NALTREXONE

Naltrexone is an opioid antagonist used primarily in the treatment of opioid and alcohol dependence. It works by blocking the pleasurable and calming effects of opioids, helping to reduce cravings and prevent relapse. Naltrexone does not produce physical dependence and has no potential for abuse, making it a suitable option for long-term management of substance use disorders. Naltrexone received U.S. FDA approval in 1984 for opioid dependence and in 1994 for alcohol dependence. It is available in oral and injectable formulations. Oral tablets of 50 mg are commonly prescribed for daily maintenance therapy, while the extended-release injectable form administered monthly improves adherence, particularly in patients with difficulty maintaining daily dosing schedules. In India, naltrexone is prescribed routinely under psychiatric and addiction medicine practice, often integrated into comprehensive rehabilitation programmes.

Naltrexone is used for: Maintenance treatment in opioid dependence after detoxification Reduction of alcohol craving and relapse prevention in alcohol use disorder Adjunctive therapy in dual-diagnosis patients (e.g., substance use with mood disorders) Investigational use in conditions like compulsive behavior disorders and obesity

Naltrexone is typically administered as either a daily oral tablet (50 mg) or as a long-acting intramuscular injection (380 mg once a month). Oral dosing is often started after confirming that the patient is opioid-free for 7–10 days to avoid precipitated withdrawal. Patients are advised to take the oral dose at the same time each day to maintain consistent dose levels. The extended-release injectable formulation is administered by a healthcare professional into the gluteal muscle under sterile conditions. Regular follow-up and monitoring are essential to evaluate compliance and address any side effects.

Common Side Effects: Nausea or vomiting Headache or dizziness Fatigue or sleep disturbances Abdominal cramps or loss of appetite Joint or muscle pain Serious Side Effects: Liver toxicity (yellowing of skin or eyes, dark urine) Severe injection-site reaction (for extended-release form) Mood changes, depression, or suicidal thoughts Allergic reaction (rash, swelling, difficulty breathing) Unexplained bleeding or bruising

Do not use if the patient is currently dependent on opioids or has not completed detox; may precipitate severe withdrawal. Avoid in patients with acute hepatitis or liver failure. Not recommended for individuals with known hypersensitivity to Naltrexone or any of its components. Caution in patients with suicidal ideation or underlying psychiatric illness. The injectable form should be administered only by trained professionals to prevent injection-site reactions.

Before starting Naltrexone, make sure you haven’t taken any opioids for at least 7 to 10 days, as it can cause sudden and serious withdrawal symptoms. Your doctor will usually do a urine test to confirm this. Let your doctor know if you have any liver problems, are pregnant, breastfeeding, or planning to become pregnant. Regular blood tests may be needed to check your liver while using this medicine. Avoid taking any opioid-containing medicines, even over-the-counter ones, unless your doctor says it’s okay. If you're having surgery or need pain relief, tell the doctor you’re taking Naltrexone, as it blocks opioid painkillers. Also, carry a medical alert card or wear a bracelet to let emergency doctors know you’re on Naltrexone.

Naltrexone is a supportive medication, not a cure. For optimal outcomes, combine it with behavioural therapy, counselling, and a structured recovery programme. Do not attempt to overcome naltrexone's blocking effect by consuming large amounts of opioids—this can result in life-threatening overdose. Attend all scheduled follow-ups and inform your doctor of any changes in mental health. If side effects are serious or persistent, seek medical attention. Inform your healthcare provider of all medications you are taking to prevent interactions, particularly with medications metabolised by the liver.

https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/018932s017lbl.pdf https://www.ncbi.nlm.nih.gov/books/NBK534811/ https://www.drugs.com/naltrexone.html https://www.ncbi.nlm.nih.gov/books/NBK64042/