Nalfurafine

Nalfurafine.svg

Nalfurafine is a pharmaceutical drug that acts as a kappa-opioid receptor agonist. It is primarily used in the treatment of pruritus (itching) associated with chronic kidney disease and liver disease. Nalfurafine is notable for its unique pharmacological profile, which allows it to alleviate itching without the typical side effects associated with other opioid medications, such as sedation and respiratory depression.

Pharmacology

Nalfurafine works by selectively activating the kappa-opioid receptors in the central and peripheral nervous systems. Unlike other opioids that primarily target the mu-opioid receptor, nalfurafine's selective action on kappa receptors helps to reduce the sensation of itching without causing significant euphoria or addiction potential. This makes it a valuable option for patients who require long-term management of pruritus.

Medical Uses

Nalfurafine is approved for use in several countries, including Japan and the United States, for the treatment of pruritus in patients undergoing hemodialysis or those with chronic liver disease. It is often prescribed when other treatments, such as antihistamines and corticosteroids, are ineffective.

Side Effects

Common side effects of nalfurafine include:

• Nausea
• Dizziness
• Fatigue
• Headache

Serious side effects are rare but may include:

• Hallucinations
• Confusion
• Severe allergic reactions

Mechanism of Action

Nalfurafine's mechanism of action involves the modulation of neurotransmitter release in the central nervous system. By binding to kappa-opioid receptors, it inhibits the release of substance P and other neuropeptides involved in the transmission of itch signals. This results in a reduction of the sensation of itching.

Development and Approval

Nalfurafine was developed by the Japanese pharmaceutical company Toray Industries. It was first approved for use in Japan in 2009 under the brand name Remitch and has since been approved in other countries for similar indications.

See Also

• Opioid
• Pruritus
• Kappa-opioid receptor
• Chronic kidney disease
• Liver disease

External Links

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