Genetic Implications: Genetic Implications


Trade Name(s)

  • Movantik

Ther. Class.

Pharm. Class.
opioid antagonists


Treatment of opioid-induced constipation (OIC) in patients with chronic non-cancer pain, including those with chronic pain related to prior cancer or its treatment who do not require frequent (e.g., weekly) opioid dose escalation.


Acts peripherally as a mu receptor antagonist, blocking opioid receptors in the GI tract.

Therapeutic Effect(s):

Blocks constipating effects of opioids on the GI tract without loss of analgesia.


Absorption: Systemic absorption follows oral administration. A high-fat meal ↑ absorption.

Distribution: Does not cross the blood-brain barrier.

Metabolism and Excretion: Metabolized primarily by the CYP3A4 enzyme system; 68% excreted in feces, 16% in urine mostly as metabolites.

Half-life: 6–11 hr.

TIME/ACTION PROFILE (spontaneous bowel movement)

POwithin 24 hrunknownunknown


Contraindicated in:

  • Hypersensitivity;
  • Known/suspected/history of GI obstruction;
  • Severe hepatic impairment;
  • Concurrent use of strong CYP3A4 inhibitors, strong CYP3A4 inducers, or other opioid antagonists;
  • Severe hepatic impairment;
  • Lactation: May precipitate opioid withdrawal in infant.

Use Cautiously in:

  • Patients with disruption of the blood-brain barrier (may precipitate opioid withdrawal);
  • OB:  Use only if potential maternal benefit justifies potential fetal risk (may precipitate fetal opioid withdrawal);
  • Pedi:   Safety and effectiveness not established
  • Geri:  Genetic implication  Blood levels are ↑ in elderly Japanese patients.

Adverse Reactions/Side Effects

CNS: headache

Derm: sweating

GI: GASTROINTESTINAL PERFORATION, abdominal pain, diarrhea, flatulence, nausea, vomiting


* CAPITALS indicate life-threatening.
Underline indicate most frequent.



  • Strong CYP3A4 inhibitors, including  clarithromycin  and  ketoconazole  may ↑ risk of toxicity/adverse reactions; concurrent use contraindicated.
  • Strong CYP3A4 inducers, including rifampin , may ↓ blood levels/effectiveness; concurrent use contraindicated.
  • Other  opioid antagonists  may precipitate opioid withdrawal; concurrent use contraindicated.
  • Moderate CYP3A4 inhibitors, including diltiazem, erythromycin, and verapamil , may ↑ risk of toxicity/adverse reactions; ↓ dose of methylnaltrexone.
  • Concurrent use of  methadone  for pain ↑ risk of stomach pain and diarrhea.


Grapefruit/grapefruit juice may ↑ blood levels and the risk of toxicity/adverse reactions; avoid concurrent use.


PO (Adults): 25 mg once daily; if poorly tolerated ↓ dose to 12.5 mg once daily;  Concurrent use of moderate CYP3A4 inhibitors– 12.5 mg once daily (careful monitoring recommended).

Renal Impairment 
PO (Adults):  CCr <60 mL/min– 12.5 mg once daily initially; may cautiously ↑ to 25 mg once daily, if necessary, with careful monitoring.


Tablets: 12.5 mg, 25 mg


  • Assess bowel sounds and frequency, quantity, and consistency of stools periodically during therapy.
  • Monitor pain intensity during therapy. Naloxegol does not affect pain or effects of opioid analgesics on pain control. Discontinue naloxegol if opioid analgesic is discontinued.
  • Monitor for signs and symptoms of gastrointestinal perforation (severe, persistent or worsening abdominal pain) periodically during therapy. Discontinue naloxegol if symptoms occur.

Potential Diagnoses


  • Discontinue all maintenance laxative therapy before starting naloxegol. If a suboptimal response occurs with naloxegol, laxatives may be used after 3 days.
  • PO Administer on an empty stomach at least 1 hr before first meal in morning or 2 hrs after meal. Tablet may be crushed to a powder, mixed with 4 oz of water (120 mL) for patients with difficulty swallowing. Drink mixture immediately; refill glass with 120 mL water, stir and drink contents.
    • May be administered by NG tube. Flush the NG tube with 1 oz (30 mL) of water using a 60 mL syringe. Crush tablet to a powder and mix with 2 oz (60 mL) of water. Draw up mixture using the 60 mL syringe and administer through the NG tube. Add 2 oz (60 mL) of water to rinse container and administer to flush NG tube and any remaining medicine from NG tube into stomach.
    • Avoid grapefruit and grapefruit juice during therapy.

Patient/Family Teaching

  • Instruct patient to take naloxegol on an empty stomach as directed. Laxatives should be stopped before starting naloxegol, but may be restarted after 3 days if needed. Advise patient to read the  Medication Guide  prior to starting therapy and with each Rx refill in case of changes.
  • Caution patient to avoid grapefruit and grapefruit juice during therapy.
  • Advise patient to notify health care professional immediately if stomach pain that does not go away occurs.
  • Advise patient to notify health care professional if signs and symptoms of opioid withdrawal (sweating, chills, diarrhea, stomach pain, anxiety, irritability, yawning) occur. Patients taking methadone for pain are at increased risk for stomach pain and diarrhea.
  • Instruct patient to stop taking naloxegol if they stop taking opioid medications.
  • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications.
  • Advise female patients to notify health care professional if pregnancy is planned or suspected and avoid breast feeding during therapy; may cause opioid withdrawal in infant.

Evaluation/Desired Outcomes

Relief of OIC, especially if opioid therapy has been for 4 wk or more.

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