications can interact with each other, Naloxegol should not be prescribed in conjunction with any of the following:

  • Atazanavir
  • Nefazodone
  • Boceprevir
  • Posaconazole
  • Clarithromycin
  • Lopinavir
  • Cobicistat
  • Nelfinavir
  • Conivaptan
  • Ketoconazole
  • Delavirdine
  • Telithromycin
  • Idelalisib
  • Telaprevir
  • Indinavir
  • Tipranavir
  • Itraconazole
  • Saquinavir
  • Ritonavir
  • Voriconazole

Similarly, Naloxegol is not usually recommended for use alongside any of the following medicines:

  • Abiraterone
  • Methylnaltrexone
  • Alvimopan
  • Netupitant
  • Aprepitant
  • Naloxone
  • Carbamazepine
  • Naltrexone
  • Ceritinib
  • Nalmefene
  • Ciprofloxacin
  • Nalorphine
  • Crizotinib
  • Nilotinib
  • Darunavir
  • Mitotane
  • Diltiazem
  • Oxcarbazepine
  • Dronedarone
  • Mifepristone
  • Efavirenz
  • Phenytoin
  • Enzalutamide
  • Rifabutin
  • Erythromycin
  • Miconazole
  • Etravirine
  • Primidone
  • Fluconazole
  • Rifampin
  • Fosaprepitant
  • Rifapentine
  • Fosphenytoin
  • St John's Wort
  • Imatinib
  • Verapamil
  • Ticagrelor
  • Samidorphan

In some cases, however, it may be necessary to prescribe Naloxegol alongside one of the medications listed above. If so, the patient's dose may be modified to try and prevent an interaction occurring.

Naloxegol can also interact with the following food and drink and patients should not, therefore, consume these substances when taking Naloxegol:

  • Grapefruit, grapefruit juice or any other products containing grapefruit

Before taking Naloxegol, patients should tell their physician if they are taking any other medicines, vitamins or supplements. Patients should also obtain medical advice before using any new medications, supplements or vitamins once they have started taking Naloxegol.


If patients have any other medical conditions, they should discuss them with their doctor before taking Naloxegol. There are some conditions which can affect treatment with Naloxegol and these may include:

To date, specific studies on the effects of Naloxegol on pediatric patients have not been carried out. Due to this, children and infants may not be treated with Naloxegol.

When patients are taking Naloxegol, they should have regular consultations with their physician. This will enable their doctor to ensure that the medication is working properly and to alter their dose if required. In addition to this, physicians can ensure that Naloxegol is not having any unwanted effects.

Patients should not take any other medications when using Naloxegol unless their doctor has instructed them to. Taking Itraconazole, Ketoconazole and/or Clarithromycin alongside Naloxegol can cause or worsen withdrawal symptoms from opioids. These symptoms could include:

  • Chills
  • Anxiety
  • Irritability
  • Diarrhea
  • Sweating
  • Yawning
  • Stomach pain

When taking Naloxegol, patients may develop a tear or perforation in their bowels or stomach. If patients have severe stomach pain which does not go away, they should obtain urgent medical treatment.

Similarly, patients should notify their doctor immediately if they experience the following symptoms when taking Naloxegol:

  • Severe stomach pain
  • Diarrhea

Naloxegol should be used with caution during pregnancy and patients may be advised not to take this medication when pregnant. As a category C medication, Naloxegol could cause harm to an unborn fetus and the benefits must be weighed against the risks when treating patients who are pregnant.

If patients become pregnant when taking Naloxegol, they should inform their physician straight away.

As Naloxegol is only usually taken in conjunction with narcotic pain medication, the patient's other medicines may prevent the patient from breastfeeding due to risks to the infant. Although it's unclear whether Naloxegol is excreted in breast milk, patients are typically advised to discontinue breastfeeding when taking this medication. If Naloxegol is excreted in breast milk, it could cause harm to an infant if transferred via breastfeeding. Patients should obtain medical advice if they are considering breastfeeding whilst taking Naloxegol.

If patients have any allergies, they should notify their doctor before they start taking Naloxegol. In rare cases, patients may exhibit an allergic reaction when taking this medication and, if so, they will require urgent medical treatment. Serious allergic reactions can be life-threatening so it is vital that patients access emergency medical care if they exhibit the following symptoms:

  • Difficulty breathing
  • Wheezing
  • Hives
  • Difficulty swallowing
  • Itching
  • Hoarseness
  • Swelling of the face, lips, mouth, tongue, throat or hands
  • Shortness of breath


As patients are usually advised to take Naloxegol on a daily basis, they will need to keep a supply of medicine at home. However, patients should show extreme caution when storing Naloxegol at home and should ensure that children and/or pets cannot gain access to it.

In order to store Naloxegol properly, patients should follow the medication guide which accompanies their tablets. In general, Naloxegol can be stored at room temperature but must be kept in a closed container. If Naloxegol tablets are supplied in blister packs, the tablets should remain in the original packaging and should only be removed when the patient is ready to take their next dose of medication.

In addition to this, Naloxegol should be protected from light, heat and moisture.

If patients are advised to stop using Naloxegol or if their medicine reaches its expiration date, patients should dispose of it carefully. Medication, such as Naloxegol, should not be thrown out with regular household waste as it may pose a risk to other people. Instead, patients should contact their physician's office or pharmacist and make use of a specialist medicine disposal service.


Although narcotic pain medicines are effective in treating long-term moderate and severe pain, they can cause the patient to develop a number of side-effects. Opioid-induced constipation is a common side-effect of treatment with narcotic pain relievers and does not tend to diminish over time unless additional treatment is given.

By prescribing Naloxegol, physicians can treat the patient's condition and ensure that they are able to continue taking narcotic pain medication without experiencing opioid-induced constipation. As Naloxegol prevents gastrointestinal motility and transit from being reduced by opioid medication, the subsequent side effect of constipation does not occur.

Without treatment, opioid-induced constipation can cause serious health complications and may result in the patient's treatment being discontinued. However, patients who warrant treatment with narcotic pain medication typically have chronic, moderate or severe pain and require medical intervention. When used appropriately, Naloxegol relieves opioid-induced constipation and facilitates the patient's treatment with narcotic pain relievers.