Naltrexone Side Effects: How Long Nausea, Insomnia, Etc. Last

Last Updated: June 24, 2020

Authored by Olivier George, Ph.D.

Reviewed by Michael Espelin APRN

Naltrexone can help many addicts live better lives, but Vivitrol side effects can make treatment difficult. From naltrexone nausea to more serious concerns, such as liver damage, users need to know the possible symptoms they could end up dealing with. Here are the key facts about naltrexone side effects.

Naltrexone Implant Side Effects

Like any medication, naltrexone comes with certain related symptoms. Naltrexone side effects vary from person to person and between the different forms the medication takes. Vivitrol side effects tend to be most pronounced in the implant and injection versions of the drug. This is because when compared to the pill versions, the medication from the implant and injection will remain in the body longer.
Vivitrol shot side effects range from the common and annoying to the dangerous and rare. Patients need to be careful not to mistake withdrawal for naltrexone implant or injection side effects. Because naltrexone does not help with withdrawal symptoms, users can expect to experience them still unless they go through the proper rehabilitation treatment.

Common Side Effects

Common Vivitrol injection and implant side effects, seen in more than 10 percent of patients, include:

  • sleep disturbances
  • anxiety
  • nervousness
  • abdominal cramps and pains
  • nausea
  • vomiting
  • low energy levels
  • muscle pain
  • headache

naltrexone headache

Additionally, there are side effects of Vivitrol that are seen frequently with the shot. These side effects include:

  • pain at the injection site
  • swelling around the injection site
  • hardening of the skin where the injection was administered
  • bruising
  • redness

Uncommon Side Effects

Uncommon symptoms occur in less than 10 percent of patients. In general, these are considered to be bad Vivitrol side effects as they usually are more severe, though that is not uniformly the case.

Uncommon naltrexone effects include:

  • appetite loss
  • diarrhea
  • constipation
  • increased thirst
  • increased energy
  • depression
  • irritability
  • dizziness
  • skin rash
  • delayed ejaculation
  • decreased potency
  • chills
  • extreme fatigue
  • dark urine
  • yellowing of the skin or eyes
  • bruising or bleeding not associated with the injection or implant site

Rare Side Effects

Rare Vivitrol effects are seen in one percent or less of patients. However, some of these symptoms can be very dangerous and concerning.

Some rare side effects of naltrexone are:

  • nasal congestion
  • nasal itching
  • rhinorrhea
  • sneezing
  • sore throat
  • excess mucus
  • sinus troubles
  • heavy breathing
  • hoarseness
  • cough
  • shortness of breath
  • nose bleeds
  • phlebitis
  • edema
  • increased blood pressure
  • ECG changes
  • palpitations
  • tachycardia
  • excessive gas
  • hemorrhoids
  • ulcers
  • pain in the shoulders, legs, and knees
  • muscle tremors and twitching
  • urination pain or difficulties
  • decreased sex drive
  • oily skin
  • pruritus
  • acne
  • athlete’s foot
  • cold sores
  • alopecia
  • extreme depression
  • paranoia
  • restlessness
  • confusion
  • disorientation
  • hallucinations
  • nightmares
  • blurred vision
  • light sensitivity in the eyes
  • eye pain
  • clogged feeling in the ears
  • earaches
  • tinnitus
  • increased appetite
  • weight loss
  • weight gain
  • yawning
  • somnolence
  • fever
  • dry mouth
  • pounding headaches
  • inguinal pain
  • swollen glands
  • cold feet
  • hot spells

Low Dose Naltrexone Side Effects

Low dose Vivitrol is manufactured in the form of the pills rather than injections or implants. This is because other methods do not allow for smaller doses. In general, this therapy is used to treat conditions other than addiction, such as pain disorders.

Low dose naltrexone side effects have some overlap with those of injections and implants. For example, low dose naltrexone insomnia is quite common. Other potential symptoms of this type of therapy include:

  • general sleep disturbances, including vivid dreams
  • headaches
  • nausea
  • stiffness
  • spasms

It is also possible that something that may seem like a side effect of the medicine is the result of other medications or the condition being treated. Low dose naltrexone anxiety may actually be driven by the overall health of the user. Low dose naltrexone constipation could be due to a poor diet. To determine what is causing the issue, users should work closely with their prescribing doctor.

Naltrexone Side Effects During Pregnancy

Women who are currently undergoing Vivitrol therapy may wish to continue use while pregnant. This is especially true for those women who are using it to get through day to day life, such as naltrexone for pain treatment. There are also women who may be active addicts who find themselves pregnant and wish to start therapy with the drug. But the question is if Vivitrol and pregnancy are a good mix.

vivitrol and pregnancy

Studies on the matter are limited. On the one hand, naltrexone and pregnancy use has been shown to reduce neonatal abstinence syndrome in the baby. On the other hand, it isn’t clear how detoxing from alcohol or opioids—necessary for Vivitrol pregnancy therapy—can impact the fetus. Low dose naltrexone pregnancy therapy is considered safer than in higher doses, but more research is needed.

Side Effects On Women

Women who use Vivitrol while pregnancy can experience symptoms such as:

  • naltrexone weight loss
  • naltrexone anxiety
  • depression
  • higher rates of pregnancy complications than in the general population

Side Effects On Fetus

Side effects of naltrexone use on the fetus include:

  • reduced intrauterine growth
  • low birth weight
  • altered behavior as the child grows
  • increased rates of spontaneous intrauterine death
  • increased rates of birth defects

Ultimately, it is up to the woman and her doctor to determine if the naltrexone side effects are too risky to consider therapy during pregnancy.

Preventing Naltrexone Side Effects

The best way to prevent naltrexone side effects is to use the medication as directed. This means sticking to the prescribed dose and not mixing it with contraindicated substances. This can be hard for those using naltrexone for alcohol or drug abuse treatment, as they should avoid these substances yet are addicted to them.  Still, when considering the potential symptoms, abstaining from use and following directions is worth it.

Getting Help With Staying Clean

Anyone who is considering Vivitrol therapy for getting and staying clean should speak with a medical provider. Those at alcohol and drug rehab centers can guide patients in the use of Vivitrol while working on their skills for saying no to drugs and alcohol. With the right help, a good life is possible.

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Published on: June 7th, 2019

Updated on: June 24th, 2020

About Author

Olivier George, Ph.D.

Olivier George is a medical writer and head manager of the rehab center in California. He spends a lot of time in collecting and analyzing the traditional approaches for substance abuse treatment and assessing their efficiency.

Medically Reviewed by

Michael Espelin APRN

8 years of nursing experience in wide variety of behavioral and addition settings that include adult inpatient and outpatient mental health services with substance use disorders, and geriatric long-term care and hospice care.  He has a particular interest in psychopharmacology, nutritional psychiatry, and alternative treatment options involving particular vitamins, dietary supplements, and administering auricular acupuncture.


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