Generic Naltrexone (Naltrexone hydrochloride)

Introduction

Naltrexone (hydrochloride) is an opioid-receptor antagonist approved for the treatment of alcohol-dependence and opioid-use disorder. It is supplied as a 50 mg oral tablet and belongs to the medication group known as opioid antagonists. The drug is also employed in several well-documented off-label applications, such as low-dose naltrexone for certain autoimmune and chronic-pain conditions.

What is Naltrexone?

Naltrexone is the generic version of well-known medications, containing the active compound Naltrexone hydrochloride. Our online pharmacy provides this generic alternative as a cost-effective treatment option.

• Generic name: Naltrexone hydrochloride
• Brand names: marketed under brand names such as ReVia and Depade in various countries
• Classification: opioid receptor antagonist (μ-opioid receptor blocker)
• History: First synthesized in the s, FDA-approved in 1984 for opioid dependence and later expanded to alcohol-dependence.

How Naltrexone Works

Naltrexone binds competitively and reversibly to µ-opioid receptors in the central nervous system. By blocking these receptors, it prevents endogenous opioids (e.g., endorphins) and exogenous opioids (e.g., heroin, prescription analgesics) from producing their usual reinforcing effects.

• Onset: Approximately 1 hour after oral ingestion.
• Duration of action: 24 hours for the standard 50 mg dose, allowing once-daily dosing.
• Clearance: Primarily hepatic metabolism (CYP2D6, CYP3A4) with a half-life of about 4 hours; active metabolites extend pharmacologic effect to roughly 24 hours.

The blockade reduces cravings and diminishes the reward associated with alcohol or opioid-containing substances, supporting abstinence and relapse prevention.

Conditions Treated with Naltrexone

• Alcohol-dependence (Alcohol Use Disorder): Reduces the desire to drink and helps maintain abstinence when combined with counseling. FDA-approved based on multiple randomized controlled trials showing decreased heavy-drinking days.
• Opioid-use disorder (OUD): Prevents relapse after opioid detoxification by blocking the euphoric effects of opioids. The FDA approves oral naltrexone for patients who have completed medically supervised withdrawal and are opioid-free for at least 7-10 days.

These indications are supported by large-scale meta-analyses (e.g., Kranzler et al., 202; Lee et al., 2022) and incorporated into national treatment guidelines (American Psychiatric Association, 2022).

Off-Label and Investigational Uses of Naltrexone

• Low-dose naltrexone (LDN; 1-4.5 mg daily) for autoimmune diseases: Small-scale studies suggest modulation of the immune system via transient opioid-receptor blockade, leading to reduced inflammatory cytokines in conditions such as multiple sclerosis, Crohn’s disease, and rheumatoid arthritis.
• Fibromyalgia and chronic pain syndromes: Pilot trials report improvement in pain scores and quality of life when LDN is added to standard therapy.
• HIV-related immune activation: Limited research indicates possible reduction in inflammatory markers, though clinical benefit remains unproven.

These applications are not approved by the FDA, EMA, or other regulatory agencies. Use should occur only under direct supervision of a qualified healthcare professional, with careful monitoring for efficacy and safety.

Is Naltrexone the Right Medication for You?

Naltrexone is most appropriate for adults who:

• Have completed medically supervised detoxification from opioids and can remain opioid-free for ≥ 7 days.
• Meet diagnostic criteria for moderate to severe Alcohol Use Disorder and are motivated to reduce or cease drinking.
• Do not have acute hepatitis, liver failure, or severe renal impairment (eGFR < 30 mL/min/1.73 m²).

Contraindications include:

• Current opioid dependence or use (risk of precipitated withdrawal).
• Severe hepatic impairment (ALT/AST > 3 × ULN).
• Known hypersensitivity to the drug or any of its excipients.
• Pregnancy (category C) and breastfeeding (excreted in milk).

Patients with uncontrolled psychiatric illness, active infection, or those taking opioid analgesics for acute pain should discuss alternatives with their prescriber.

Risks, Side Effects, and Interactions

Common

• Nausea
• Headache
• Fatigue or drowsiness
• Dizziness, especially when standing (orthostatic hypotension)

Rare

• Insomnia or vivid dreams
• Elevated liver enzymes (monitoring recommended at baseline and periodically)

Serious

• Hepatotoxicity: Rare but documented; discontinue if transaminases exceed 3 × ULN.
• Severe allergic reaction: Rash, angioedema, or anaphylaxis.
• Precipitated opioid withdrawal: Can occur if opioid agonists are present in the system; may present with vomiting, tachycardia, hypertension, and agitation.

Drug-Drug Interactions

• Opioid analgesics: Immediate antagonism; may precipitate withdrawal.
• Alcohol: No direct pharmacokinetic interaction, but combined CNS depression can increase dizziness.
• CYP: Methadone, buprenorphine, or loperamide: Antagonized; dose adjustments or alternative therapies required.
• CYP2D6 inhibitors (e.g., paroxetine, quinidine): May modestly increase naltrexone plasma levels; monitor for enhanced side effects.

