Applies to nalmefene: injection solution.
Serious side effects of Nalmefene
Along with its needed effects, nalmefene 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 while taking nalmefene:
More common
- Burred 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
Other side effects of Nalmefene
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
- 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
For Healthcare Professionals
Applies to nalmefene: injectable solution.
Gastrointestinal
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
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]
Respiratory side effects have included pharyngitis (less than 1%). Pulmonary edema is an uncommon effect that has occurred with nalmefene administration.[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.
