What do you know about Levorphanol?

1. Mechanism of Action

• Opioid receptor activity: Levorphanol primarily works by binding to opioid receptors in the brain and spinal cord, specifically the mu-opioid receptors. It has agonist activity at mu, kappa, and delta opioid receptors, contributing to its analgesic effects.

2. Pharmacokinetics

• Long half-life:
  Levorphanol tablet has a relatively long half-life (11-16 hours), meaning its effects last longer than many other opioids like morphine. This prolonged effect can reduce the frequency of dosing

3. Clinical Uses

• Primarily used to manage moderate to severe chronic pain or cancer-related pain, particularly when other opioids are ineffective or poorly tolerated.
• Due to its NMDA antagonist properties, it may be particularly useful in treating neuropathic pain, a condition that is often difficult to manage with traditional opioids.

4. Side Effects and Risks

• Common opioid-related side effects include sedation, nausea, constipation, dizziness, and respiratory depression.
• Because it is a potent opioid, there is a significant risk of dependence, tolerance, and addiction with prolonged use.
• Like all opioids, overdose can lead to life-threatening respiratory depression.
• The long half-life can make it more challenging to adjust doses or stop therapy abruptly, potentially leading to prolonged withdrawal symptoms.

5. Comparison to Other Opioids

• Levorphanol tablet is more potent than morphine on a milligram-to-milligram basis, but its long half-life makes it more similar to methadone in terms of its pharmacokinetics.
• Due to its unique combination of NMDA antagonism and serotonin/norepinephrine reuptake inhibition, it may offer advantages in specific pain conditions, especially where tolerance to other opioids is an issue.

6. Dosage and Administration

• It is available in oral formulations, with dosing typically starting low and titrated slowly due to its potency and risk of accumulation.