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What happens if you take opiates while on Vivitrol?

Medically reviewed by Melisa Puckey, BPharm. Last updated on March 22, 2023.

What happens if you take opiates while on Vivitrol?

Official answer


What happens when you take opiates while on Vivitrol is that you risk having overdose symptoms, organ and brain damage, coma or death.

Opiates should not be taken while on Vivitrol injection.

What is Vivitrol?

Vivitrol injection contains the active ingredient of Naltrexone which is used to treat alcohol dependence and opioid dependence.

How does Vivitrol work?

  • It works by blocking the receptor that the opiate usually binds to, so that if you use an opiate it will have a limited effect.
  • Or more simply you could think of the opiate as a key that goes into a keyhole which releases chemicals that give you the high that you are after. When you are given Vivitrol it acts like chewing gum being put into the keyhole, so it stops the opiate from working.

How does taking opiates with Vivitrol cause overdose?

By taking opiates with Vivitrol there are three ways this combination causes overdose:

  • If you take opiates while on Vivitrol you may not get the high effect from the opiate that you want. If you try to get high by taking a bigger dose of opiate, it may break the Vivitrol blockage causing a flood of opiates binding to receptors, which means you have a much bigger chance of overdose and death.
  • Another time you have a higher risk of opiate overdose is when you have been clean from opiate use for a while. Once you are not using opiates anymore you become a lot more sensitive to smaller doses, and for this reason if you use opiates again you may overdose on a dose that you would have been fine with before treatment. This is especially true to patients who have missed a dose of Vivitrol or have discontinued their treatment.
  • It is also really important to understand how the amount of Vivitrol in your body changes over the course of the month. When you first get the Vivitrol injection your blood levels initially are highest for the first 2 to 3 days, then after 2 weeks the blood levels slowly decrease. This means at the end of your 4 weeks before your next dose, you have less blockage of the receptors, so your body will be more sensitive to opiates. These changing levels of Vivitrol mean that if you use opiates over different times during the month, it can have unpredictable effects, which is risky. Towards the end of the 4 weeks you are at a greater risk of overdose as any opiate you use will have a bigger effect. It also means that a dose of opiate you used in the first week of Vivitrol treatment that didn’t harm you, might be enough to overdose at the end of the 4 weeks before your next shot, this is especially true if the next dose is late or you have discontinued treatment.

Bottom line:

  • You should NOT take opiates while on Vivitrol injection.
  • By taking opiates with Vivitrol you risk overdose, coma and death.

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