This grade answers one narrow question: how strong is the public evidence and safety record behind this drug, and how clean is its money trail and court record? It is not a verdict on whether the drug is right for you.
Listed on the WHO Model List of Essential Medicines: a global expert panel judged it among the medicines a health system should always have, on evidence of value, not marketing.
INDICATIONS AND USAGE Naltrexone Hydrochloride Tablets, USP are indicated in the treatment of alcohol dependence and for the blockade of the effects of exogenously administered opioids. Naltrexone Hydrochloride Tablets, USP have not been shown to provide any therapeutic benefit except as part of an appropriate plan of management for the addictions.
CONTRAINDICATIONS Naltrexone hydrochloride is contraindicated in: Patients receiving opioid analgesics. Patients currently dependent on opioids, including those currently maintained on opiate agonists (e.g., methadone) or partial agonists (e.g., buprenorphine). Patients in acute opioid withdrawal (see WARNINGS ). Any individual who has failed the naloxone challenge test or who has a positive urine screen for opioids. Any individual with a history of sensitivity to naltrexone hydrochloride or any other components of this product. It is not known if there is any cross-sensitivity with naloxone or the phenanthrene containing opioids.
WARNINGS Vulnerability to Opioid Overdose After opioid detoxification, patients are likely to have reduced tolerance to opioids. As the blockade of exogenous opioids provided by naltrexone hydrochloride wanes and eventually dissipates completely, patients who have been treated with naltrexone hydrochloride may respond to lower doses of opioids than previously used, just as they would shortly after completing detoxification. This could result in potentially life-threatening opioid intoxication (respiratory compromise or arrest, circulatory collapse, etc.) if the patient uses previously tolerated doses of opioids. Cases of opioid overdose with fatal outcomes have been reported in patients after discontinuing treatment. Patients should be alerted that they may be more sensitive to opioids, even at lower doses, after naltrexone hydrochloride treatment is discontinued. It is important that patients inform family members, and the people closest to the patient of this increased sensitivity ot opioids and the risk of overdose (see PRECAUTIONS, Information for Patients ). There is also the possibility that a patient who is treated with naltrexone hydrochloride could overcome the opioid bloc...
ADVERSE REACTIONS During two randomized, double-blind placebo-controlled 12-week trials to evaluate the efficacy of naltrexone hydrochloride as an adjunctive treatment of alcohol dependence, most patients tolerated naltrexone hydrochloride well. In these studies, a total of 93 patients received naltrexone hydrochloride at a dose of 50 mg once daily. Five of these patients discontinued naltrexone hydrochloride because of nausea. No serious adverse events were reported during these two trials. While extensive clinical studies evaluating the use of naltrexone hydrochloride in detoxified, formerly opioid-dependent individuals failed to identify any single, serious untoward risk of naltrexone hydrochloride use, placebo-controlled studies employing up to five fold higher doses of naltrexone hydrochloride (up to 300 mg per day) than that recommended for use in opiate receptor blockade have shown that naltrexone hydrochloride causes hepatocellular injury in a substantial proportion of patients exposed at higher doses (see WARNINGS and PRECAUTIONS, Laboratory Tests ). Aside from this finding, and the risk of precipitated opioid withdrawal, available evidence does not incriminate naltrexone ...
Source: FDA SPL label for Naltrexone Hydrochloride (Elite Laboratories, Inc.), effective 20260521. Full label on DailyMed.
These are counts of reports people filed, not rates of harm. Anyone can file one, and nobody checks whether the drug was the cause. Millions of doses are taken for every report sent, so the useful part is how this drug compares with the average across all drugs.
| 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
|---|---|---|---|---|---|---|---|
| 3,488 | 3,888 | 2,914 | 2,736 | 2,127 | 1,657 | 1,637 | 897 |
8,944 reports blaming this drug for every million Medicare prescriptions filled, which is 3.2× the typical drug on this site. (4,168 reports in 2024–2026, against 466,006 Medicare fills in one year. This is the one number here that accounts for how many people take the drug.)
Source: the FDA's Adverse Event Reporting System (FAERS). Reports are voluntary and unverified. Drugs that are prescribed a lot, in the news, or in lawsuits attract more reports, so the percentages are compared with the whole database to correct for that partly, not fully.
| Date | Class | Firm | Reason |
|---|---|---|---|
| 04/2022 | Class II | Mckesson Medical-Surgical Inc. Corporate Office | cGMP deviations: Temperature abuse |
| 09/2019 | Class II | Alkermes, Inc. | Labeling: Not Elsewhere Classified. Drug product kit recalled due to 1 inch needles being placed in the 1 1/2 inch needle cardboard sleeve labelled as administration needles. The product vial is not impacted. |
| 08/2019 | Class II | Alkermes Inc | Labeling: Not Elsewhere Classified. Drug product kit recalled due to 1 inch needles being placed in the 1 1/2 inch needle cardboard sleeve labelled as administration needles. The product vial is not impacted. |
| 03/2014 | Class II | Alkermes, Inc. | Customer complaints for failure to deliver the dose. |
| 11/2012 | Class II | Alkermes, Inc. | Lack of Assurance of Sterility: Product did not meet the criteria for container closure integrity testing during routine 24 month stability testing. |
Class I = reasonable probability of serious harm. Class II = temporary or reversible harm. Class III = unlikely to harm. Most generic recalls are manufacturing or labeling defects for one lot, not a verdict on the molecule.
Counts measure how much evidence exists and how transparent it is, not how big the benefit is. For that, ask your prescriber: if 100 people like me took this, how many would get better because of it, and how many would be harmed? (Doctors call these the "number needed to treat" and "number needed to harm.") It differs by condition and is the number drug ads leave out. Sources: PubMed, ClinicalTrials.gov.
In 2024, drug companies reported $626,736 in payments to US physicians and hospitals tied to this drug across 9,491 transactions (Vivitrol $626,736).
No pending federal MDL names this drug or its brands.
Not named in any federal pharmaceutical settlement of $100M or more on record.
Sources: CMS Open Payments (Sunshine Act); Judicial Panel on Multidistrict Litigation pending docket list; DOJ settlements as tabulated on Wikipedia with links to the primary record. State-court and individual suits are not included.
Same ATC pharmacological class, graded ones first, best grade at the top. Being in the same class does not make them interchangeable for your condition; it makes them worth asking about.