Gastroenterology Book


Gastrointestinal Opioid Antagonist

Aka: Gastrointestinal Opioid Antagonist, Methylnatrexone, Relistor, Movantik, Naloxegol, Symproic, Nalmedemedine, Alvimopan, Entereg
  1. See Also
    1. Opioid Adverse Effect Management
    2. Bowel Regimen in Chronic Narcotic Use
    3. Amatiza (Lubiprostone)
  2. Indications
    1. Severe refractory Constipation due to Opioids
  3. Mechanism
    1. Block Opioid binding in the intestinal tract
    2. Decreases mu-Opioid receptor mediated bowel paralysis
  4. Preparations
    1. Movantik (Naloxegol) once daily orally in morning ($10/day)
      1. Approved for non-cancer, Opioid-Induced Constipation
      2. Requires Renal Dosing adjustment
      3. Chey (2014) N Engl J Med 370:2387-96 [PubMed]
    2. Methylnaltrexone (Relistor) injection ($70/day)
      1. Methylnaltrexone 5 mg or 0.15 mg/kg SQ
      2. Weight-based SQ Injection once or twice daily
      3. Diarrhea occurs in 8% and Abdominal Pain in 13%
      4. Requires Renal Dosing adjustment
    3. Symproic (Nalmedemedine)
      1. Dose: Once daily
      2. No renal dose adjustment needed
    4. Alvimopan (Entereg)
      1. Approved only for short-term management of post-operative ileus
      2. Restricted prescribing due to risk of Myocardial Infarction
  5. Advantages
    1. Does not cross blood-brain barrier
  6. Disadvantages
    1. All agents in this class are expensive as of 2017 (costs range between $10 to $70 per day)
  7. Efficacy
    1. In general, results in one more Bowel Movement per week
    2. Terminally ill patients
      1. Bowel Movement occurs within 4 hours of dose in 48% of patients (15% wiith Placebo)
      2. Median time to Bowel Movement is 45 minutes (>6 hours for Placebo)
  8. References
    1. (2017) Presc Lett 24(12): 70
    2. Portenoy (2008) J Pain Symptom Manage 35(5): 458-68 [PubMed]
    3. Thomas (2008) N Engl J Med 358(22): 2332-43 [PubMed]
Medication Costs
relistor (on 5/17/2017 at Medicaid.Gov Pharmacy Drug pricing)
RELISTOR 12 MG/0.6 ML SYRINGE $159.82 per ml
RELISTOR 150 MG TABLET $15.90 each
movantik (on 2/22/2017 at Medicaid.Gov Pharmacy Drug pricing)
MOVANTIK 12.5 MG TABLET $10.08 each
MOVANTIK 25 MG TABLET $10.04 each
FPNotebook does not benefit financially from showing this medication data or their pharmacy links. This information is provided only to help medical providers and their patients see relative costs. Insurance plans negotiate lower medication prices with suppliers. Prices shown here are out of pocket, non-negotiated rates. See Needy Meds for financial assistance information.

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