Methylnaltrexone bromide

ATC code

A06AH01

Therapeutic class

Peripherally acting opioid receptor antagonist · PAMORA

Forms

Subcutaneous injection, Oral tablets

Brand names

Relistor (ES)

Overall confidence

high

Regulatory sources consulted

Approved indications

Opioid-induced constipation in adults when response to laxatives has been inadequate.

Contraindications

Absolute

Known or suspected gastrointestinal obstruction, high risk of recurrent obstruction, or acute surgical abdomen.

Clinical warnings

Major warning · Gastrointestinal perforation, opioid-withdrawal symptoms, and severe or persistent diarrhea have been reported. Stop treatment and seek advice for severe or persistent diarrhea; severe or persistent abdominal pain requires urgent assessment. — CIMA AEMPS / FDA label

Drug interactions

HighOther opioid antagonists
Mechanism: Antagonist effects may be additive and increase the risk of opioid withdrawal.
Recommendation: Avoid concomitant use.
DailyMed Relistor

Adverse events

Common (≥1%)

Abdominal pain · Nausea · Diarrhea

Rare but serious

Gastrointestinal perforation · Opioid withdrawal