RELISTOR vs REZENOPY

Independent side-by-side comparison.

Rated against independent regulatory sources·Last updated June 7, 2026·How we rate

Possible drug interaction. RELISTOR and REZENOPY are different prescription medicines. Combining or switching between them can cause interactions — talk to a pharmacist or prescriber before making changes. This page is not medical advice.

Attribute	RELISTOR	REZENOPY
Rating	New	New
Pharmacy pays	—	$4.41 /mL
Type	RX	RX
Active ingredient	METHYLNALTREXONE BROMIDE	NALOXONE HYDROCHLORIDE
Manufacturer	Salix	Scienture
Dosage forms	Injectable, Tablet	Spray/Inhaler
Drug class	Opioid Antagonist	Opioid Antagonist
Boxed warning	None	None
Half-life	—	30 to 81 minutes (mean 64 ± 12 minutes)
Treats	Constipation	Opioid-Related Disorders, Respiration Disorders, Septic Shock

relistor rezenopy

Rating

New

Pharmacy pays

—

$4.41 /mL

Type

Active ingredient

METHYLNALTREXONE BROMIDE

NALOXONE HYDROCHLORIDE

Manufacturer

Salix

Scienture

Dosage forms

Injectable, Tablet

Spray/Inhaler

Drug class

Opioid Antagonist

Boxed warning

None

Half-life

—

30 to 81 minutes (mean 64 ± 12 minutes)

Treats

Constipation

Opioid-Related Disorders, Respiration Disorders, Septic Shock

Frequently asked questions

What is the difference between Relistor and Rezenopy?

Relistor contains Methylnaltrexone Bromide, while Rezenopy contains Naloxone Hydrochloride — they have different active ingredients.

Ratings are based on FDA regulatory (recall-safety) data. This comparison is for general reference only — not medical advice. Always consult a licensed professional before choosing or switching a medication.