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Vivitrol Side Effects

Generic name: naltrexone

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jul 24, 2022.

Note: This document contains side effect information about naltrexone. Some dosage forms listed on this page may not apply to the brand name Vivitrol.


Common side effects of Vivitrol include: streptococcal pharyngitis, syncope, anxiety, arthralgia, arthritis, dizziness, drowsiness, fatigue, frequent headaches, headache, joint stiffness, nasopharyngitis, nausea, nervousness, obsessive compulsive disorder, panic attack, pharyngitis, posttraumatic stress disorder, sedated state, sinus headache, vomiting, induration at injection site, malaise, pain at injection site, and tenderness at injection site. Other side effects include: muscle cramps, muscle rigidity, muscle spasm, stiffness, depression, and twitching. Continue reading for a comprehensive list of adverse effects.

Applies to naltrexone: intramuscular powder for suspension extended release.

Serious side effects of Vivitrol

Along with its needed effects, naltrexone (the active ingredient contained in Vivitrol) 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 naltrexone:

More common

  • Bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  • body aches or pain
  • chills
  • congestion
  • cough
  • discouragement
  • dryness or soreness of the throat
  • ear congestion
  • fear
  • feeling sad or empty
  • fever
  • headache
  • hoarseness
  • irritability
  • lack of appetite
  • loss of interest or pleasure
  • loss of voice
  • nervousness
  • rash
  • runny or stuffy nose
  • sneezing
  • sore throat
  • tender, swollen glands in the neck
  • trouble breathing
  • trouble concentrating
  • trouble sleeping
  • trouble swallowing
  • unusual tiredness or weakness
  • voice changes

Incidence not known

  • Arm, back, or jaw pain
  • black, tarry stools
  • bladder pain
  • bloating
  • bloody or cloudy urine
  • bloody stools
  • blurred vision
  • chest pain, discomfort, tightness, or heaviness
  • chills
  • confusion
  • constipation
  • cough
  • cough producing mucus
  • decreased urination
  • diarrhea
  • difficult, burning, or painful urination
  • dilated neck veins
  • dizziness or lightheadedness
  • dry mouth
  • fainting
  • false or unusual sense of well-being
  • fast, irregular, pounding, or racing heartbeat or pulse
  • frequent urge to urinate
  • general feeling of discomfort or illness
  • hallucinations or seeing, hearing, or feeling things that are not there
  • headache, severe and throbbing
  • holding false beliefs that cannot be changed by fact
  • hyperventilation
  • increase in heart rate
  • increase in white blood cells
  • indigestion
  • irregular or rapid breathing
  • irritability
  • itching, pain, redness, swelling, tenderness, or warmth on the skin
  • joint or muscle pain
  • lower back or side pain
  • nausea
  • nervousness
  • numbness or tingling of the face, hands, or feet
  • pain or discomfort in the arms, jaw, back, or neck
  • pain, redness, or swelling in the arm or leg
  • pounding in the ears
  • redness and soreness of the eyes
  • restlessness
  • seizures
  • shaking
  • shivering
  • skin rash
  • slow or fast heartbeat
  • sores in the mouth
  • stomach cramps or pain
  • sunken eyes
  • sweating
  • swelling of the face, fingers, feet, or lower legs
  • swollen, painful, or tender lymph glands in the neck, armpit, or groin
  • thirst
  • tooth or gum pain
  • unusual excitement, nervousness, or restlessness
  • vomiting
  • vomiting of blood or material that looks like coffee grounds
  • watery or bloody diarrhea
  • weight gain
  • wrinkled skin

Get emergency help immediately if any of the following symptoms of overdose occur while taking naltrexone:

Symptoms of overdose

  • Sleepiness or unusual drowsiness

Other side effects of Vivitrol

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

  • Difficulty with moving
  • muscle stiffness
  • swelling or redness in the joints

Incidence not known

  • Bleeding after defecation
  • bloated or full feeling
  • change in taste
  • decreased interest in sexual intercourse
  • drowsiness
  • excess air or gas in the stomach or intestines
  • feeling of warmth
  • feeling unusually cold
  • heartburn
  • inability to have or keep an erection
  • increased sweating
  • loss in sexual ability, desire, drive, or performance
  • loss of taste
  • night sweats
  • passing gas
  • redness of the face, neck, arms, and occasionally, upper chest
  • relaxed and calm
  • sleepiness
  • sudden sweating
  • uncomfortable swelling around anus
  • unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
  • weight loss

For Healthcare Professionals

Applies to naltrexone: compounding powder, intramuscular powder for injection extended release, oral tablet.

Nervous system

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]


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]


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]


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]


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]


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]


Very common (10% or more): Asthenic conditions (23%)

Frequency not reported: Chest pain, chest tightness, abortion missed[Ref]


Frequency not reported: Angina pectoris, angina unstable, atrial fibrillation, cardiac failure congestive, coronary artery atherosclerosis, myocardial infarction, palpitations, deep vein thrombosis[Ref]


Frequency not reported: Chronic obstructive pulmonary disease, dyspnea, pharyngolaryngeal pain, sinus congestion[Ref]


Common (1% to 10%): Rash

Frequency not reported: Face edema, night sweats, pruritus, sweating increased[Ref]


Very common (10% or more): Anorexia/appetite decreased NOS/appetite disorder NOS (14%)

Frequency not reported: Weight decreased, weight increased, appetite increased, dehydration[Ref]


Very common (10% or more): Abnormal creatinine phosphokinase levels (17%)[Ref]


Frequency not reported: Eosinophil counts increased, decreased platelet count[Ref]


Frequency not reported: Conjunctivitis, vision blurred[Ref]


Frequency not reported: Hypersensitivity reaction (including angioneurotic edema and urticaria)

Postmarketing reports: Anaphylaxis[Ref]


Very common (10% or more): Pharyngitis (11%)

Common (1% to 10%): Nasopharyngitis

Frequency not reported: Seasonal allergies[Ref]

Frequently asked questions


1. "Product Information. Vivitrol (naltrexone)." Alkermes, Inc (2018):

2. "Product Information. Naltrexone Hydrochloride (naltrexone)." Accord Biopharma Inc (2018):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.