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opvee

Opvee (Nalmefene Hydrochloride) is an opioid antagonist used to treat Opioid-Related Disorders, Respiration Disorders, Drug Overdose.

Nalmefene Hydrochloride · by Indivior

Not yet rated· sourced from the FDA label
Rated against independent regulatory sources·Last updated June 7, 2026·How we rate
Verified againstopenFDANIH DailyMedRxClass

Key facts

Active ingredient
Nalmefene Hydrochloride
Form
Spray/Inhaler
Strength
Nalmefene Hydrochloride EQ 2.7MG BASE/SPRAY
Type
Prescription (Rx)
Brand or generic
Brand-name
Manufacturer
Indivior
FDA application
NDA217470

What is Opvee?

From the FDA label:OPVEE (nalmefene) nasal spray is a pre-filled, unit-dose intranasal spray. Nalmefene, an opioid antagonist, is a 6-methylene analogue of naltrexone. The molecular structure of nalmefene is presented below: Molecular Formula: C 21 H 25 NO 3 ∙HCl Molecular Weight: 375.9, CAS # 58895-64-0 Chemical Name: 17-(Cyclopropylmethyl)-4,5α-epoxy-6-methylenemorphinan-3,14-diol, hydrochloride salt. Nalmefene is a white to off-white crystalline powder which is freely soluble in methanol and water, with a pK of 7.63. Each OPVEE nasal spray unit delivers 2.7 mg nalmefene (equivalent to 3mg nalmefene hydrochloride) in 0.1 mL solution. Inactive ingredients include benzalkonium chloride, disodium ethylenediaminetetraacetate, dodecylmaltoside, sodium chloride, and purified water. The pH range is 4.1 to 4.9. Chemical Structure

How to use

OPVEE nasal spray is for intranasal use only ( 2.1 ) Seek emergency care immediately after use ( 2.1 ) Administer a single spray of OPVEE nasal spray intranasally into nose. ( 2.2 ) Administer additional doses of OPVEE nasal spray, using a new nasal spray with each dose, if the patient does not respond or responds and then relapses into respiratory depression, additional doses of OPVEE nasal spray may be given every 2 to 5 minutes until emergency medical assistance arrives. ( 2.2 ) Additional supportive and/or resuscitative measures may be helpful while awaiting emergency medical assistance. ( 2.2 ) 2.1 Important Administration Instructions OPVEE is for intranasal use only. The device is ready to use. No device assembly is required. Do not prime or test prior to administration. OPVEE nasal spray delivers its entire contents automatically, upon activation. Do not attempt to reuse OPVEE. Each unit-dose device contains a single dose of nalmefene and cannot be reused. No device assembly is required. Because treatment of suspected opioid overdose must be performed by someone other than the patient, instruct the prescription recipient to inform those around them about the presence of OPVEE nasal spray and the Instructions for Use . Instruct the patient or caregiver to read the Instructions for Use at the time they receive a prescription for OPVEE nasal spray. Emphasize the following…

Side effects

The following serious adverse reactions are discussed elsewhere in the labeling: Recurrent Respiratory and Central Nervous System Depression [see Warnings and Precautions (5.1) ] Precipitation of Severe Opioid Withdrawal [see Warnings and Precautions (5.3) ] Most common adverse reactions (incidence at least 2%) are nasal discomfort, headache, nausea, dizziness, hot flush, vomiting, anxiety, fatigue, nasal congestion, throat irritation, rhinalgia, decreased appetite, dysgeusia, erythema, and hyperhidrosis. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Indivior Inc. at 1-877-782-6966 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to the rates in clinical trials of another drug and may not reflect the rates observed in practice. The safety of OPVEE nasal spray is supported by safety and pharmacokinetic studies of OPVEE nasal spray in healthy subjects in a normal state and under steady state opioid agonism. The following adverse reactions were observed. In a pharmacokinetic study of 66 healthy adult volunteers exposed to one spray of OPVEE nasal spray in one nostril the most common adverse reactions were: nasal discomfort and dizziness. In a second pharmacokinetic study of 24…