Drug-Food Interactions

• No specific food restrictions, but taking the tablet with a small amount of food can reduce gastrointestinal upset.

Use: Dosing, Missed Dose, Overdose

• Standard adult dose: 50 mg orally once daily. For alcohol-dependence, the dose may be initiated at 25 mg on days 1-3 to improve tolerability, then increased to 50 mg.
• Low-dose regimens (off-label): Typically 1-4.5 mg once daily, taken at bedtime. Only under specialist supervision.
• Missed dose: If a dose is missed and it is within 12 hours, take it as soon as remembered. If more than 12 hours have passed, skip the missed dose and resume the regular schedule. Do not double-dose.
• Overdose: Symptoms may include severe nausea, vomiting, respiratory depression (if combined with opioids), or coma. Seek emergency medical attention immediately; supportive care is the mainstay.

Practical precautions

• Avoid alcohol and opioid-containing medications while on naltrexone.
• Do not operate heavy machinery or drive until you know how the drug affects you, especially during the first few days.
• Store tablets at controlled room temperature (15-30 °C); keep out of reach of children.

FAQ

• What should I know about traveling with Naltrexone?

  • Keep the medication in its original packaging with a copy of the prescription or a physician’s note.
  • Pack tablets in a carry-on bag to avoid temperature extremes in checked luggage.

• Can Naltrexone affect drug testing for opioids?

  • Naltrexone itself does not produce a positive opioid screen, but its presence can interfere with interpretation of certain assays. Inform the testing laboratory of your medication.

• Does food impact the absorption of Naltrexone?

  • High-fat meals may slightly delay peak plasma concentrations; taking the tablet with a light snack is usually sufficient to minimize gastrointestinal discomfort.

• What is the appearance of the 50 mg Naltrexone tablet?

  • Typically a white, round tablet imprinted with “50” on one side; however, appearance can vary by manufacturer.

• Are there regional formulation differences?

  • Some countries include lactose or wheat-starch as inactive ingredients; patients with specific allergies should review the product label.

• How long does it take for liver enzymes to normalize after stopping Naltrexone?

  • In most cases, transaminases return to baseline within 4-6 weeks after discontinuation, provided no other hepatotoxic agents are used.

• Is Naltrexone safe for people with chronic hepatitis C?

  • Caution is advised; baseline liver function testing is required, and regular monitoring should continue throughout therapy.

• Can Naltrexone be used in combination with antidepressants?

  • No direct pharmacologic interaction is known, but both agents can cause fatigue or dizziness; monitor for additive central nervous system effects.

• What is the difference between Naltrexone and naloxone?

  • Naltrexone is a long-acting oral antagonist used for maintenance therapy, whereas naloxone is a short-acting injectable used acutely to reverse opioid overdose.

• Why does Naltrexone sometimes cause vivid dreams?

  • Transient blockade of opioid receptors can alter neurochemical pathways that influence sleep architecture, leading to vivid or abnormal dreams in a minority of users.

Glossary

Opioid Antagonist

A drug that binds to opioid receptors without activating them, thereby blocking the effects of opioid agonists.

Hepatotoxicity

Chemical injury to the liver resulting in elevated liver enzymes or impaired liver function.

Pharmacokinetics

The study of how a drug is absorbed, distributed, metabolized, and eliminated by the body.

Precipitated Withdrawal

An acute onset of withdrawal symptoms triggered when an opioid antagonist is given to a person who still has opioids in their system.

Buying Naltrexone from Our Online Pharmacy

Patients who encounter cost barriers, limited local stock, or privacy concerns can obtain Naltrexone through our online pharmacy.

• Affordability: We source the generic product directly from licensed manufacturers, allowing us to offer prices close to wholesale cost.
• Verified quality control: Every batch is inspected for authenticity and complies with international pharmacopeial standards.
• Discreet delivery: Packages are shipped in unmarked envelopes, with optional express (≈ 7 days) or standard airmail (≈ 3 weeks) services, ensuring privacy throughout the process.
• Global access: As a pharmacy-broker service, we partner with overseas licensed pharmacies, making international formulations available to patients who lack local options.

Our platform is built to provide a reliable, secure, and confidential channel for obtaining Naltrexone when conventional pharmacy routes are insufficient or overly costly.

Disclaimer

The information presented about Naltrexone is intended for general education only and does not replace professional medical advice. All therapeutic decisions, including those concerning off-label applications, must be undertaken under the supervision of a qualified healthcare provider. Readers are presumed to be responsible adults capable of making informed health choices. Our online pharmacy offers access to Naltrexone for individuals facing limited availability through traditional pharmacies or seeking affordable generic alternatives. Always consult a qualified professional before initiating, modifying, or discontinuing any medication.