Blood thinners reduce the blood’s ability to clot. These medicines also stop existing blood clots from getting bigger. However, they do not break up blood clots that have already formed. These medicines are also called anticoagulants (AN-te-ko-AG-u-lants).
It is important to get the right amount so your child’s blood is not too thin. We tell you warning signs of thin blood and regularly check how well your child’s blood is clotting. Once levels are stable, most kids are tested every 2 to 4 weeks. We check more often for babies who are growing quickly and less often for teens who are stable.
For families who don’t live in the Seattle area, our specially trained pharmacists help you find the closest lab for follow-up blood testing.
These blood thinners are the most common:
- Enoxaparin (Lovenox®). Your child gets this medicine as an injection under the skin.
- Warfarin (Coumadin®), given in pill form. Before starting an oral medicine, doctors would give your child enoxaparin or heparin for at least 5 days. This is called “bridging.”
- Heparin, through an IV tube. Doctors use this medicine if the clot needs quick treatment because of its size or location or if your child is scheduled for surgery. Your child would stay in the hospital for treatment.
We treat most new clots with enoxaparin. Children who need treatment for more than 3 months usually switch to medicine in pill form, such as warfarin.
Most children stay at the hospital overnight at the start of treatment for a new clot. During this time, we watch closely to see how the treatment is working. We teach parents about giving injections.
Novel oral anticoagulants (NOACs) are newer types of anticoagulants for adults that are not regularly used in children. Seattle Children’s is studying 1 of these medicines in children. Your doctor will talk with you about the study if it may be appropriate for your child.