Partial
Partially Aligned
Patient Risk:
Moderate
Summary
The response set includes three claims that are directly supported by the provided FDA label (indications and contraindication). However, many other included claims (e.g., mechanism description, formulation/strength meaning, dosing rationale, and specific adverse-effect types) are not supported or evaluated against the provided label excerpts, so overall alignment is limited.
Category Scores
Accurate Statements
Relistor (methylnaltrexone) is used for opioid-induced constipation in adult patients with chronic non-cancer pain (including certain prior-cancer patients who do not require frequent opioid dosage escalation).
Supported by FDA label section 1.1: “RELISTOR tablets and RELISTOR injection are indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic non-cancer pain, including patients with chronic pain related to prior cancer or its treatment who do not require frequent (e.g., weekly) opioid dosage escalation.”
Methylnaltrexone is used in the opioid-induced constipation setting.
Supported by FDA label sections 1.1 and 1.2 (OIC indication for adult patients in both settings).
Methylnaltrexone is contraindicated in patients with known or suspected gastrointestinal obstruction and patients at increased risk of recurrent obstruction due to potential gastrointestinal perforation.
Supported by FDA label section 4: “RELISTOR is contraindicated in patients with known or suspected gastrointestinal obstruction and patients at increased risk of recurrent obstruction, due to the potential for gastrointestinal perforation …”
Relistor injection is used for opioid-induced constipation in adult patients with advanced illness or pain caused by active cancer requiring opioid dosage escalation for palliative care.
Supported by FDA label section 1.2: “RELISTOR injection is indicated for the treatment of OIC in adult patients with advanced illness or pain caused by active cancer who require opioid dosage escalation for palliative care.”
Unsupported Statements
Relistor 150 usually refers to the 150 mg strength of methylnaltrexone.
Provided label excerpt supports that RELISTOR tablets include a 150 mg tablet strength, but the statement that 'Relistor 150 usually refers to the 150 mg strength' is not explicitly stated in the provided label text (e.g., no explicit naming convention statement).
Methylnaltrexone is a medication used to treat constipation that can occur when people use opioids.
The label excerpts support treatment of opioid-induced constipation (OIC) but do not support the broader phrasing 'treat constipation that can occur when people use opioids' as a standalone generalization.
Methylnaltrexone is an opioid receptor antagonist that targets constipation side effects rather than pain control.
While mechanism section 12.1 describes peripherally-acting mu-opioid receptor antagonism decreasing constipating effects of opioids without impacting opioid-mediated analgesic effects on the CNS, the statement is not directly quoted or exactly matched to the label wording about 'targets constipation side effects rather than pain control.'
Methylnaltrexone is typically considered when constipation persists despite standard constipation measures and when opioid pain therapy continues.
No label excerpt provided includes criteria such as trying standard constipation measures first or decision-making rationale.
The dosing schedule for methylnaltrexone depends on the specific formulation and patient factors such as body weight and clinical status.
The label excerpts provided include weight-based dosing for renal/hepatic impairment (and differing regimens by indication), but the generalized statement about 'clinical status' and overall dependency is not directly supported in the provided dosing excerpts.
In 'Relistor 150,' the '150' indicates tablet strength.
The label excerpt shows tablets are available as 150 mg, but it does not explicitly state that the product name/labeling uses '150' to indicate tablet strength.
Methylnaltrexone common gastrointestinal side effects include diarrhea.
The label excerpt mentions 'Severe or persistent diarrhea' as a serious adverse reaction elsewhere, but does not state that diarrhea is 'common' as a general 'common GI side effect.' No frequency ('common') data is provided.
Methylnaltrexone common gastrointestinal side effects include abdominal pain.
The label excerpt provided addresses severe/persistent or worsening abdominal pain in the context of perforation monitoring, but does not support 'common' GI side effect frequency.
Methylnaltrexone common gastrointestinal side effects include nausea.
No nausea adverse reaction is provided in the supplied label excerpts.
Methylnaltrexone common gastrointestinal side effects include cramping.
No cramping adverse reaction is provided in the supplied label excerpts.
Contradictions
Important Omissions
No mention of the Warnings/Precautions specifics included in the provided label excerpt (e.g., gastrointestinal perforation monitoring and discontinuation criteria; opioid withdrawal warning content).
Importance:
Moderate
Safety Assessment
Potential Patient Risk:
Moderate
Several included claims about dosing criteria and 'common' adverse effects are not supported by the supplied label excerpts and could mislead about frequency/typicality; however, the core indication and contraindication claims are supported.
Regulatory Assessment
| On Label |
No |
| Off-label Discussion |
No |
| Promotes Unapproved Use |
No |
| Hallucination Risk |
Moderate |
Recommendation
Partially Aligned
Primary Issue
Multiple claims (frequency of adverse reactions, product-name interpretation, generalized dosing considerations, and mechanism phrasing) are not supported by the provided FDA label excerpts.
Suggested Improvement
Restrict claims to directly supported label text (e.g., exact indication wording, contraindication wording, and mechanism description as quoted). Avoid asserting 'common' frequencies or naming-convention interpretations unless explicitly stated in the provided label.