Difference Between Naloxone and Naltrexone

The key difference between naloxone and naltrexone is that naloxone is used for emergency treatment for opioid overdose, whereas naltrexone is useful for long-term treatments of opioid-related disorders.

Naloxone and naltrexone are two types of very important medicine that are useful in treating disorders related to opioid intake.

CONTENTS

1. Overview and Key Difference
2. What is Naloxone
3. What is Naltrexone
4. Naloxone vs Naltrexone  in Tabular Form
5. Summary – Naloxone vs Naltrexone

What is Naloxone?

Naloxone is a medication that is useful in blocking the effects of opioids. This drug is sold under the trade name “Narcan.” This medication is useful for countering the decreased breathing in opioid overdose. Moreover, we can combine this drug with an opioid (as a single pill) to decrease the risk of opioid misuse. The routes of administration of this drug include endotracheal, intranasal, intravenous, intramuscular, and intraosseous pathways.

When this drug is administrated intravenously, the effect of the drug begins within about 5 minutes. There is another common method for administration; the method of spraying the drug into a person’s nose. Typically, the effects of this drug last for about 30 seconds to 24 hours. Since the duration of action of opioids is usually greater than the naloxone activity, we need to use multiple doses to block the effects of the opioids.

There can be some side effects of this medication, which include restlessness, agitation, nausea, vomiting, a fast heart rate, and sweating. In order to prevent these side effects, we can use small doses every few minutes until the desired outcome is obtained. The metabolism of naloxone occurs in the liver, and excretion occurs in the urine and bile.

When considering the chemical features of naloxone, the chemical name for this drug is N-allylnoroxymorphine. It is a synthetic morphinan derivative that originates from oxymorphone (an opioid analgesic that is derived from morphine). Moreover, the chemical half-life of this medication is around 24 months to 28 months.

What is Naltrexone?

Naltrexone is a medication useful in managing alcohol or opioid use disorder by reducing cravings and feelings of euphoria. This drug is sold under the trade names “ReVia” and “Vivitrol.” Moreover, we can find this medication is effective in treating other addictions, and we can also use it off-label.

However, a person that is dependent on opioids should not take this medicine before detoxification. The routes of administration of this drug include oral administration, intramuscular injection, and subcutaneous implant. Usually, the effects of naltrexone begin within 30 minutes of administration. Metabolism of naltrexone occurs in the liver, and excretion is through urine.

There can be some side effects of using this drug, including trouble sleeping, anxiety, nausea, and headache. However, this drug is not suitable for people with liver failure. We can identify this medicine as an opioid antagonist, and its mode of action is through the blocking of the effects of opioid that comes from both inside and outside the body.

We can describe naltrexone as substituted oxymorphone where the tertiary amine methyl-substituent is replaced with methylcyclopropane. Moreover, we can describe naltrexone as the N-cyclopropylmethyl derivative of oxymorphone. A similar molecule to naltrexone is nalmefene which has the same uses as naltrexone.

What is the Difference Between Naloxone and Naltrexone?

Naloxone and naltrexone are two types of very important medicine that are useful in treating disorders related to opioid intake. The key difference between naloxone and naltrexone is that naloxone is used for emergency treatment for opioid overdose, whereas naltrexone is useful for long-term treatments of opioid-related disorders.

The following infographic lists the differences between naloxone and naltrexone in tabular form.

Summary – Naloxone vs Naltrexone

Naloxone and naltrexone are two types of very important medicine that are useful in treating disorders related to opioid intake. The key difference between naloxone and naltrexone is that naloxone is used for emergency treatment for opioid overdose, whereas naltrexone is useful for long-term treatments of opioid-related disorders.

Reference:

1. “Naltrexone: Uses, Dosage, and Side Effects.” Drugs.com.

Image Courtesy:

1. “NaloxoneKit” By James Heilman, MD – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Naltrexone skeletal” By Fvasconcellos (talk · contribs) – Own work using: ACD/ChemSketch 10.0, Inkscape and vim (Public Domain) via Commons Wikimedia