Nalmefene (Injection)

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.

The effects of the opioid medicine may last longer than the effects of the Nalmefene (Injection). This means that breathing problems could return. 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 (e.g., 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 (e.g., respiratory depression) of buprenorphine.

In deciding to use a medicine, you need to consider the risks of taking it against the benefits it may provide. This decision will be made between you and your doctor. For this medicine, consider the following:

Allergies

Inform your doctor if you have ever had any unusual or allergic reactions to this medicine or any other medications. Also, tell your healthcare professional about any other allergies you may have, such as to foods, dyes, preservatives, or animals. For non-prescription products, carefully read the label or package ingredients.

Pediatric

There haven't been appropriate studies to understand how nalmefene injection affects children. Safety and effectiveness have not been established.

Geriatric

Current studies have not shown specific issues for elderly patients that would limit the use of nalmefene injection in older adults. However, older patients are more likely to have kidney, liver, or heart problems related to aging, which may require caution and adjustments in the dose when using nalmefene injection.

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medicine while breastfeeding. Consider the potential benefits and risks before using this medication while breastfeeding.

Interactions with Medicines

Some medicines should not be taken together at all, while in other cases, two different medicines may be used together even if there is a chance of interaction. In these situations, your doctor may adjust the dose or take other precautions. It is especially important for your healthcare professional to know if you are taking any of the medicines listed below while receiving this medicine. The following interactions are significant and may not cover all possibilities.

Using this medicine with any of the following medicines is not recommended. Your doctor may choose not to prescribe this medication or change some of your other medications.

• 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

Interactions with Food/Tobacco/Alcohol

Some medicines should not be taken around the time of eating food or certain types of food due to potential interactions. Drinking alcohol or using tobacco with certain medicines may also cause interactions. Discuss with your healthcare professional about using your medicine with food, alcohol, or tobacco.

Other Medical Problems

Other medical issues may impact the use of this medicine. Make sure to inform your doctor if you have any other medical problems, especially:

• Heart or blood vessel disease or
• Kidney disease or
• Liver disease—Use with caution. It may worsen these conditions.

Along with its necessary effects, a medicine may cause some unwanted effects. Not all of these side effects may happen, but if they do, they may require medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

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

Less common

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

Rare

• Anxiety
• chest pain or discomfort
• discouragement
• dry mouth
• feeling sad or empty
• hyperventilation
• irritability
• lack of appetite
• loss of interest or pleasure
• muscle twitching or jerking
• rhythmic movement of the muscles
• shaking
• trouble breathing
• trouble concentrating
• trouble sleeping

Incidence not known

• Blue lips or fingernails
• coughing that sometimes produces a pink frothy sputum
• difficulty, fast, or noisy breathing
• pale skin
• 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

• Nausea
• vomiting

Less common

• Chills

Rare

• Body aches or pain
• cough
• decrease in frequency of urination
• decrease in urine volume
• difficulty in passing urine
• dryness or soreness of the throat
• fever
• itching skin
• painful urination
• stuffy or runny nose
• swollen glands in the neck
• trouble swallowing
• 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.

Available Dosage Forms:

• Solution

Therapeutic Class: Antidote

Pharmacologic Class: Nalmefene

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.

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