Naltrexone

Drug information

Drug's link(s)

https://go.drugbank.com/drugs/DB00704

Generic name

Naltrexone

Brand names

VIVITROL

Compound type

Small molecule

Drug class/category

Not provided

Summary

Naltrexone long-acting injectable (LAI) is an opioid receptor antagonist with activity at μ, κ, and δ receptors, indicated for Alcohol Use Disorder and Opioid Use Disorder. VIVITROL® uses Medisorb® extended-release technology and is administered as a once-monthly intramuscular injection. An initial release occurs ~2 hours post-injection, followed by a secondary release at 2–3 days. Steady state is reached by ~14 days, with therapeutic plasma levels (>1–2 ng/mL) maintained for 28–31 days, providing continuous receptor antagonism across the dosing interval. Compared with oral naltrexone, long‑acting intramuscular naltrexone demonstrates a similar overall safety profile, while reducing risks associated with daily dosing non‑adherence.

Approval status

Naltrexone 380 mg long‑acting intramuscular injection is currently approved only in the United States under the brand name VIVITROL®. Although, the company submitted Marketing Authorisation Applications (MAA) for this product in the United Kingdom and Germany on 02 April 2007.

Regulatory authorities

VIVITROL® (naltrexone for extended‑release injectable suspension), 380 mg, received approval from the U.S. Food and Drug Administration on 13 April 2006.

Therapeutic area(s)

Substance use disorders

Use case(s)

Treatment

Administration route

Intramuscular

Associated long-acting platforms

Polymer-based particles

Use of drug

Ease of administration

Administered by a community health worker
Administered by a nurse
Administered by a specialty health worker

Frequency of administration

Monthly

User acceptance

Naltrexone Microspheres is contraindicated in:
 Patients receiving opioid analgesics
 Patients with current physiologic opioid dependence
 Patients in acute opioid withdrawal
 Any individual who has failed the naloxone challenge test or has a positive urine
screen for opioids
 Patients who have previously exhibited hypersensitivity to naltrexone, PLG,
carboxymethylcellulose, or any other components of the diluent.

Dosage

Available dose and strength

380 mg IM

Maximum dose

380 mg every 4 weeks

Recommended dosing regimen

The recommended dose of VIVITROL is 380 mg delivered intramuscularly (IM) as a gluteal injection, every 4 weeks or once a month, alternating buttocks for each subsequent injection, using the kit components provided in the package.

Additional comments

Prior to initiating VIVITROL, an opioid-free duration of a minimum of 7–10 days is recommended for patients, to avoid precipitation of opioid withdrawal that may be severe enough to require hospitalization

Dosage link(s)

https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/021897s052lbl.pdf#page=33

Associated compounds, formulations and regimens

Not provided

Associated technologies

Not provided

Additional information

Not provided

Developer(s)

Originator

Ireland

Alkermes

Alkermes plc is a Dublin-based biopharmaceutical company founded in 1987 that focuses on developing medicines for neuroscience. The company commercializes treatments for alcohol and opioid dependence (VIVITROL), schizophrenia (ARISTADA, ARISTADA INITIO), and bipolar I disorder (LYBALVI). Alkermes utilizes three primary proprietary technologies - LinkeRx, NanoCrystal, and Medisorb.

Drug structure

Scale-up and manufacturing prospects

Scale-up prospects

VIVITROL is manufactured exclusively at Alkermes' facility in Wilmington, Ohio.

Tentative equipment list for manufacturing

1. Static mixers (first and second inline mixers) 2. Positive‑displacement pumps 3. Stirred extraction vessels (primary & secondary extraction) 4. Custom vibratory sieves (25 µm & 150 µm) 5. Vacuum dryer with nitrogen bleed 6. Freezers (−20 °C) 7. Temperature‑controlled baths (5–10 °C and ambient)

Manufacturing

Manufacturing process of Medisorb Technology based Naltrexone includes: Slow crystallization, fast crystallization, extended‑release PLGA microparticles via solvent extraction, reslurry, static mixing, drying cycles. 1. Prepare polymer solution by dissolving 75:25 DL‑PLGA in ethyl acetate (EtAc) → 16.7% w/w. 2. Solvation / crystallization in different solvents. 3. Solvate formation (ethanol, benzyl alcohol, methanol, DMF, dichloromethane, etc.). 4. Hydrate formation from water. 5. Anhydrous forms from acetonitrile crystallization. 6. Amorphous form generated by melting at 180–190 °C and quenc

Specific analytical instrument required for characterization of formulation

XRPD (phase ID, crystallinity), Differential Scanning Calorimetry (DSC) (thermal behavior), Infrared ATR (IR‑ATR) (functional group identification) using MIRacle™ single‑reflection horizontal ATR (ZnSe)

Excipients & delivery device(s)

Proprietary excipients used

Not provided

Novel excipients or existing excipients at a concentration above Inactive Ingredient Database (IID) for the specified route of administration

1. Polylactide-co-glycolide (PLG) 2. Carboxymethylcellulose sodium salt 3. Polysorbate 20 4. Sodium chloride 5. Water for injection (WFI)

Residual solvents used

MeCl (methylene chloride), Heptane, Benzyl alcohol, Ethanol, and Ethyl acetate

Delivery device(s)

No delivery device

Safety, Efficacy and Evidence Summary

Safety

Not provided

Efficacy

Not provided

Evidence Summary

Not provided

References and relevant studies

Not provided

Naltrexone

Drug information

Therapeutic area(s)

Administration route

Associated long-acting platforms

Use of drug

Dosage

Associated compounds, formulations and regimens

Associated technologies

Additional information

Developer(s)

Alkermes

Drug structure

Scale-up and manufacturing prospects

Excipients & delivery device(s)

Safety, Efficacy and Evidence Summary

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