09/03/2025
Nalmefene is unsafe for individuals w opioid dependency or certain severe medical conditions due to the risk of triggering severe opioid withdrawal and cardiovascular complications.
Patients should also exercise caution regarding respiratory depression to recur after nalmefene's effects.Individuals who should not use nalmefene do not use nalmefene if any of the following apply:
• You are currently dependent on opioids or have recently used them.
• Nalmefene is an opioid antagonist, meaning it blocks opioid receptors. In people with opioid dependence, this will trigger a sudden and severe withdrawal.
• You have a known hypersensitivity or allergy to nalmefene.
• You have severe hepatic (liver) or renal (kidney) impairment, as these organs are responsible for metabolizing and removing the drug from the body.
•Compromised function can increase the risk of toxicity.
• You are experiencing acute alcohol withdrawal syndrome, as nalmefene can worsen symptoms.
• You are pregnant or breastfeeding. Animal studies have shown potential adverse effects on fetal development, and the effects on breastfed infants are unknown.
• You are a child under 12 years of age. The safety and effectiveness of nalmefene have not been established in this age group.
📍Significant risks and side effects
Precipitated opioid withdrawal: In those with opioid dependence, nalmefene can cause a sudden, intense withdrawal syndrome.
Symptoms may include body aches, fever, sweating, diarrhea, stomach cramps, increased heart rate, and hypertension.
Recurrent respiratory depression: The effects of long-acting opioids can outlast the action of nalmefene. This causes respiratory depression to recur after initial treatment.
Patients must be monitored closely by emergency medical services after receiving nalmefene.
Cardiovascular issues: The abrupt reversal of opioid effects can stress the cardiovascular system. Rare but serious side effects include ventricular fibrillation, pulmonary edema, and cardiac arrest.
Patients with pre-existing heart conditions should use nalmefene with extreme caution.
Psychiatric disturbances: Anxiety, confusion, and hallucinations have been reported, especially in those with pre-existing mental health conditions.
Suicidal ideation has also been linked to nalmefene use in some reports.
Liver toxicity: Hepatic enzymes have been associated with nalmefene, particularly in those with underlying liver disease.
Misidentification of "Nolfi" for naloxone
The name "Nolfi" likely comes from a misinterpretation or misspelling of one of the brand names or alternatives to naloxone.
Nalmefene (Opvee): This is a newer nasal spray medication used to reverse opioid overdoses, like naloxone, but it has a longer duration of action. The "nal" and "fene" could be mistaken for a version of "Nolfi."
It can induce withdrawal symptoms ASAP!
This happens because naloxone displaces opioids from receptors in the brain. For someone who is physically dependent on op**tes / opioids, this can trigger a rapid onset of withdrawal, which can involve:
📍 Nausea and vomiting
📍 Body aches
📍 Irritability and agitation
It is not a substitute for emergency medical care. The effects of some opioids can outlast a dose of naloxone, breathing problems could return. It is crucial to call emergency services after administering naloxone.
**te 👃🏼
