Levomethadone

Levomethadone structure

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Levomethadone is a synthetic opioid used primarily in the treatment of opioid dependence and chronic pain. It is the levorotatory (left-handed) isomer of methadone, which means it is one of the two mirror-image forms of the methadone molecule. Levomethadone is known for its potent analgesic properties and is often preferred in clinical settings due to its efficacy and safety profile.

Pharmacology

Levomethadone acts as a full agonist at the mu-opioid receptor, which is responsible for its analgesic and euphoric effects. It also has activity at the delta-opioid receptor and kappa-opioid receptor, though to a lesser extent. The drug works by mimicking the action of endogenous opioids (such as endorphins) by binding to these receptors, thereby inhibiting the transmission of pain signals in the central nervous system.

Medical Uses

Levomethadone is primarily used in the following contexts:

• Opioid Dependence Treatment: It is used as a maintenance therapy for individuals with opioid dependence, helping to reduce withdrawal symptoms and cravings.
• Chronic Pain Management: Due to its potent analgesic properties, levomethadone is also prescribed for the management of severe chronic pain, particularly in patients who do not respond well to other opioids.

Dosage and Administration

Levomethadone is typically administered orally in the form of a solution or tablet. The dosage varies depending on the condition being treated, the patient's response to the medication, and other individual factors. It is crucial to follow a healthcare provider's instructions carefully to avoid the risk of overdose and other adverse effects.

Side Effects

Common side effects of levomethadone include:

• Nausea
• Vomiting
• Constipation
• Drowsiness
• Dizziness

Serious side effects may include respiratory depression, hypotension, and potential for abuse and dependence. Patients should be monitored closely for signs of adverse reactions, especially during the initial stages of treatment.

Contraindications and Precautions

Levomethadone should not be used in individuals with:

• Severe respiratory insufficiency
• Acute or severe bronchial asthma
• Known hypersensitivity to methadone or any of its components

Caution is advised in patients with a history of substance abuse, liver or kidney impairment, and certain cardiovascular conditions.

Mechanism of Action

Levomethadone's primary mechanism of action involves binding to and activating the mu-opioid receptors in the brain and spinal cord. This activation leads to the inhibition of pain signal transmission and modulation of the emotional response to pain. Additionally, levomethadone's effects on other opioid receptors contribute to its overall analgesic profile.

History

Levomethadone was developed as part of the ongoing efforts to find effective treatments for opioid dependence and chronic pain. Its development followed the synthesis of methadone during World War II, with subsequent research focusing on the individual isomers of the compound.

See Also

• Methadone
• Opioid
• Opioid dependence
• Chronic pain
• Mu-opioid receptor

References

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