nalmefene

Generic name: nalmefene [ NAL-me-feen ]
Brand name: Revex
Drug class: Antidotes

What is nalmefene?

Nalmefene reverses the effects of opioid (OH-pee-oid) medications, also called narcotics. Opioid effects include drowsiness, low blood pressure, and slowed breathing.

Nalmefene is used to treat a narcotic overdose or other situation in which opioid side effects may be harmful.

Nalmefene may also be used for purposes other than those listed in this medication guide.

What is the most important information I should know about nalmefene?

If possible, before you receive nalmefene, tell your doctor if you have liver or kidney disease, heart disease for which you take medication, or a history of narcotic (opioid) addition.

In an overdose situation, it may not be possible before you are treated with nalmefene to tell your caregivers about any health conditions you have or if you are pregnant or breast-feeding. However, make sure any doctor caring for your pregnancy or your baby knows that you have received nalmefene, and if you were treated for a narcotic overdose.

After treatment with nalmefene, you will be watched to make sure the medication has been effective and you no longer have any effects of the opioid overdose.

Tell your caregivers right away if you have any of these symptoms after receiving nalmefene: extreme drowsiness, weak or shallow breathing, chest pain or fluttering, or feeling like you might pass out. Some of these may be signs that you need to receive additional doses of nalmefene.

Less serious side effects may include nausea, vomiting, stomach pain, muscle or joint pain, chills, anxiety, or depression.

What should I discuss with my health care provider before receiving nalmefene?

If possible, before you receive nalmefene, tell your doctor if you are allergic to any drugs, or if you have:

• a history of addiction to narcotics;

• liver disease;

• kidney disease; or

• heart disease (especially if you take heart medications).

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. However opioid medications are not recommended for use during pregnancy.

Nalmefene may pass into breast milk and could harm a nursing baby. If possible, tell your caregivers if you are breast-feeding a baby.

In an overdose situation, it may not be possible before you are treated with nalmefene to tell your caregivers about any health conditions you have or if you are pregnant or breast-feeding. However, make sure any doctor caring for your pregnancy or your baby knows that you have received nalmefene, and if you were treated for a narcotic overdose.

How is nalmefene given?

Nalmefene is given as an injection through a needle placed into a vein or muscle. You will receive this injection in a hospital or emergency setting.

After treatment with nalmefene, you will be watched to make sure the medication has been effective and you no longer have any effects of the opioid.

What happens if I miss a dose?

This medication is given in an emergency situation by a healthcare professional, so you are not likely to miss a dose.

What happens if I overdose?

Since nalmefene is given as needed by a healthcare professional, it is unlikely that you will receive an overdose of this medication.

What should I avoid after being treated with nalmefene?

Follow your doctor's instructions about any restrictions on food, beverages, or activity after you receive nalmefene.

Nalmefene side effects

If you are addicted to narcotics or have been using an opioid medicine for a long time, you may have unpleasant withdrawal symptoms when you receive nalmefene to reverse the effects of a narcotic overdose.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Tell your caregivers right away if you have any of these symptoms, some of which may be signs that you need to receive additional doses of nalmefene:

• extreme drowsiness;

• weak or shallow breathing;

• chest pain or fluttering in your chest; or

• feeling like you might pass out.

Less serious side effects may include:

• nausea, vomiting, stomach pain;

• muscle or joint pain;

• chills; or

• feeling anxious or depressed.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

Nalmefene dosing information

Usual Adult Dose for Reversal of Opioid Sedation:

Initial dose: 0.25 mcg/kg intravenously once as an initial dose, followed by 0.25 mcg/kg incremental doses at 2 to 5 minute intervals until the desired degree of opioid reversal is obtained.
If no response after cumulative dose of 1 mcg/kg administered, additional doses are unlikely to provide an effect.

Usual Adult Dose for Opioid Overdose:

Initial dose: 0.5 mg/70 kg IV one time. May follow with 1 mg/70 kg IV administered 2 to 5 minutes after initial dose. If no response after 1.5 mg/70 kg administered, additional doses are unlikely to provide an effect.

If there is reasonable suspicion of opioid dependency, an initial challenge dose of 0.1 mg/70 kg IV should be administered. If, after 2 minutes, there is no withdrawal response the recommended dosing should be followed.

If IV access is unavailable, administer 1 mg subcutaneously or intramuscularly.

What other drugs will affect nalmefene?

There may be other drugs that can interact with nalmefene. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors.

Further information

• Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

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Copyright 1996-2023 Cerner Multum, Inc. Version: 1.02. Revision Date: 2008-12-13, 10:06:14 AM.