Korsuva

About Difelikefalin

• Difelikefalin, is sold under the brand name called Korsuva. Difelikefalin was approved for medical use in the United States in August 2021. The U.S. Food and Drug Administration considers it to be a first-in-class medication.
• Korsuva is a kappa opioid receptor agonist approved for managing moderate-to-severe pruritus linked to chronic kidney disease (CKD-aP) in adults receiving hemodialysis (HD). It acts as a peripherally-restricted, highly selective agonist of the κ-opioid receptor (KOR).
• Difelikefalin acts as an analgesic by activating KORs on peripheral nerve terminals and KORs expressed by certain immune system cells. 
• Activation of KORs on peripheral nerve terminals results in the inhibition of ion channels responsible for afferent nerve activity, causing reduced transmission of pain signals, while activation of KORs expressed by immune system cells results in reduced release of proinflammatory, nerve-sensitizing mediators (e.g., prostaglandins).

Strength: 

The injection contains 65 mcg per 1.3 mL (50 mcg/mL) of Difelikefalin.

Recommended Dosage:

Ensure that Korsuva is not mixed or diluted before administering. Prior to administration, carefully inspect Korsuva for any signs of particulate matter or discoloration; the solution should be clear and colorless. Do not use Korsuva vials if any particulate matter or discoloration is observed. Korsuva is supplied in single-dose vials, and any unused product should be discarded. The injection volume to be administered depends on the patient’s target dry body weight in kilograms, allowing for flexibility in usage. Administer Korsuva through intravenous bolus injection into the venous line of the dialysis circuit at the end of each hemodialysis session. 

The dose can be given during or after the rinse back of the dialysis circuit. If administered after rinse back, inject Korsuva into the venous line followed by at least 10 mL of normal saline flush. If given during rinse back, no additional normal saline is needed to flush the line. Ensure that the dose is administered within 60 minutes of completing the syringe preparation and discard any unused product.

• Administer Korsuva injection at the recommended dosage of 0.5 mcg/kg through intravenous bolus injection into the venous line of the dialysis circuit after each hemodialysis treatment. 
• If a regularly scheduled hemodialysis treatment is missed, recommence Korsuva after the subsequent hemodialysis session.

Important:

Before commencing the Korsuva injection, promptly notify your doctor of any adverse reactions or unusual symptoms observed during treatment. Furnish detailed information about existing health conditions to ensure the safe administration of the medication. Transparent and open communication regarding your health is pivotal for personalized care and addressing any emerging concerns during treatment. Furthermore, divulge information about your current medications to prevent potential interactions, particularly for individuals with pre-existing conditions. This guarantees comprehensive care and minimizes associated risks. Provide details about the medications you are currently taking to avoid interactions.

Warnings & Precautions

• Dizziness, somnolence, mental status changes, and gait disturbances, including falls, have been reported. Exercise caution when using centrally-acting depressant medications, sedating antihistamines, and opioid analgesics during Korsuva treatment.
• There is a risk of impaired mental or physical abilities that may affect driving or operating machinery. 
• Patients should be advised not to drive or operate dangerous machinery until the impact of Korsuva on their ability to perform such activities is understood.

Common Korsuva Side Effects:

• Diarrhea
• Dizziness
• Nausea
• Trouble walking (including falls)
• High potassium (hyperkalemia)
• Headache
• Sleepiness
• Mental status changes, such as confusion

Use in Specific Population

• Inform your doctor if you are pregnant or planning to conceive, as the potential impact of Korsuva on unborn babies is currently unknown.
• Additionally, notify your doctor if you are breastfeeding or intending to breastfeed, as it is uncertain whether Korsuva is excreted into breast milk. Consult with your doctor to determine the most suitable feeding approach for your baby in case you are undergoing Korsuva treatment.
• The safety and efficacy of Korsuva in pediatric patients remain undetermined. No discernible variations in the safety or efficacy of Korsuva have been identified between patients aged 65 years and older and younger adults.
• Regarding hepatic impairment, a population pharmacokinetic analysis has indicated that no dosage adjustments for Korsuva are necessary for individuals with mild-to-moderate hepatic impairment. However, there is no evaluation of Korsuva’s pharmacokinetics in subjects with severe hepatic impairment undergoing hemodialysis, making its use in this population not recommended.

Storage and Handling

• Keep vials within the temperature range of 20°C to 25°C (68°F to 77°F), with allowable excursions to 15°C to 30°C (59°F to 86°F).
• Do not freeze the medicine. 
• Keep the medicine away from pets and children.