Why is this medication prescribed?

Methylnaltrexone is a medication that is primarily prescribed for the management of opioid-induced constipation (OIC) in adults with chronic non-cancer pain, as well as for those with advanced illness who are receiving palliative care. Opioid medications, commonly used for pain relief, can often lead to constipation as a side effect. Methylnaltrexone works by blocking the effects of opioids in the gut without affecting their pain-relieving properties in the central nervous system, thus helping to alleviate constipation caused by opioids.

How should this medicine be used?

Here are some key points on how Methylnaltrexone is used:

• Prescription: Methylnaltrexone should be prescribed by a healthcare professional, usually a doctor who is familiar with your medical history and needs.
• Administration: It is typically administered as a subcutaneous (under the skin) injection or, less commonly, as an oral tablet. The choice of administration method depends on your specific situation and your healthcare provider’s recommendation.
• Dosage: The dosage of Methylnaltrexone can vary depending on the individual’s response to opioids and the severity of constipation. Your healthcare provider will determine the appropriate dose for you.
• Timing: Methylnaltrexone is usually taken as needed, depending on the occurrence of opioid-induced constipation. Your doctor will provide guidance on when and how often to take it.
• Follow Instructions: It is essential to follow your healthcare provider’s instructions carefully. Do not use Methylnaltrexone more frequently or in higher doses than prescribed, as this can lead to complications or reduced opioid pain relief.
• Side Effects: Like any medication, Methylnaltrexone can have side effects. Common side effects may include abdominal pain, diarrhea, nausea, and sweating. If you experience any severe or unusual side effects, contact your healthcare provider.
• Monitoring: Your healthcare provider may monitor your response to Methylnaltrexone and adjust the dosage or treatment plan as needed.
• Other Medications: Inform your healthcare provider about any other medications you are taking, as some drug interactions may occur with Methylnaltrexone.
• Lifestyle Modifications: Along with taking Methylnaltrexone, it’s important to maintain a healthy diet, stay hydrated, and engage in physical activity as appropriate to help manage constipation.

Remember that Methylnaltrexone is specifically designed to address opioid-induced constipation and should not be used as a replacement for opioid pain medications or to treat other types of constipation. Always consult with your healthcare provider for personalized guidance on its use and potential alternatives.

Other uses for this medicine

While Methylnaltrexone is primarily indicated for OIC, it may have some potential off-label uses or investigational applications. However, these should be discussed with a healthcare provider, and the efficacy and safety in these alternative uses may not be well-established. Some potential off-label uses include:

• Management of opioid withdrawal symptoms.
• Treatment of opioid use disorder (OUD), often as part of a comprehensive treatment plan.
• Investigational use in conditions associated with gut motility disorders.

What special precautions should I follow?

When using Methylnaltrexone, it’s essential to take certain precautions to ensure its safe and effective use:

• Medical History: Inform your healthcare provider about your complete medical history, including any allergies, underlying medical conditions, and a history of gastrointestinal disorders or surgeries.
• Medication Interaction: Let your healthcare provider know about all the medications, supplements, and herbal products you are taking, especially other opioid medications, as drug interactions may occur.
• Pregnancy and Breastfeeding: If you are pregnant, planning to become pregnant, or breastfeeding, discuss the potential risks and benefits of Methylnaltrexone with your healthcare provider. The use of Methylnaltrexone during pregnancy or breastfeeding should be carefully considered.
• Allergic Reactions: Report any signs of an allergic reaction (e.g., rash, itching, swelling, severe dizziness, difficulty breathing) to your healthcare provider immediately.
• Monitoring: Your healthcare provider may monitor your response to Methylnaltrexone and adjust the treatment plan as needed. Regular follow-up appointments may be recommended.
• Side Effects: Be aware of potential side effects, including abdominal pain, diarrhea, nausea, and sweating, and promptly report any severe or unusual side effects to your healthcare provider.
• Opioid Pain Relief: Methylnaltrexone is designed to address constipation without affecting the pain-relieving properties of opioids. Do not use it to replace your opioid pain medication.
• Use as Directed: Follow your healthcare provider’s instructions carefully regarding the timing, dosage, and administration method of Methylnaltrexone.

Always consult with your healthcare provider for personalized advice and precautions related to the use of Methylnaltrexone, especially if you have concerns or are considering its use for off-label purposes. Your healthcare provider can assess whether it is an appropriate option for your specific medical condition and needs.

What special dietary instructions should I follow?

Special Dietary Instructions for Methylnaltrexone:

• Take Methylnaltrexone with or without food: Methylnaltrexone can be taken with or without food. It does not typically interact with food, so you do not need to follow any specific dietary restrictions in terms of what you eat when taking this medication.
• Stay hydrated: Opioid-induced constipation can be exacerbated by dehydration. Ensure you are drinking an adequate amount of fluids daily to help manage constipation.
• Fiber-rich diet: While there are no specific dietary restrictions associated with Methylnaltrexone, maintaining a diet rich in fiber can help alleviate constipation. Foods high in fiber include fruits, vegetables, whole grains, and legumes.

