naloxegol

naloxegol

(nal-ox-ee-gol),

Movantik

(trade name)

Classification

Therapeutic: laxatives
Pharmacologic: opioid antagonists
Pregnancy Category: C

Indications

Treatment of opioid-caused constipation (OIC) in patients receiving chronic opioids for chronic non-cancer pain when traditional laxatives have failed.

Action

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

Therapeutic effects

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

Pharmacokinetics

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)

ROUTEONSETPEAKDURATION
POwithin 24 hrunknownunknown

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Known/suspected/history of gastrointestinal obstruction; Severe hepatic impairment; Concurrent use of strong CYP3A4 inhibitors, strong CYP3A4 inducers, other opioid antagonists or grapefruit/grapefruit juice; 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); Geriatric: Blood levels are ↑ in elderly Japanese patients; Obstetric: May precipitate fetal opioid withdrawal (use only if potential benefit justifies potential risk to fetus); Pediatric: Safe and effective use in children has not been established.

Adverse Reactions/Side Effects

Central nervous system

  • headache

Gastrointestinal

  • gastrointestinal perforation (life-threatening)
  • abdominal pain (most frequent)
  • diarrhea
  • flatulence
  • nausea
  • vomiting

Dermatologic

  • sweating

Miscellaneous

  • opioid withdrawal

Interactions

Drug-Drug interaction

Concurrent use of strong CYP3A4 inhibitors including clarithromycin and ketoconazole ↑ risk of toxicity/adverse reactions and is contraindicated.Concurrent use of moderate CYP3A4 inhibitors including diltiazem, erythromycin, and verapamil may also↑ risk of toxicity/adverse reactions; dose reduction and careful monitoring recommended.Concurrent use of strong CYP3A4 inducers including rifampin may ↓ blood levels/effectiveness and is contraindicated.Concurrent use of other opioid antagonists may precipitate opioid withdrawal and is contraindicated.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 and should be avoided.

Route/Dosage

Oral (Adults) 25 mg once daily, if poorly tolerated decrease dose to 12.5 mg; concurrent use of moderate CYP3A4 inhibitors—12.5 mg daily (careful monitoring recommended).

Renal Impairment

Oral (Adults) CCr <60 mL/min—12.5 mg daily initially, may be cautiously increased to 25 mg/day if necessary with careful monitoring.

Availability

Tablets: 12.5 mg, 25 mg

Nursing implications

Nursing assessment

  • 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 Nursing Diagnoses

Constipation (Indications)
Diarrhea (Adverse Reactions)

Implementation

  • Discontinue all maintenance laxative therapy before starting naloxegol. If a suboptimal response occurs with naloxegol, laxatives may be used after 3 days.
  • Oral: Administer on an empty stomach at least 1 hr before first meal in morning or 2 hrs after meal. Swallow tablet whole; do not break, crush, or chew.
    • 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 Medication Guide prior to starting therapy and with each 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 or if breastfeeding.

Evaluation/Desired Outcomes

  • Relief of opioid induced constipation, especially if opioid therapy has been for 4 wks or more.