Warnings

Important safety information

Risk of Recurrent Respiratory and Central Nervous System Depression : While the duration of action of nalmefene is as long as most opioids, a recurrence of respiratory depression is possible, therefore, keep patient under continued surveillance and administer repeat doses of OPVEE using a new nasal spray with each dose, as necessary, while awaiting emergency medical assistance ( 5.1 ) Limited Efficacy with Partial Agonists or Mixed Agonist/Antagonists : Reversal of respiratory depression caused by partial agonists or mixed agonists/antagonists, such as buprenorphine and pentazocine, may be incomplete. Larger or repeat doses may be required. ( 5.2 ) Precipitation of Severe Opioid Withdrawal : Use in patients who are opioid dependent may precipitate opioid withdrawal. In neonates, opioid withdrawal may be life-threatening if not recognized and properly treated. Monitor for the development of opioid withdrawal. ( 5.3 ) Risk of Cardiovascular (CV) Effects : Abrupt postoperative reversal of opioid depression may result in adverse CV effects. These events have primarily occurred in patients who had preexisting CV disorders or received other drugs that may have similar adverse CV effects. Monitor these patients closely in an appropriate healthcare setting after use of nalmefene hydrochloride. ( 5.3 ) Risk of Opioid Overdose from Attempts to Overcome the Blockade : Attempts to overcome opioid withdrawal symptoms caused by opioid antagonists with high or repeated doses of exogenous opioids may lead to opioid intoxication and death ( 5.4 ) 5.1 Risk of Recurrent Respiratory and Central Nervous System Depression Respiratory depression in the community overdose setting may be complex and involve the effects of multiple or unknown drugs, some of which may be long-acting opioids. While the duration of action of nalmefene is as long as most opioids, a recurrence of respiratory depression is possible, even after an apparently adequate initial response to OPVEE nasal spray treatment [See Clinical Pharmacology, Pharmacodynamics (12.3) ] . Therefore, it is necessary to seek emergency medical assistance immediately after administration of the first dose of OPVEE nasal spray and to keep the patient under continued surveillance. A second dose may be necessary if there is recurrence of symptoms of opioid overdose. Additional supportive and/or resuscitative measures may be helpful while awaiting emergency medical assistance [see Dosage and Administration (2.2) ]. 5.2 Risk of Limited Efficacy with Partial Agonists or Mixed Agonist/Antagonists Reversal of respiratory depression by partial agonists or mixed agonist/antagonists such as buprenorphine and pentazocine, may be incomplete. Repeat doses of OPVEE nasal spray may be required to antagonize buprenorphine because the latter has a long duration of action due to its slow rate of binding and subsequent slow dissociation from the opioid receptor [see Dosage and Administration (2.3) ] . Buprenorphine antagonism is characterized by a gradual onset of the reversal effects and a decreased duration of action of the normally prolonged respiratory depression. 5.3 Precipitation of Severe Opioid Withdrawal The use of OPVEE in patients who are opioid dependent may precipitate opioid withdrawal characterized by the following signs and symptoms: body aches, diarrhea, tachycardia, fever, runny nose, sneezing, piloerection, sweating, yawning, nausea or vomiting, nervousness, restlessness or irritability, shivering or trembling, abdominal cramps, weakness, and increased blood pressure. Abrupt postoperative reversal of opioid depression after using OPVEE may result in nausea, vomiting, sweating, tremulousness, tachycardia, hypotension, hypertension, seizures, ventricular tachycardia and fibrillation, pulmonary edema, and cardiac arrest. Death, coma, and encephalopathy have been reported as sequelae of these events. These events have primarily occurred in patients who had pre-existing cardiovascular disorders or received other drugs that may have similar adverse cardiovascular effects. After use of OPVEE, monitor patients with pre-existing cardiac disease or patients who have received medications with potential adverse cardiovascular effects for hypotension, ventricular tachycardia or fibrillation, and pulmonary edema in an appropriate healthcare setting. It has been suggested that the pathogenesis of pulmonary edema associated with the use of nalmefene is similar to neurogenic pulmonary edema, i.e., a centrally mediated massive catecholamine response leading to a dramatic shift of blood volume into the pulmonary vascular bed resulting in increased hydrostatic pressures. OPVEE is not indicated for use in patients less than 12 years of age. In neonates, opioid withdrawal may be life-threatening if not recognized and properly treated and may include the following signs and symptoms: convulsions, excessive crying, and hyperactive reflexes. Monitor the patient for the development of the signs and symptoms of opioid withdrawal. There may be clinical settings, particularly the postpartum period in neonates with known or suspected exposure to maternal opioid use, where it is preferable to avoid the abrupt precipitation of opioid withdrawal symptoms. In these settings, use an alternative, opioid antagonist product that can be titrated to effect and, where applicable, dosed according to weight. [see Use in Specific Populations (8.4) ] . 5.4 Risk of Opioid Overdose from Attempts to Overcome the Blockade OPVEE is unlikely to produce acute withdrawal symptoms in non-opioid dependent patients. The use of OPVEE nasal spray in patients who are opioid dependent may precipitate opioid withdrawal. Attempting to overcome opioid withdrawal symptoms caused by opioid antagonists with high or repeated doses of exogenous opioids could lead to opioid intoxication and death. Inform patients of the potential consequences of trying to overcome the opioid blockade. Get emergency medical assistance as soon as possible after use of OPVEE nasal spray regardless of withdrawal symptoms.

