Pharmacy Program

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Your choice of the IHTC Pharmacy Program directly supports your IHTC team and patient services, and activities provided to the hemophilia community. The IHTC Pharmacy Program provides savings to you and your health insurance plan.

Every patient has the right to choose their clotting factor pharmacy provider. The IHTC supports your right of choice and will assist you in making an informed decision.

Clotting Disorders FAQ’s


What is a clotting disorder (thrombophilia)?

  • Thrombophilia describes a group of conditions (clotting disorders) in which there is an increased tendency for excessive blood clotting.
  • Clotting disorders can be due to inherited genetic abnormalities that are associated with a life-long increased tendency to clot.
  • Clotting disorders may also be associated with an acquired condition such as lupus anticoagulant or an antiphospholipid antibody, which can occur in persons either with or without systemic lupus erythematosus.
  • See IHTC’s webpages on Inherited Causes of Blood Clots and Acquired Causes of Blood Clots for further information on specific inherited and acquired clotting conditions.

Who can have a clotting disorder?

  • Clotting disorders affect a large number of people throughout the world.
  • Persons who experience episodes of blood clots, either as an isolated event or as repeated events, may have a clotting disorder.
  • Some people may have an identifiable disorder of clotting, such as factor V Leiden, yet not experience a blood clot.
  • Both men and women can have a clotting disorder.
  • Both children and adults can have a clotting disorder. Blood clots are more commonly diagnosed during the teen and adult years due to normal changes in the blood that occur with growth and aging.
  • Women who have a clotting disorder can have clotting problems during pregnancy or with the use of birth control pills or hormonal replacement therapy.
  • Factor V Leiden affects approximately 5% to 7% of white Americans of European descent.

Are all clotting problems inherited?

  • Not all clotting disorders are inherited. Clotting disorders can also be acquired, meaning they may develop at any time without an underlying genetic cause.
  • Some acquired clotting disorders are related to disease states that can be controlled or reversed, such as diabetes, high blood pressure, pancreatitis, inflammatory bowel disease, or obesity.
  • Healthcare providers are able to find out the cause of excessive clotting in some patients and families, but not in all cases. Further research is needed to understand why some individuals without an identifiable cause have clotting problems.
  • For more information on acquired causes of blood clots, click here.

What is thrombosis (blood clot formation)?

  • Thrombosis is the formation of a blood clot (also called thrombus) inside a blood vessel that blocks the normal flow of blood through the blood stream.
  • Blood clots may occur in either veins (blood vessels that deliver blood from the tissues to the heart) or arteries (vessels that deliver blood from the heart to the tissues).
  • A blood clot can reduce or completely shut off blood flow and oxygen to body tissues, resulting in pain, tissue damage and, in some cases, death.

What is an embolism?

  • An embolism occurs when part of a blood clot breaks off and travels in the blood stream to another part of the body, where it may block blood flow in the affected vein or artery.

Are there different types of blood clots in veins?

  • Yes. The most common types of clots in veins are deep vein thrombosis (DVT) and pulmonary embolism (PE)
  • DVT is the formation of a blood clot within one of the large deep veins of the body. It usually occurs in the deep veins of the legs or hips, although it can happen in other areas as well.
  • A PE occurs when a part of a deep vein clot breaks off and flows in the blood stream to the lungs. In the lungs, the embolized blood clot can block the blood vessels and reduce or prevent the flow of blood to the lungs.
  • PE is the most serious complication of DVT.

How common are blood clots?

  • Deep vein thrombosis (DVT) and pulmonary embolism (PE) are very common medical problems and are a significant cause of illness and death in the United States.
  • According to the CDC, 300,000–600,000 people in the United States have DVT or PE.
  • Of the people who have experienced a DVT, nearly one third develop postthrombotic syndrome a long-term condition that can cause disability. People with postthrombotic syndrome may have swelling, pain, discoloration, and scaling of the affected limb.
  • For some people, DVT may become a chronic illness. Approximately 30% of individuals who experience a DVT are at risk for having another episode.
  • An estimated 60,000 – 100,000 Americans die of DVT/PE each year.
  • It is important to note that DVT is preventable and treatable if diagnosed correctly and early.

What causes blood clots?

