Naltrexone 25 mg 50 mg 380 mg IM

What is Naltrexone?

Naltrexone is a prescription medicine that blocks the effects of opioids and helps reduce alcohol cravings. It is used as part of a comprehensive recovery plan that can include counseling, mutual support, and practical relapse prevention steps. Two main forms are available. Oral tablets come in 50 mg strength and are taken daily, often after a 25 mg test dose. A long acting injection at 380 mg intramuscular once monthly is given by a clinician. People sometimes look for cheap generic tablets or buy refills online from licensed pharmacies to keep treatment consistent, but medical supervision is essential for safety.

Naltrexone does not cause euphoria, does not substitute for opioids, and is not a benzodiazepine. It is an antagonist that occupies opioid receptors so that if opioids are taken, their usual effects are blocked or greatly reduced. For alcohol use disorder, it reduces reward responses to alcohol and can lower the urge to drink or the amount consumed if a lapse occurs. The medicine is most effective when used with clear goals, a routine for taking doses, and support for handling high risk situations like weekends, social events, and stress spikes.

Starting naltrexone requires being opioid free to avoid precipitated withdrawal. Many programs check a timeline since last opioid use and may use a naloxone challenge or urine drug screen. People who rely on opioid pain medicines should discuss alternatives before starting because naltrexone will block pain relief. Wear a medical alert card or bracelet so emergency teams know you are taking an opioid blocker.

How It Works

Naltrexone binds to mu opioid receptors with high affinity and prevents opioids like heroin, oxycodone, or morphine from activating those receptors. By occupying the receptor, it reduces or blocks euphoria and respiratory depression if opioids are taken. For alcohol use disorder, the exact mechanism is multifactorial. By modulating the endogenous opioid system and downstream dopamine pathways, naltrexone lowers the reinforcing effects of alcohol so that urges are less intense and lapses are less rewarding.

With daily tablets, steady receptor blockade develops over several days and is maintained with consistent dosing. With the 380 mg injection, levels remain therapeutic for about a month, which can be helpful for people who miss oral doses or prefer not to think about medication every day. The medicine does not treat withdrawal and does not cure addiction. It helps create space where counseling, coping plans, and healthy routines can take root.

What this means day to day

Many people describe fewer intrusive urges by the second week. Social triggers feel duller, and a single stressful moment is less likely to cascade into a binge. If a slip happens, the episode is often shorter and easier to recover from. For those with prior opioid use, the blockade reduces experimentation because the expected effect is absent. This lowers the cycle of use and crash while other supports grow.

Dosage Information

Dosing is individualized and guided by a clinician. For alcohol use disorder, a common plan is 50 mg by mouth once daily, sometimes starting with a 25 mg test dose to assess tolerability. Alternative schedules such as 100 mg every other day can be used for adherence support, but daily dosing is most typical. For opioid use disorder relapse prevention after detoxification, the oral dose is similar. The long acting injection is 380 mg intramuscular once every 4 weeks given by trained staff. Do not attempt to self inject. People interested in convenience sometimes buy oral refills online from licensed pharmacies after a prescription is set, but injection scheduling must be arranged with a clinic.

• Opioid free requirement: Be opioid free for an adequate period before the first dose. Many programs require 7 to 10 days free from short acting opioids and longer for methadone or buprenorphine. A naloxone challenge may be used when the timeline is uncertain.
• Pain planning: Because naltrexone blocks opioid pain medicines, make a pain plan for dental work or surgery well in advance. Non opioid options can be effective when used in a coordinated way.
• Missed oral dose: If you miss a dose, take it when remembered the same day. If it is the next day, resume the regular schedule without doubling. Keep pillboxes or phone reminders to maintain consistency.
• Transition to injection: Many clinicians start with oral naltrexone to check tolerability before moving to the monthly injection.

For people seeking cheap options, generic oral tablets are usually less expensive than brand products. Mail order and licensed online pharmacies can reduce monthly costs while preserving pharmacist counseling. Always verify the strength, imprint, and expiration date on delivery.

Side Effects

Most people tolerate naltrexone well. Common effects include nausea, headache, dizziness, fatigue, anxiety, or trouble sleeping during the first days. These symptoms often improve as the body adapts. Taking the oral dose with a small meal can reduce stomach upset. With the injection, soreness or a firm lump at the site is common for a few days.

Less common but important

Liver irritation can occur. Watch for fatigue, loss of appetite, right upper belly pain, dark urine, or yellowing of the skin or eyes. Report these symptoms quickly. Rare injection site problems can include prolonged pain, swelling, hardening, or skin breakdown. Seek care if the area becomes very red, warm, or drains fluid.

Mood and safety signals

Changes in mood can appear in a minority of users. New or worsening depression, unusual irritability, or thoughts of self harm need immediate professional attention. For people with co occurring mental health conditions, close follow up improves safety.

Opioid sensitivity and overdose risk

Trying to override the blockade by taking high doses of opioids is dangerous and can cause overdose, especially as the medicine wears off. After stopping naltrexone, tolerance to opioids is reduced. A dose that seemed routine months ago can be life threatening. Carry a medical alert and inform family about naloxone availability for emergencies.

Warnings & Interactions

Do not start naltrexone if you are currently dependent on opioids or if you are in opioid withdrawal. Do not use during acute hepatitis or liver failure. People with moderate to severe liver disease need careful risk benefit discussion and lab monitoring. Verify that you can access non opioid pain strategies before surgery or dental work. Always carry a medical alert card that states you are taking an opioid antagonist.

Monitoring plan

• Before starting: Review last opioid use, perform a urine drug screen when appropriate, and consider a naloxone challenge. Obtain baseline liver tests including AST and ALT.
• During treatment: Recheck liver tests as directed, often at 1 to 3 months and then periodically. Review cravings, drinking patterns, or opioid lapse risks at each visit. Track sleep, mood, and energy.
• Safety kit: Keep naloxone in the home, even while on naltrexone, because overdose risk exists if someone attempts to override blockade or after stopping the medicine.

Drug interactions

Opioid containing medicines will be blocked and should be avoided unless an emergency plan is in place. Cough syrups, some antidiarrheals, and certain pain creams can contain opioids. Check every label and ask a pharmacist. No significant interactions occur with most antidepressants or anti anxiety agents, but report all medicines and supplements. If you plan to buy refills online, use pharmacies that provide full ingredient listings and access to pharmacist counseling.

Off label topics discussed with supervision

Low dose naltrexone for chronic pain or inflammatory conditions is an off label approach. It should only be considered under clinician supervision with clear goals and monitoring. Standard addiction treatment doses should not be altered without guidance.

Practical recovery supports

Set phone reminders for daily tablets, schedule injection appointments in advance, and line up counseling or peer support. Plan for high risk times such as paydays or holidays. Keep a simple urge log that notes time of day, trigger, and the coping step you used. If cost is a barrier, ask about generic tablets, assistance programs, or licensed options to buy medicine online safely. If you feel unwell, miss several doses, or consider stopping, contact your clinician promptly so you can adjust the plan without losing momentum.