Last reviewed 2026-04-20 · How we verify

Narcan (NALOXONE)

Narcan (naloxone) is a small molecule opioid antagonist developed by ADAPT and currently owned by Adapt. It targets the mu-type opioid receptor to reverse the effects of opioid overdose and dependence. Narcan is FDA-approved for various indications, including opiate-induced respiratory depression, opioid dependence, and overdose. As an off-patent medication, it is available from multiple generic manufacturers. Key safety considerations include its short half-life and low bioavailability.

At a glance

Approved indications

• Severe Pain Management

Boxed warnings

• WARNING: SERIOUS AND LIFE-THREATENING RISKS FROM USE OF PENTAZOCINE AND NALOXONE TABLETS Addiction, Abuse, and Misuse Because the use of Pentazocine and Naloxone Tablets exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death, assess each patient's risk prior to prescribing and reassess all patients regularly for the development of these behaviors and conditions [ see <WARNINGS ]. Life-Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression may occur with use of Pentazocine and Naloxone Tablets, especially during initiation or following a dosage increase. To reduce the risk of respiratory depression, proper dosing and titration of Pentazocine and Naloxone Tablets are essential [ see <WARNINGS ]. Accidental Ingestion Accidental ingestion of even one dose of Pentazocine and Naloxone Tablets, especially by children, can result in a fatal overdose of Pentazocine Hydrochloride [ see <WARNINGS ]. Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of Pentazocine and Naloxone Tablets and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate [see Warnings , Precautions; Drug Interactions]. Neonatal Opioid Withdrawal Syndrome (NOWS) Advise pregnant women using opioids for an extended period of time of the risk of Neonatal Opioid Withdrawal Syndrome, which may be lifethreatening if not recognized and treated. Ensure that management by neonatology experts will be available at delivery [ see <WARNINGS ]. Opioid Analgesic Risk Evaluation and Mitigation Strategy (REMS) Healthcare providers are strongly encouraged to complete a REMS compliant education program and to counsel patients and caregivers on serious risks, safe use, and the importance of reading the Medication Guide with each prescription [ see <WARNINGS ].

Common side effects

• Cardiac arrest
• Death
• Coma
• Encephalopathy
• Pulmonary edema
• Ventricular fibrillation
• Ventricular tachycardia
• Convulsions
• Grand mal convulsion
• Paraesthesia
• Agitation
• Hallucination

Drug interactions

• benzodiazepines and other CNS depressants (including alcohol, sedative hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, and other opioids)
• serotonergic drugs (SSRIs, SNRIs, TCAs, triptans, 5-HT3 receptor antagonists, mirtazapine, trazodone, tramadol, cyclobenzaprine, metaxalone, MAO inhibitors)
• monoamine oxidase inhibitors (MAOIs)
• mixed agonist/antagonist and partial agonist opioid analgesics (butorphanol, nalbuphine, pentazocine, buprenorphine)
• muscle relaxants

Key clinical trials

• Examining Analgesic Synergy and Efficacy in Trauma Care (PHASE4)
• A Phase 2 Safety, Tolerability, PK, and Efficacy Study of CS-1103 Following Fentanyl Challenge With Naloxone Blockade (PHASE2)
• Integrated Outpatient Treatment of Opioid Use Disorder and Severe Injection Related Infections (PHASE2)
• Pharmacological and Behavioral Treatment After Bariatric Surgery: Acute (Stage 1) (PHASE2,PHASE3)
• Kentucky Women's Justice Community Overdose Innovation Network - Phase II (NA)
• Lemborexant Augmentation of Naltrexone for Alcohol Craving and Sleep (PHASE3)
• Machine-Learning Prediction and Reducing Overdoses With EHR Nudges (NA)
• A Multiple Health Behavior Change (MHBC) Intervention for Weight Loss and Smoking Cessation for Pre-Bariatric Surgery Patients (PHASE1,PHASE2)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Narcan CI brief — competitive landscape report
• Narcan updates RSS · CI watch RSS
• Adapt portfolio CI