Naltrexone Side Effects
Applies to naltrexone: oral capsule, oral tablet.
Other dosage forms:
Common side effects of naltrexone
Some side effects of naltrexone 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 side effects
- abdominal or stomach cramping or pain (mild or moderate)
- anxiety, nervousness, restlessness or trouble sleeping
- headache
- joint or muscle pain
- nausea or vomiting
- unusual tiredness
Less common side effects
- chills
- constipation
- cough, hoarseness, runny or stuffy nose, sinus problems, sneezing, or sore throat
- diarrhea
- dizziness
- fast or pounding heartbeat
- increased thirst
- irritability
- loss of appetite
- sexual problems in males
Serious side effects of naltrexone
Along with its needed effects, naltrexone 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 immediately if any of the following side effects occur while taking naltrexone:
Less common side effects
- skin rash
Rare side effects
- abdominal or stomach pain (severe)
- blurred vision, aching, burning, or swollen eyes
- chest pain
- confusion
- discomfort while urinating or frequent urination
- fever
- hallucinations or seeing, hearing, or feeling things that are not there
- itching
- mental depression or other mood or mental changes
- ringing or buzzing in the ears
- shortness of breath
- swelling of the face, feet, or lower legs
- weight gain
For healthcare professionals
Applies to naltrexone: compounding powder, intramuscular powder for injection extended release, oral capsule, oral tablet.
Nervous system adverse events
- Very common (10% or more): Headache (25%), dizziness/syncope (13%)
- Common (1% to 10%): Somnolence/sedation
- Frequency not reported: Lethargy, cerebral arterial aneurysm, convulsions, disturbance in attention, dysgeusia, mental impairment, migraine, ischemic stroke, paresthesia[Ref]
Psychiatric
- Very common (10% or more): Insomnia/sleep disorder (14%), anxiety (12%)
- Common (1% to 10%): Depression
- Uncommon (0.1% to 1%): Suicide attempt/ideation
- Frequency not reported: Irritability, abnormal dreams, agitation, alcohol withdrawal syndrome, euphoric mood, delirium, libido decreased[Ref]
Gastrointestinal
- Very common (10% or more): Nausea (33%), vomiting NOS (14%), diarrhea (13%), abdominal pain (11%)
- Common (1% to 10%): Dry mouth, toothache
- Frequency not reported: Abdominal discomfort, colitis, constipation, flatulence, gastroesophageal reflux disease, gastrointestinal hemorrhage, hemorrhoids, pancreatitis acute, paralytic ileus[Ref]
Hepatic
- Very common (10% or more): Alanine aminotransferase increased (13%), aspartate aminotransferase increased (10%)
- Common (1% to 10%): Gamma-glutamyltransferase increased
- Frequency not reported: Lymphadenopathy including cervical adenitis, white blood cell count increased, cholecystitis acute, cholelithiasis[Ref]
Local
- Very common (10% or more): Injection site tenderness (45%), injection site induration (35%), injection site pain (17%), other injection site reaction (primarily nodules, swelling) (15%), injection site pruritus (10%)
- Common (1% to 10%): Injection site ecchymosis[Ref]
Musculoskeletal
- Very common (10% or more): Arthralgia/arthritis/joint stiffness (12%)
- Common (1% to 10%): Back pain/stiffness, muscle cramps
- Frequency not reported: Chills, joint stiffness, muscle spasms, myalgia, pain in limb[Ref]
Other
- Very common (10% or more): Asthenic conditions (23%)
- Frequency not reported: Chest pain, chest tightness, abortion missed[Ref]
Cardiovascular
- Frequency not reported: Angina pectoris, angina unstable, atrial fibrillation, cardiac failure congestive, coronary artery atherosclerosis, myocardial infarction, palpitations, deep vein thrombosis[Ref]
Respiratory
- Frequency not reported: Chronic obstructive pulmonary disease, dyspnea, pharyngolaryngeal pain, sinus congestion[Ref]
Dermatologic
- Common (1% to 10%): Rash
- Frequency not reported: Face edema, night sweats, pruritus, sweating increased[Ref]
Metabolic
- Very common (10% or more): Anorexia/appetite decreased NOS/appetite disorder NOS (14%)
- Frequency not reported: Weight decreased, weight increased, appetite increased, dehydration[Ref]
Renal
- Very common (10% or more): Abnormal creatinine phosphokinase levels (17%)[Ref]
Hematologic
- Frequency not reported: Eosinophil counts increased, decreased platelet count[Ref]
Ocular
- Frequency not reported: Conjunctivitis, vision blurred[Ref]
Hypersensitivity
- Frequency not reported: Hypersensitivity reaction (including angioneurotic edema and urticaria)
- Postmarketing reports: Anaphylaxis[Ref]
Immunologic
- Very common (10% or more): Pharyngitis (11%)
- Common (1% to 10%): Nasopharyngitis
- Frequency not reported: Seasonal allergies[Ref]
References
1. (2018) "Product Information. Vivitrol (naltrexone)." Alkermes, Inc
2. (2018) "Product Information. Naltrexone Hydrochloride (naltrexone)." Accord Biopharma Inc
Frequently asked questions
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Further information
Naltrexone side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.