How Long Does Naltrexone Stay in Your System?

Naltrexone can stay in your system for a variable amount of time. Depending on how you take naltrexone, it could be out of your system within one day or up to 30 days. Your addiction treatment specialist will recommend the best method for you to take naltrexone as part of your medication-assisted treatment (MAT) program.

Buckhead Behavioral Health offers MAT programs for addiction treatment in Atlanta, GA. Combining medications with behavioral therapy is one of the best ways to treat opioid and alcohol addiction. Naltrexone, and its injectable form, Vivitrol, can reduce the risk of relapse and overdose in early recovery from addiction. If you or a loved one are

What is Naltrexone?

Naltrexone is an FDA-approved medication to treat opioid use disorder as well as alcoholism. It can come in the form of a pill or an injectable medication (Vivitrol). Your prescribing physician will recommend the best way for you to take the medication.

When taken orally in pill form, naltrexone takes about one hour for the effects to work. However, the effects only last about a day, so you will need to take your pill daily. Injectable naltrexone, Vivitrol, lasts longer—up to about 4 weeks.

Therefore, the primary difference between oral and injectable administration is how long naltrexone will stay in your system. Regardless of how you take naltrexone, it works the same way to reduce cravings and prevent overdose.

How Does Naltrexone Work?

Naltrexone is an opioid antagonist and works by blocking the opioid receptors in your brain. This blocks you from feeling the effects of opioids like fentanyl, heroin, or codeine if you do relapse in early recovery. Since the opioid receptors are also activated by alcohol consumption, naltrexone also blocks the euphoric effects of alcohol.

By blocking the effects of opioids and alcohol, you won’t get the effects of these substances when naltrexone is in your system. However, excessive amounts of drugs or alcohol could potentially override the blocking effects of naltrexone. Still, naltrexone can prevent you from getting high or overdosing if you relapse in early recovery.

How Long Does Naltrexone Stay in Your System?

How long naltrexone stays in your system primarily depends on how you take the medication. If you take it orally, the effects will wear off within about one day. But, if you take Vivitrol injections of naltrexone, the effects can last about one month.

It is important to note, however, that Vivitrol injections wane in effectiveness as time increases from your last dose. You will need an injection about once every four weeks to keep it in your system. And, blood levels of naltrexone from Vivitrol injections will begin to decrease about two weeks after your shot.

Thus, no matter how you take naltrexone, you need to take it as prescribed to ensure it will remain effective.

Factors Affecting How Long Naltrexone Will Stay in Your System

In addition, other factors can affect how long naltrexone will stay in your system, including:

Metabolism: Your metabolic rate determines how quickly you process anything that you consume, including medication. So, if you have a fast metabolism, naltrexone will leave your system more quickly.
Age: Generally, older adults have a slower metabolism. That is why age can impact how long naltrexone will stay in your system.
Medication dosage: Your dosage of the medication is also a factor in how long the effects last. If the effects wear off too quickly and render naltrexone ineffective, you might need a higher dose.
Liver disease: Since the liver plays a significant role in processing medications if you have an underlying liver condition, you could have problems processing naltrexone. In addition, this could be a common issue among those using naltrexone for alcohol addiction because alcohol abuse impairs your liver health.
Method of administration: As mentioned previously, the effects of naltrexone pills wear off within about a day. Meanwhile, the effects of an injection can last nearly a month.
Medication frequency: The more often you take naltrexone, the longer the effects will last. That’s why it’s important to take your medication as prescribed and to stick to your injection schedule (for Vivitrol).

What Are the Side Effects of Naltrexone?

Every medication carries the risk of some side effects. To minimize some side effects, it’s important to detox from opioids or alcohol before taking naltrexone. Naltrexone isn’t meant to help you quit using substances. Instead, it helps reduce cravings and prevent overdose after you have gone through withdrawal symptoms.

Common side effects of naltrexone include the following:

Nausea and vomiting
Diarrhea
Abdominal pain
Trouble sleeping
Headache
Irritability
Drowsiness
Flu-like symptoms

Although rare, some side effects can be serious, such as:

Severe reactions at the site of injection (when taking Vivitrol)
Liver damage or hepatitis
Severe allergic reactions
Pneumonia
Depression

If you have serious side effects, get medical treatment right away. However, most people will only have mild side effects. As with any medication, consider if the pros of naltrexone outweigh the side effects before beginning medication-assisted treatment.

Get Medication-Assisted Treatment in Atlanta Today

Medication-assisted treatment (MAT) programs can help you stay sober during early recovery. At Buckhead Behavioral Health, we offer MAT with different medications, including naltrexone as well as its injectable form, Vivitrol. These medications can help to prevent relapse and reduce cravings when in recovery from opioid or alcohol addiction.