Who should not take Opvee

OPVEE nasal spray is contraindicated in patients known to be hypersensitive to nalmefene or to any of the other ingredients. Hypersensitivity to nalmefene or to any of the other ingredients. ( 4 )

Drug class

How this class works, per Opioid Antagonists - StatPearls - NCBI Bookshelf.

May treat (source: NIH RxClass)

See how Opvee ranks — best-rated opioid antagonist for:

Dosage forms

Spray/Inhaler

The forms currently marketed in the U.S., per the FDA National Drug Code Directory.

Ways to save

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Frequently asked questions

What does Opvee treat?
Opvee (Nalmefene Hydrochloride) may be used to treat opioid-related disorders, respiration disorders, drug overdose, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
How does Opvee work?
Opvee is a opioid antagonist. Opioid antagonists attach to the same brain and body receptors that opioids use, but without switching them on. By occupying those receptors, they block opioids from binding and can rapidly reverse an overdose or curb opioid cravings.
Is there a coupon or discount for Opvee?
pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Opvee. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
Who makes Opvee?
Opvee is marketed by Indivior. You can see Indivior's full profile, rating, and other products on pharmaranks.
Is Opvee a brand-name or generic drug?
Opvee is a brand-name product with the active ingredient Nalmefene Hydrochloride.
Is Opvee available over the counter?
No. Opvee is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
What forms does Opvee come in?
Opvee is currently marketed as spray/inhaler, per the FDA's National Drug Code Directory.
What class of drug is Opvee?
Opvee is classified as opioid antagonist, per the FDA's Established Pharmacologic Class.
Is Opvee FDA-registered?
Opvee is on record with the U.S. FDA under application number NDA217470. You can verify this on its official FDA label.
Is Opvee safe?
There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Opvee. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
What are the side effects of Opvee?
Opvee's side effects are taken directly from its FDA label. From the label: The following serious adverse reactions are discussed elsewhere in the labeling: Recurrent Respiratory and Central Nervous System Depression [see Warnings and Precautions (5.1) ] Precipitation of Severe Opioid Withdrawal [see Warnings and Precautions (5.3) ] Most common adverse reactions (incidence… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.

Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.

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