thoughtscape NP Psychiatry · Patient education
Naltrexone
Tablets / Vivitrol monthly injection
Help with alcohol cravings or staying off opioids. Starting safely matters as much as taking it regularly.
Draft for review · Clinical content has not been revalidated for this website.
The diagram shows a selected opioid target. Naltrexone is not an overdose antidote or protection from intoxication.
What it is used for
Can reduce heavy drinking and alcohol cravings as part of a treatment plan. It does not treat dangerous alcohol withdrawal.
Can help prevent a return to opioid use after detoxification. Tablets and the monthly injection have different starting instructions.
How it works
Blocks opioid effects and may reduce some of alcohol's rewarding effects. You can still become intoxicated or be harmed by alcohol.
Taking large opioid amounts to overcome the block can be fatal. Overdose risk also rises when the medicine wears off or is stopped.
What to expect over time
BEFORE STARTING
Your team checks recent opioid use. Even a small first dose can trigger severe withdrawal.
FIRST WEEKS
Nausea or headache may improve. Track cravings, use and day-to-day progress.
ONGOING
Keep follow-ups and monthly injection visits. Treatment length is individual, not a fixed deadline.
Taking your medication
Take tablets as prescribed, often once daily. Food may help nausea; ask before changing the dose or timing.
Vivitrol is given into a buttock muscle by a clinician, usually monthly. Do not inject it yourself; call if you miss a visit.
Before restarting after a break, tell your team about any opioid use. Do not use a test dose on your own.
When to get help
Call 911: trouble breathing, inability to wake, severe allergic symptoms, or immediate danger from suicidal thoughts.
Possible opioid overdose: give available rescue medicine as directed and call 911. Naltrexone does not reverse an overdose.
Get urgent advice: severe withdrawal, yellow skin/eyes, dark urine, persistent abdominal pain, or a worsening injection-site lump, wound, or dark skin.
Early side effects
Nausea, headache, dizziness, tiredness, sleep changes, and reduced appetite can occur. Avoid driving until you know your response, and never drive while impaired.
Other effects to discuss
An injection can cause soreness. Report severe pain, swelling, blisters, an open wound, or a reaction that worsens or does not improve. Report new depression or mood changes.
What to keep track of
Track doses, cravings, and side effects. Your team may check liver tests and kidney function. Tell them about new pain treatment or a return to opioid use before the next dose.
Before you start
Review every opioid, including pain pills, tramadol, fentanyl, buprenorphine, and methadone. Short-acting opioids usually require at least 7–10 opioid-free days; some medicines need longer. Do not stop treatment or plan a washout yourself. Tell your team about liver/kidney disease, pregnancy or breastfeeding; decisions are individualized. For Vivitrol, discuss bleeding problems and the alcohol-free starting plan.
Medicines & interactions
Opioids and common remedies
Some pain, cough, and diarrhea medicines contain opioids. They may not work normally and can cause dangerous problems. Check all prescriptions, over-the-counter products, and supplements with your team.
Surgery, dentistry, and emergencies
Carry a medication card and tell every treating clinician. Plan pain care early. Tablets and injections wear off differently; do not stop treatment or take extra opioids on your own.
Alcohol and other medicines
Naltrexone does not make drinking safe or cause disulfiram's alcohol reaction. Other medicines can add liver or dizziness risks. Sudden alcohol withdrawal can be dangerous if you are physically dependent; ask for a safe plan.
Everyday tips
Set realistic goals with your team. Counseling, peer support, and practical help can work alongside medication.
Keep rescue medicine such as naloxone available. Show someone close to you how to use it and when to call 911.
After time off opioids, an amount you once tolerated can be fatal, especially after missed injections or stopping treatment.
A return to drinking is a reason to contact your team and adjust support, not to hide it or automatically stop the medicine.
Your questions, answered
What if I miss a tablet?
Take it when remembered unless it is nearly time for the next. Skip rather than double. If you used opioids or missed several doses, ask before restarting.
What if I miss an injection?
Contact the clinic promptly. Tell them about any opioid use. Do not add tablets or arrange a catch-up dose without a plan.
Can I stop without tapering?
Usually no taper is needed, but first discuss cravings, pain care, overdose prevention, and what treatment comes next. The injection cannot be removed after it is given.
Should I feel it working?
It does not need to feel noticeable to help. Review changes in cravings, drinking, or opioid use and daily life. Persistent problems may need a different plan.
Storage & safety
Store tablets at room temperature in a secure place, away from children and pets. Never share. For an accidental ingestion or too much medicine, call Poison Control at 1-800-222-1222; call 911 for collapse or breathing problems.
About this information
For general information only; not a substitute for individualized medical advice. This sheet does not cover every risk or interaction. Ask your prescriber or pharmacist before changing how you take this medication.
Sources
Educational inclusion does not mean this medication or its indications are treated at this practice. Review the guide for your exact product with your prescriber or pharmacist.