Stimate challenge


What is Stimate®?

Stimate® is a medicine that we can use to help stop bleeding in patients with von Willebrand disease and sometimes for patients with mild or moderate Hemophilia A. Stimate® is a nasal spray that contains the drug desmopressin acetate and provides 150 mcg per spray (1.5mg/mL).

How does it work?

Von Willebrand factor (VWF) is a protein in your blood that acts like glue with your body’s platelets to help your blood form a clot to stop bleeding. Some patients with von Willebrand disease do not have enough VWF. Other patients have enough VWF, but it does not work properly. VWF is stored in the platelets of the blood and in cells that line the blood vessels.

Stimate® helps to release VWF from where it is being stored, so that it is ready to be used in the body to stop the bleeding. It is like when you store toys in the closet until your child is ready to use them. Stimate® opens the doors to the closet (platelets) to take out a toy (VWF) so it can be used.

What is a Stimate® Challenge and why do we need to do one?

Stimate® may not work for everyone. We do a “Stimate Challenge” to make sure it will help your child stop bleeding. If it works, you can use it before your child has dental work or minor surgeries, and for bleeding episodes that do not respond to Amicar® (Aminocaproic acid). However, always talk to your hematologist (blood disorder doctor) before your child has any procedure that involves cutting the skin.

What should we expect during a Stimate® Challenge?

A Stimate Challenge will be done in the Medicine Room of the St. Jude Children’s Research Hospital Patient Care Center.

A nurse will take a sample of your child’s blood using a small butterfly needle. It will be sent to the lab to check for VWF antigen and activity levels, a factor VIII level and a platelet count. The needle will be removed after the blood sample is taken.

Stimate® comes as a nasal spray. Your child should blow her nose first then “sniff” the medicine up her nose. Patients who weigh less than 110 pounds (50 kg) will get one (1) spray (150 mcg) into the nose. Patients who weigh more than 110 pounds (50 kg) will get 2 sprays (150 mcg each); that is one (1) spray in each nostril.

After your child inhales the nose spray, you will wait about 30 minutes. Then, the nurse will take another blood sample with a small butterfly needle to check the same blood levels. This blood sample will be sent to a lab outside St. Jude. Our hope is that the Stimate® made the levels of VWF and Factor VIII in your blood increase. A hematology doctor or nurse practitioner will call you with the results in about 1–2 weeks.

You will be allowed to take home the remaining bottle of Stimate®, but do not let your child use it until you hear from the hematologist or nurse practitioner.

What results should we expect?

Two possible results can come from a Stimate® Challenge:

  • The Stimate® did not increase the levels of VWF and Factor VIII, which means it will not help stop bleeding in your child and cannot be used.
  • The Stimate® caused an increase in the VWF levels and Factor VIII. If this happens, the doctor will call you and tell you how your child should use Stimate® for bleeding or to prevent bleeding.


If you have further questions about von Willebrand disease, Hemophilia A, Stimate® or having a Stimate® Challenge, talk to your child’s hematologist or nurse practitioner.


This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.

St. Jude complies with health care-related federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex.

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