What should I do if I forget a dose?

If you forget to take a dose of Methylnaltrexone, follow these general guidelines:

• Take the missed dose as soon as you remember: If it’s close to the time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not take extra doses to make up for the missed one.
• Notify your healthcare provider: If you frequently forget doses or have concerns about missed doses, discuss this with your healthcare provider. They can provide guidance on how to manage missed doses effectively.
• Maintain your regular dosing schedule: To ensure the medication works as intended, it’s essential to take it consistently and as prescribed by your healthcare provider. Consistency will help manage opioid-induced constipation effectively.

What side effects can this medication cause?

Methylnaltrexone, like any medication, can cause side effects. Not everyone will experience these side effects, and their severity can vary from person to person. It’s important to discuss potential side effects and any concerns with your healthcare provider before starting Methylnaltrexone. Common side effects of Methylnaltrexone may include:

• Abdominal Pain: This is one of the most commonly reported side effects of Methylnaltrexone. It can range from mild discomfort to more severe abdominal pain.
• Diarrhea: Diarrhea is another common side effect and is often associated with the mechanism of action of Methylnaltrexone, which promotes bowel movements.
• Nausea: Some individuals may experience feelings of nausea after taking Methylnaltrexone.
• Sweating: Excessive sweating, often accompanied by warm or flushed skin, has been reported as a side effect.
• Chills: Some people may experience chills or shivering as a side effect.
• Body Aches: Muscular discomfort or body aches may occur in some individuals.
• Dizziness: Methylnaltrexone can sometimes lead to dizziness or lightheadedness.
• Headache: Headaches have been reported as a side effect, although they are less common.
• Vomiting: While less common, some individuals may experience vomiting as a side effect.
• Dehydration: Diarrhea and increased bowel movements can potentially lead to dehydration, so it’s important to stay adequately hydrated while using Methylnaltrexone.

It’s essential to note that while these side effects can occur, Methylnaltrexone is generally well-tolerated, especially when used as directed for the management of opioid-induced constipation. Most side effects are mild to moderate in severity and tend to resolve on their own.

However, if you experience severe or persistent side effects, it’s crucial to contact your healthcare provider promptly. Additionally, if you notice any signs of an allergic reaction, such as rash, itching, swelling, severe dizziness, or difficulty breathing, seek immediate medical attention.

Your healthcare provider will assess the risks and benefits of Methylnaltrexone for your specific situation and can provide guidance on managing any side effects that may occur during treatment. They may also adjust your dosage or treatment plan if necessary.

What should I know about storage and disposal of this medication?

Storage of Methylnaltrexone:

• Store Methylnaltrexone at room temperature, away from excess heat and moisture.
• Keep the medication out of the reach of children and pets.
• Do not store it in the bathroom or any area with high humidity.

Disposal of Methylnaltrexone:

• Do not flush Methylnaltrexone down the toilet or pour it down the drain unless instructed to do so by your healthcare provider or pharmacist.
• Follow any specific disposal instructions provided with the medication, if available.
• If you are unsure about how to dispose of unused or expired Methylnaltrexone, consult your local pharmacy or healthcare provider for guidance. Some areas have specific guidelines for medication disposal.

In case of emergency/overdose

• If you suspect an overdose or experience severe side effects after taking Methylnaltrexone, seek immediate medical attention or call your local poison control center at once.
• Be prepared to provide information about the medication, the dose taken, and any symptoms or reactions you are experiencing.

What other information should I know

• Methylnaltrexone is a medication used to treat opioid-induced constipation (OIC) in adults who are receiving opioid therapy for chronic non-cancer pain. It works by blocking the effects of opioids in the gut without affecting their pain-relieving effects on the central nervous system.
• Follow your healthcare provider’s instructions carefully regarding the dosage and administration of Methylnaltrexone.
• Inform your healthcare provider about any other medications, supplements, or medical conditions you have, as there may be interactions or contraindications with Methylnaltrexone.
• Be aware of potential side effects, which may include abdominal pain, nausea, diarrhea, sweating, chills, and more. Report any unusual or severe side effects to your healthcare provider.
• Do not use Methylnaltrexone if you are allergic to it or if you have a bowel blockage (mechanical gastrointestinal obstruction).
• Methylnaltrexone is not meant to be a treatment for opioid addiction or to reverse opioid overdose. It is specifically for managing opioid-induced constipation.

Always consult with your healthcare provider or pharmacist for personalized information and guidance related to Methylnaltrexone, as individual circumstances may vary, and they can provide the most up-to-date information.