The Shifting Landscape of Opioid Use Disorder Treatment
Opioid use disorder (OUD) is a chronic condition that requires sustained treatment, often involving a combination of medication, counseling, and behavioral therapy. Traditional medication options for OUD, such as daily oral methadone or buprenorphine, presented challenges with adherence and the potential for misuse. The development of long-acting injectable (LAI) medications represents a significant advancement in providing more flexible and effective treatment options. These LAIs, including buprenorphine products like Sublocade and Brixadi, deliver a stable, continuous dose, reducing the need for daily medication and allowing patients to focus more on their recovery.
Key Injectable Treatments for Opioid Dependence
Several injectable medications are available to treat opioid dependence, each with different properties and administration requirements.
Sublocade (Buprenorphine Extended-Release Injection)
Sublocade, the first once-monthly buprenorphine injection, is administered subcutaneously by a healthcare provider. In February 2025, the FDA approved a rapid initiation protocol and additional injection sites. This new protocol allows for Sublocade initiation after a single dose of transmucosal buprenorphine with a one-hour observation, eliminating the prior seven-day oral stabilization requirement.
Brixadi (Buprenorphine Extended-Release Injection)
Approved in May 2023, Brixadi offers both once-weekly and once-monthly buprenorphine injection options. Administered subcutaneously by a healthcare provider, Brixadi provides continuous buprenorphine release over its dosing period. Its flexible scheduling allows for personalized treatment plans.
Vivitrol (Extended-Release Naltrexone Injection)
Vivitrol is a once-monthly intramuscular injection containing naltrexone, an opioid antagonist. Unlike buprenorphine, Vivitrol blocks opioid receptors completely, preventing the euphoric effects of other opioids. Patients must be opioid-free for 7 to 10 days before starting Vivitrol to avoid precipitated withdrawal.
How Do Long-Acting Injectables Work?
Subcutaneous buprenorphine injections like Brixadi and Sublocade form a depot under the skin that releases buprenorphine steadily over a week or month. Buprenorphine is a partial opioid agonist that binds to opioid receptors, producing a weaker effect than full opioids. This action helps to:
- Reduce cravings: Stabilizes receptor activity, minimizing intense cravings.
- Prevent withdrawal symptoms: Effectively manages withdrawal without causing a high.
- Block other opioids: High doses can prevent other opioids from binding and producing effects.
Benefits of Injectable Options
LAIs offer significant advantages over daily oral medication, improving treatment outcomes.
- Enhanced Adherence: Eliminates daily dosing, improving treatment retention.
- Reduced Diversion and Misuse: Administered in a clinical setting, preventing illegal sale or misuse.
- Stable Medication Levels: Provides consistent drug levels, avoiding peaks and troughs.
- Increased Privacy and Flexibility: Fewer visits and no need to carry medication reduce stigma.
- Improved Outcomes: Shown to reduce illicit opioid use and improve well-being.
Comparison of Injectable OUD Medications
| Feature | Brixadi (Buprenorphine) | Sublocade (Buprenorphine) | Vivitrol (Naltrexone) |
|---|---|---|---|
| Drug Type | Partial Opioid Agonist | Partial Opioid Agonist | Opioid Antagonist |
| Dosing Schedule | Once-weekly or once-monthly | Once-monthly | Once-monthly |
| Administration | Subcutaneous (under the skin) injection by healthcare provider | Subcutaneous (under the skin) injection by healthcare provider | Intramuscular (in the muscle) injection by healthcare provider |
| Prior Detox Required? | No; can be started after a single transmucosal buprenorphine dose | No; rapid initiation protocol allows for single transmucosal dose prior to injection | Yes; must be opioid-free for 7-10 days |
| How it Works | Binds to opioid receptors to reduce cravings and withdrawal symptoms, with a ceiling effect | Binds to opioid receptors to reduce cravings and withdrawal symptoms, with a ceiling effect | Blocks opioid receptors completely, preventing effects of other opioids |
| Risk of Withdrawal | Low risk of precipitated withdrawal if started correctly after a period of stabilization on oral buprenorphine | Low risk of precipitated withdrawal if started correctly; rapid initiation protocol reduces risk for eligible patients | High risk of precipitated withdrawal if opioids are not fully cleared from the system |
Risks, Side Effects, and Restricted Access
Injectable OUD treatments carry potential risks and side effects. Common side effects of buprenorphine injections include injection site reactions, headache, and gastrointestinal issues. Intravenous self-injection is dangerous and can be fatal. These medications are available only through a restricted REMS program, requiring administration by a certified healthcare provider. Buprenorphine can also cause respiratory depression, especially when combined with CNS depressants. Healthcare providers must carefully assess patient health and concurrent medications.
Conclusion: A Promising Path Forward
Injectable buprenorphine and naltrexone represent significant advancements in OUD treatment. Brixadi offers flexible dosing and Sublocade's rapid initiation protocol improves access and options. These LAIs address adherence and diversion risks, supporting patients in their recovery as part of a comprehensive plan including counseling. Consult a healthcare professional for the best treatment path. More information is available on the {Link: SAMHSA website https://www.samhsa.gov/medications-substance-use-disorders/treatment-medications-counseling}.
