Generic name: Extended-release naltrexone

EXOPIO is developed by embedding naltrexone (NTX) in microspheres composed of a biodegradable copolymer, poly(d,l-lactide-co-glycolide) (PLGA), resulting in release of the active ingredient over a predetermined period. Upon injection, the microspheres begin to absorb water almost immediately, leading to a swelling of the microspheres. This process begins an initial release of the drug. As water absorption continues, the polymer begins to undergo hydrolysis. Later, physical erosion of the polymer occurs. The drug diffuses into the surrounding media as the polymer continues to undergo hydrolysis and erosion, resulting in a sustained release of the drug from the microspheres.
EXOPIO can maintain stable and pharmacologically relevant plasma concentrations of NTX for at least 30 days which leads to reduced administration frequency and improved patient compliance.
Mechanism of action
Naltrexone is a full opioid antagonist with highest affinity for the µ opioid receptors and little and no opioid activity.


Exopio is indicated for:
• Prevention of relapse to opioid dependence, following opioid detoxification

• Treatment of alcohol use disorder

Dosage form and strength
An injectable suspension containing 380 mg of naltrexone in a microsphere formulation in a single-dose vial
Supplied in a single-use kit containing:
• One vial 380 mg of Exopio microspheres
• One vial of diluent
• One 5-ml syringe
• One needle (pink color) for preparation
• Two needles (yellow color) for administration

Intramuscularly (IM) as a gluteal injection, once- monthly