Anticoagulation and Antiplatelet Therapy

Anticoagulants and antiplatelets are used for the prevention and treatment of blood clots that occur in blood vessels.  Oftentimes, anticoagulants and antiplatelets are referred to as “blood thinners,” but they don’t actually thin the blood at all. These drugs slow down the body’s process of making clots. Their main function is to keep the patient’s blood from clotting or turning into solid clumps of cells. These drugs do this by interfering with either fibrin or platelets in the blood.

Blood clots consist of two main components:

  • Fibrin is a protein substance that is formed from fibrinogen, which is a soluble protein that in synthesized in the liver and found in the blood plasma. This enables the blood to clot. Blood must clot (hemostasis) in order to stop bleeding from injury or diseases that lead to hemorrhage/bleeding. Anticoagulants inhibit the creation of fibrin.
  • Platelets are cells within our blood that bind together to help the blood clot. Their main function is to stop us from bleeding to death. When the body is bleeding a signal is sent and the platelets respond by traveling to the area of the bleeding. Once they have arrived at the site of the hemorrhage, they grow long tentacles and resemble spiders or an octopus when viewed under a microscope. Before they are signaled for clotting, they are plate shaped. Antiplatelets prevent platelets from sticking together.

Fun Fact!

Clots that are formed in the vein are mostly made of fibrin. This includes the diagnoses that we see of deep-vein-thrombosis (DVT). However, clots in the arteries typically are formed with mostly platelets. This includes the arterial diagnoses we see such as arterial thrombus, brain thrombus and heart thrombus, to name a few.

Most Common Anticoagulant Drugs:

  • Eliquis (apixaban)
  • Coumadin (warfarin)
  • Xarelto (rivaroxaban)
  • Pradaxa (dabigatran)
  • Bevyxxa (betrixaban)
  • Savaysa (edoxaban)

Most Common Antiplatelet Drugs:

  • Aspirin
  • Plavix (clopidogrel)
  • Effient (prasugrel)
  • Brillinta (ticagrelor)
  • Aggrenox (dipyridamole/ASA)

For coding professionals, it is important to pick up the long-term current use of both anticoagulants and antiplatelets, and report with the appropriate ICD-10-CM diagnosis code. Taking these medications can require further labs, monitoring or testing.


—Long-term Current use of anticoagulant (see above for most common)


—Long-term Current use of antiplatelet (see above for most common)


—Long-term Current use of aspirin (aspirin has its’ own code)

How long does it take for anticoagulants to dissolve a blood clot?

This is a trick question! Anticoagulants do NOT dissolve blood clots. They only help prevent new clots from occurring, or existing clots from enlarging, but they do not aid in dissolving the old clot. The body will dissolve the clot naturally if it can be dissolved.

The length for taking these medications depends on the reason for needing to start them in the first place. They can prescribed for a few weeks or for the rest of your life. The site of the blood clot (if that is why they are prescribed) also helps to determine the length the medication will be needed.

Most Common Reasons Prescribed:

  • Blood clots or people that are at high risk for developing one
  • Pulmonary embolism
  • Atrial fibrillation
  • Heart attack/previous heart attack/acute coronary syndrome/angina
  • Heart disease/cardiomyopathy
  • Stroke/TIA
  • Presence of coronary stent
  • Post-surgical heart
  • Post-surgical vascular system
  • Peripheral vascular disease

Are there risks involved with taking anticoagulants and antiplatelets?

There are always risk to any medication and treatment, but the physician will weigh out the risk vs. benefit before starting the patient on either of these medications. The risk vs. benefit of prescribing an anticoagulant/antiplatelet is a very serious thought process. If the patient has a risk of falls or frequent falls, the decision may be to NOT begin the patient on an anticoagulant or antiplatelet. The chance of increased bleeding is very high in a patient on anticoagulants. Hemorrhage is the most concerning adverse effect of the medication in a patient on anticoagulants.

Signs & Symptoms to Look for:

  • Bleeding from nose or gums
  • Large bruises (especially if it forms a lump)
  • Pink or red colored urine
  • Blood in stool (dark red or black stool)
  • Vomiting blood or coffee ground looking material
  • Lack of clotting with a minor injury within an expected amount of time
  • Coughing up blood
  • Heavy periods

Remember for coding, if the patient is taking their medication as prescribed and develops an adverse reaction, such as bleeding, this is coded as an adverse reaction to the prescribed medication and not a poisoning. If the patient is NOT taking the medication as prescribed and hemorrhage or other issue occurs, this is coded as a poisoning.

The latest edition of AHA, Coding Clinic for ICD-10-CM/ICD-10-PCS has given direction to coders on reporting the diagnosis of traumatic head injury associated with enhanced bleeding due to patient’s Coumadin use.

Per the recent AHA Coding Clinic this is reported with the trauma code followed by the codes for hemorrhagic disorder due to extrinsic circulating anticoagulants along with the adverse effect of medication, and long term (current) use of anticoagulants. The example that is given is a patient with a subdural hemorrhage that is enhanced due to the patient’s use of Coumadin therapy. A Question that comes to mind for coders in cases like this is “is the bleeding due to the fall or the medications?” If it is not clear, a query will be needed for the physician to determine if this was due to trauma…like a cause and effect. Only the physician can make these decisions. It could be that the injury is not severe enough to have caused the subdural hemorrhage with only minor external injury and the subdural hemorrhage caused the fall. Since we can’t make assumptions, the physician will need to clarify if it is not clearly stated in the record.

Authored by Kim Boy, RHIT, CDIP, CCS, CCS-P

ICD-10-CM/PCS Coding Clinic,  First Quarter ICD-10 2021 Page: 4,sometimes%20completely%2C%20sometimes%20only%20partially.,reduces%20inflammation%20in%20the%20arteries.
ICD-10-CM Official Guidelines for Coding and Reporting FY 2021

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The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.

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