  • Blood clots are the result of three principal factors:
    • Pooling of blood in the deep veins
    • Damage to blood vessels
    • Increase in the activity of the components in the blood that are part of the normal clotting process. This increased activity leads to a super-clotting state (known as hypercoagulability)
  • Several factors can help cause the conditions listed above, thereby increasing the risk of a blood clot:
    • Inherited (genetic) abnormalities that cause an increased tendency to clot
    • A surgical procedure
    • Sitting or lying down for long periods (more than 4 hours)- for example, after surgery or on long plane or car rides. This lack of movement reduces blood flow in the legs by 50%.
    • Major injury
    • Increasing age
    • Cancer
    • Heart failure
    • Pregnancy
    • Use of hormone therapy such as birth control pills or hormone replacement therapy
    • Having a history of DVT
  • Other risk factors for blood clots may include:
    • Diabetes, which leads to damage of the blood vessels
    • Obesity, where excess weight places pressure on veins and causes them to weaken
    • Pregnancy and childbirth, where physical strain places pressure on deep veins, causing them to weaken
    • Tobacco smoking, which is associated with damage to blood vessels and doubles the risk of blood clots

Can blood clots be prevented?

Some blood clots can be prevented through physical activity, a healthy lifestyle, and quality medical care. Some important tips for preventing blood clots include the following:

  • Take breaks and stretch your legs when traveling long distances
  • Perform heel-toe exercises when seated during prolonged travel and get up and walk as frequently as possible
  • Drink fluids, preferably water, especially during prolonged travel
  • Know the symptoms of blood clots and seek early medical attention if they occur
  • Know the risk factors for blood clots and make lifestyle changes, such as stopping smoking, weight control, control of cholesterol and blood pressure
  • Be aware of a family history of blood clots
  • In case of major surgery, injury, prolonged immobility, or when in a cast, ask your healthcare provider whether you should receive treatment to prevent blood clots (DVT prophylaxis) and, if so, for how long.
  • In some cases, people at high-risk for blood clots or with a history of excessive clotting may be prescribed long-term anticlotting medicines (pills) to prevent a blood clot.
  • For optimal clot prevention, it is important that patients take their clotting medications as prescribed.


What are the symptoms of a blood clot?

  • The symptoms of a thrombotic episode relate to the location and size of the blood clot and whether the clot embolizes.
  • Some of the symptoms of a clot in the lungs (pulmonary embolism) include sudden shortness of breath, sharp chest pain, rapid heart rate, and unexplained cough, sometimes with bloody mucus.
  • Symptoms of a deep vein thrombosis in the legs include swelling, pain, and sometimes erythema in the affected area.
  • Individuals who experience an ischemic stroke (clot in the brain) may have a sudden headache, facial and/or limb numbness, and weakness and/or paralysis, particularly on one side of their body. Difficulty with vision, walking or maintaining balance also may occur. An individual with a stroke may appear to be confused and sometimes may experience a seizure or lose consciousness.

I had a large deep vein thrombosis (DVT) a few months ago. Is it normal for me to still have symptoms of swelling, pain, changes in skin color and varicose veins months after the clot?

  • Symptoms of chronic swelling, swelling with standing, redness, enlarged blood vessels, and pain are relatively common after a significant blood clot has occurred.
  • These symptoms are collectively referred to as postthrombotic syndrome (PTS). This syndrome may be present for months after the development of a clot or may become chronic if the first clot was large or if repeated clots occur.
  • Patients can manage PTS symptoms by:
    • Using a compression garment, often prescribed by a doctor to provide a specific amount of pressure
    • Standing and moving on a regular basis to encourage and maintain blood flow. Patients should talk to their healthcare provider regarding appropriate exercises
    • Avoiding long periods of standing still
    • Drinking plenty of fluid
    • Keeping the affected area raised as much as possible to encourage proper drainage in the veins
  • It may be difficult to know whether the symptoms of leg swelling are from a new clot or from PTS. Tests are available to help in distinguishing old from new clots.
  • Patients should inform their healthcare providers if their symptoms continue or change, or if they are concerned that a new clot may be present.
  • Healthcare providers can contact the IHTC toll-free at 1-877-256-8837 for further information or advice.


Why should people with a clotting disorder go to a hemophilia treatment center?

  • Hemophilia treatment centers (HTCs) provide comprehensive care for people with bleeding and clotting disorders.
  • HTCs are staffed by a range of healthcare providers, including hematologists, nurses, nutritionists, genetic counselors, physical therapists, and social workers, who work as a team to address the needs of persons with clotting disorders.
  • HTC providers help persons with clotting disorders better understand and manage their medical condition.

