Opvee Side Effects

Generic name: nalmefene

Medically reviewed by Drugs.com. Last updated on Mar 14, 2025.

Note: This document provides detailed information about Opvee Side Effects associated with nalmefene. Some dosage forms listed on this page may not apply specifically to the brand name Opvee.

Applies to nalmefene: nasal spray.

Other dosage forms:

• injection solution

Serious side effects of Opvee

Along with its needed effects, nalmefene (the active ingredient contained in Opvee) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking nalmefene:

More common side effects

• blurred vision
• dizziness
• fast, pounding, or irregular heartbeat or pulse
• headache
• nervousness
• pounding in the ears

Less common side effects

• agitation
• anxiety
• confusion
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• increased sweating
• unusual tiredness or weakness

Rare side effects

• chest pain or discomfort
• decrease in frequency of urination
• decrease in urine volume
• difficulty in passing urine
• discouragement
• feeling sad or empty
• irritability
• lack of appetite
• lack of interest or pleasure
• lightheadedness, dizziness, or fainting
• muscle twitching or jerking
• nervousness
• painful urination
• rhythmic movement of muscles
• shakiness in the legs, arms, hands, or feet
• sleepiness or unusual drowsiness
• slow or irregular heartbeat
• trembling or shaking of the hands or feet
• trouble breathing
• trouble concentrating
• trouble sleeping

Incidence not known

• blue lips and fingernails
• blurred vision
• body aches
• coughing that sometimes produces a pink frothy sputum
• diarrhea
• excessive crying
• fever
• goosebumps
• headache
• increase in blood pressure
• increased or excessive unconscious or jerking movements
• nausea
• no blood pressure or pulse
• pale skin
• pounding in the ears
• restlessness
• runny nose
• seizures
• shivering
• sneezing
• stomach cramps
• stopping of the heart
• swelling in the legs and ankles
• unconsciousness
• vomiting
• yawning

Other side effects of Opvee

Some side effects of nalmefene may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

• feeling of warmth
• redness of the face, neck, arms and occasionally, upper chest

Less common side effects

• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• change in taste
• decreased appetite
• loss of taste
• stuffy nose
• throat and mouth pain
• throat irritation

Rare side effects

• dry mouth
• dryness or soreness of the throat
• hoarseness
• tender, swollen glands in the neck
• trouble in swallowing
• voice changes

For healthcare professionals

Applies to nalmefene: injectable solution, nasal spray.

Gastrointestinal adverse events

Gastrointestinal side effects have occurred commonly, with nausea and vomiting observed in 18% and 9%, respectively, of treated patients. Diarrhea and dry mouth have been reported in less than 1% of patients.^[Ref]

Cardiovascular

Cardiovascular adverse effects including tachycardia, hypertension, hypotension, vasodilation, bradycardia, and arrhythmia have been reported in 5% or fewer of treated patients.^[Ref]

Nervous system

Nervous system side effects including postoperative pain, dizziness, headache, fever, and chills have been reported in less than 5% of treated patients. Somnolence, depression, agitation, nervousness, tremor, confusion, and myoclonus have been reported in less than 1% of patients.^[Ref]

Nalmefene administration may precipitate acute and extended withdrawal symptoms in opioid-dependent patients.^[Ref]

Respiratory

Respiratory side effects have included pharyngitis (less than 1%). Pulmonary edema is an uncommon effect that has occurred with nalmefene (the active ingredient contained in Opvee) administration.^[Ref]

A 21-year-old male with no significant past medical history had decreased respirations following an exploratory laparotomy for presumed appendicitis. The patient developed acute pulmonary edema after receiving 75 mcg nalmefene in 25 mcg increments over 10 minutes. Clinical resolution of symptoms was prompt after supplemental oxygen and furosemide. It took 36 hours for the chest X-ray to improve.^[Ref]

Dermatologic

Dermatologic side effects have infrequently included pruritus (less than 1%).^[Ref]

Genitourinary

Genitourinary side effects have included rare reports of urinary retention (less than 1%).^[Ref]

Other

Other side effects including fever (3%) and chills (1%) have been reported.

Further information

Opvee side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer