WHY is this medicine prescribed?
Donidalorsen injection is used to prevent attacks of hereditary angioedema (HAE; genetic condition causing recurrent episodes of severe swelling). Donidalorsen is in a class of medications called prekallikrein-directed antisense oligonucleotides. It works by blocking the production of the protein that causes the swelling in patients with HAE.
HOW should this medicine be used?
Donidalorsen injection comes as a solution in an autoinjector (a prefilled syringe designed to autoinject a single dose of medicine) to be given subcutaneously (under the skin) by yourself or a caregiver. Give every 4 to 8 weeks as prescribed by your doctor.
Use donidalorsen injection exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Your healthcare provider will show you or your caregiver how to use the autoinjector. You will also be given instructions for use that come with step by step directions on how to give your injection. Ask your healthcare provider if you aren't sure on how to use the autoinjector.
Before injecting donidalorsen, remove the autoinjector from the refrigerator and let it warm to room temperature for 30 minutes. Do not try to warm by running under warm water, using a microwave, boiling or any other method. Inspect the autoinjector carefully to make sure the solution is clear and colorless to yellow. Do not use if there is cloudiness, particulate matter, or discoloration. Donidalorsen injection can be given into the abdomen or upper thigh. The back of the upper arm can be used if a caregiver is giving the injection.
Are there OTHER USES for this medication?
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What SPECIAL PRECAUTIONS should I follow?
Before using donidalorsen,
What SPECIAL DIETARY instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do IF I FORGET to take a dose?
Inject the missed dose as soon as you remember it and then schedule the next dose for 4 to 8 weeks later based on your prescribed dosing schedule.
What SIDE EFFECTS can this medicine cause?
Donidalorsen injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:
Donidalorsen injection may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
What should I do in case of OVERDOSE?
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at http://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.
What should I know about STORAGE and DISPOSAL of this medication?
Store donidalorsen autoinjectors in the refrigerator in its original packaging. It can also be stored at room temperature in its original packaging for up to 6 weeks. Do not freeze or expose to hear. Protect from exposure to light.
Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location - one that is up and away and out of their sight and reach. http://www.upandaway.org
Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website http://goo.gl/c4Rm4p for more information.
What OTHER INFORMATION should I know?
Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to donidalorsen.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.
This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.
The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.
AHFS® Patient Medication Information™ Copyright, 2025. The American Society of Health-System Pharmacists®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.
Selected Revisions: October 15, 2025.