Description and Brand Names

Drug information provided by: Merative, Micromedex®

Descriptions


Nalmefene injection is used for emergency treatment of an opioid overdose or a possible overdose. It will temporarily reverse the effects of an opioid medicine. Some signs and symptoms of an opioid emergency are breathing problems (which can range from slow or shallow breathing to no breathing), extreme sleepiness, and low blood pressure.

This medicine is available only with your doctor's prescription.

This product is available in the following dosage forms:

  • Solution

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of nalmefene injection in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of nalmefene injection in the elderly. However, elderly patients are more likely to have age-related kidney, liver, or heart problems, which may require caution and an adjustment in the dose for patients receiving nalmefene injection.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Alfentanil
  • Anileridine
  • Benzhydrocodone
  • Buprenorphine
  • Butorphanol
  • Codeine
  • Dezocine
  • Diacetylmorphine
  • Difenoxin
  • Dihydrocodeine
  • Diphenoxylate
  • Ethylmorphine
  • Fentanyl
  • Hydrocodone
  • Hydromorphone
  • Ketobemidone
  • Levorphanol
  • Meperidine
  • Meptazinol
  • Methadone
  • Morphine
  • Morphine Sulfate Liposome
  • Nalbuphine
  • Nicomorphine
  • Opium
  • Opium Alkaloids
  • Oxycodone
  • Oxymorphone
  • Papaveretum
  • Paregoric
  • Pentazocine
  • Piritramide
  • Remifentanil
  • Sufentanil
  • Tapentadol
  • Tilidine
  • Tramadol

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Heart or blood vessel disease or
  • Kidney disease or
  • Liver disease—Use with caution. May make these conditions worse.

Proper Use

A nurse or other trained health professional will give you this medicine in a medical facility. It is given through a needle placed into one of your veins. It can also be given as a shot under your skin or into a muscle.

This medicine should be given immediately upon when a suspected or known overdose of an opioid has occurred. This will help prevent serious breathing problems that can lead to death.

Precautions

The effects of the opioid medicine may last longer than the effects of the nalmefene. This means the breathing problems could come back. Always call for emergency help after the first dose of nalmefene.

Severe opioid withdrawal symptoms may happen suddenly after receiving this medicine. These include fast heartbeat, death, and increased blood pressure.

This medicine may cause heart or blood vessel problems (eg, pulmonary edema, tachycardia, ventricular fibrillation, high or low blood pressure). Check with your doctor right away if you have blue lips and fingernails, chest pain, coughing that sometimes produces a pink frothy sputum, difficulty, fast, or noisy breathing, fast heartbeat, fainting, increased sweating, trouble breathing, swelling in the legs and ankles, or unusual tiredness or weakness.

Nalmefene injection may not be able to completely reverse the opioid effects (eg, respiratory depression) of buprenorphine.

Side Effects

Along with its needed effects, a medicine 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 or nurse immediately if any of the following side effects occur:

More common

  1. Burred vision
  2. dizziness
  3. fast, pounding, or irregular heartbeat or pulse
  4. headache
  5. nervousness
  6. pounding in the ears
  7. slow or fast heartbeat

Less common

  1. Confusion
  2. dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  3. feeling of warmth or heat
  4. flushing or redness of the skin, especially on the face and neck
  5. sweating
  6. unusual tiredness or weakness

Rare

  1. Anxiety
  2. chest pain or discomfort
  3. discouragement
  4. dry mouth
  5. feeling sad or empty
  6. hyperventilation
  7. irritability
  8. lack of appetite
  9. loss of interest or pleasure
  10. muscle twitching or jerking
  11. rhythmic movement of the muscles
  12. shaking
  13. trouble breathing
  14. trouble concentrating
  15. trouble sleeping

Incidence not known

  1. Blue lips or fingernails
  2. coughing that sometimes produces a pink frothy sputum
  3. difficulty, fast, or noisy breathing
  4. pale skin
  5. swelling in the legs and ankles

Some side effects 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

  1. Nausea
  2. vomiting

Less common

  1. Chills

Rare

  1. Body aches or pain
  2. cough
  3. decrease in frequency of urination
  4. decrease in urine volume
  5. difficulty in passing urine
  6. dryness or soreness of the throat
  7. fever
  8. itching skin
  9. painful urination
  10. stuffy or runny nose
  11. swollen glands in the neck
  12. trouble swallowing
  13. voice changes

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Portions of this document last updated: Feb. 01, 2024

Original article: https://www.mayoclinic.org/drugs-supplements/nalmefene-injection-route/description/drg-20541318