Heparin is used to prevent or treat certain blood vessel, heart, and lung conditions. Heparin is also used to prevent blood clotting during open-heart surgery, bypass surgery, kidney dialysis, and blood transfusions.

When should heparin be given?

When heparin is used to prevent blood clots from forming in intravenous catheters, it is usually used when the catheter is first put in place, and every time that blood is drawn out of the catheter or medication is given through the catheter.

When should you not give heparin?

You should not use heparin if you have uncontrolled bleeding or a severe lack of platelets in your blood, or if you have ever had low platelets caused by using heparin or pentosan polysulfate. Do not use heparin injection to flush (clean out) an intravenous (IV) catheter, or fatal bleeding could result.