• Constipation and bowel cleansers

Relistor Generic Name & Formulations

General Description

Methylnaltrexone bromide 150mg; tabs.

Pharmacological Class

Opioid antagonist (peripheral).

How Supplied

Tabs—60, 90; Single-use vial (12mg/0.6mL)—1; Prefilled syringes (8mg/0.4mL)—7; Prefilled syringes (12mg/0.6mL)—1, 7

Generic Availability


Relistor Indications


Opioid-induced constipation (OIC) in adults with chronic non-cancer pain, including chronic pain related to prior cancer or its treatment in patients who do not require frequent opioid dosage escalation.

Relistor Dosage and Administration


Discontinue all maintenance laxatives prior to initiation; may be used if suboptimal methylnaltrexone response after 3 days. Reevaluate if opioid regimen is changed. Take on an empty stomach with water ≥30mins before first meal of day. 450mg once daily in the AM. Moderate or severe renal (CrCl<60mL/min) or hepatic (Child-Pugh B or C) impairment: 150mg once daily.


Not established.

Relistor Contraindications


Known or suspected GI obstruction and at increased risk of recurrent obstruction.

Relistor Boxed Warnings

Not Applicable

Relistor Warnings/Precautions


Discontinue if concurrent opioid pain medication is also discontinued. GI perforation; monitor for severe, persistent, or worsening abdominal pain; discontinue if occurs. Discontinue if severe or persistent diarrhea occurs. Increased risk of opioid withdrawal and/or reduced analgesia in those with blood-brain barrier disruptions; monitor for symptoms. Bowel movement may occur within 30 mins of dosing. Elderly. Pregnancy. Nursing mothers: not recommended.

Relistor Pharmacokinetics

See Literature

Relistor Interactions


Potential additive effects and increased risk of opioid withdrawal with concomitant other opioid antagonists; avoid.

Relistor Adverse Reactions

Adverse Reactions

Abdominal pain, flatulence, nausea, dizziness, diarrhea, headache, abdominal distention, vomiting, hyperhidrosis, anxiety, muscle spasms, rhinorrhea, chills, tremor, hot flush; GI perforation, opioid withdrawal.

Relistor Clinical Trials

See Literature

Relistor Note

Not Applicable

Relistor Patient Counseling

See Literature