Difelikefalin injection is used to treat itching in people with chronic kidney disease who are on hemodialysis (medical treatment to remove waste from the blood when the kidneys are not working properly). Difelikefalin is in a class of medications called kappa opioid receptor agonists. It works by changing the way your nerves respond to itching.

Difelikefalin comes as a solution (liquid) to be injected intravenously (into a vein). It is usually given at the end of each dialysis session by a healthcare provider.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Before you receive difelikefalin injection,

• tell your doctor and pharmacist if you are allergic to difelikefalin, any other medications, or any of the ingredients in difelikefalin injection. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had liver problems.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while receiving difelikefalin injection, call your doctor.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are receiving difelikefalin injection.
• you should know that difelikefalin injection may make you drowsy or dizzy. Do not drive a car, operate machinery, or participate in any other possibly dangerous activities until you know how this medication affects you.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

• dizziness
• drowsiness
• excessive tiredness
• sudden changes in mental status
• confusion
• vomiting
• pain, burning, numbness, or tingling in the hands or feet

Unless your doctor tells you otherwise, continue your normal diet.

Difelikefalin injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• diarrhea
• nausea
• dizziness
• problems with walking
• falling
• headache
• drowsiness
• sudden changes in mental status
• confusion

Difelikefalin injection may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Keep all appointments with your doctor and the laboratory.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.