Do people with a clotting disorder need to see a specialist?

  • Many primary care providers manage patients with blood clots. However, if a patient has or has had a blood clot, it is recommended that they also be seen by a hematologist who specializes in the area of bleeding and clotting disorders.
  • Hematologists are an essential part of the HTC healthcare team. A hematologist accurately identifies and diagnoses clotting abnormalities that may contribute to the development of a clot. Accurate diagnosis is essential to the health of patients and families.
  • Hematologists have extensive experience in the management of anticoagulation. Appropriate choice of an anticoagulant, and the level and duration of anticoagulation are based on each patient’s diagnosis and individual circumstances, including the location and size of the clot, presence of factors that can “trigger” a blood clot, patient age, and family history.

If a patient has been diagnosed with factor V Leiden, should family members be tested, even if they have not personally experienced a blood clot?

  • If a patient has been diagnosed with an inherited clotting disorder such as factor V Leiden, his or her family members might also be affected and should be tested. Testing of family members allows for appropriate preventive healthcare management and for individuals to make informed decisions about their healthcare. This information may be helpful in medical decision making in certain circumstances, such as pregnancy, type of birth control utilized, and surgery.
  • Family members who might be at-risk for these conditions may visit a hematologist to have this testing performed.
  • Many HTCs provide this testing and education for affected individuals. In addition, the IHTC also has a genetic counselor who can explain this testing and the test results to patients and their families.

What can the IHTC do for you?

  • The IHTC’s anticoagulation clinic uses a multidisciplinary comprehensive approach to treating patients on anticoagulation therapy. Patients commonly are seen every 6 months by the anticoagulation clinic staff. The clinic is led by physician assistants experienced in the treatment of clotting disorders, with board-certified hematologists available for additional consultation. In addition, the IHTC’s physical therapist, registered dietitian, genetic counselor, and social worker provide support services on an as-needed basis. See our Meet the Staff page to read about how these healthcare professionals help providers and their patients who require anticoagulation therapy. The IHTC’s anticoagulation clinic is held weekly. For more information about the clinic, visit our clinic website or contact the IHTC at 317-871-0000 or toll free at 1-877-CLOTTER (1-877-256 8837).
  • The IHTC provides genetic counseling services for individuals with clotting disorders and their families. To contact our genetic counselor, please call the IHTC at 317-871-0000.
  • The IHTC’s registered dietitian provides information and advice on diet-related issues that affect anticoagulant medications, particularly warfarin (Coumadin® ). Visit the IHTC website on warfarin interactions for useful nutritional information, important dietary tips, and educational resources for providers who have patients on anticoagulant therapies.
  • Visit the IHTC’s Resources for useful educational websites and brochures on clotting disorders. The Resources page also provides links to educational presentations for healthcare providers.
  • The IHTC website provides education on clotting disorders for patients, their families, and healthcare providers to assist in all aspects of blood clot prevention and treatment.


When is Coumadin taken?

  • Coumadin should be taken daily at approximately the same time every day. It is often best to take this medication in the late afternoon or evening as this allows for dose adjustment if needed based on testing.
  • If patients forget to take a dose, they should contact their medical provider for specific instructions.

What medications should be avoided with the use of Coumadin?

  • There are many medications that may increase the anticlotting effect of Coumadin.
  • Unless specifically instructed by their healthcare provider, patients should avoid medications that affect the clotting system, such as aspirin, which has an antiplatelet effect.
  • Some antibiotics can affect the level of anticoagulation while on Coumadin.
  • Some people taking Coumadin who have a high risk of clotting also need to take antiplatelet agents. These drugs, like Coumadin, also interfere with the clotting mechanism. It is important to be aware of all medications a patient takes before initiating anticoagulation with Coumadin.
  • Herbal medicines, although available without prescription, may also affect the level of anticoagulation. For example, supplements that may affect clotting include ginseng, ginko biloba, bromelain, flaxseed, fish oil, vitamin E in large doses, garlic, ginger, and bilberry fruit. Be aware of any herbal medications patients may be taking. See also the IHTC’s webpage on Coumadin® interaction to learn about herbal products that may interact with Coumadin.
  • When patients take medications that may interact with Coumadin and affect the level of anticoagulation, the level of anticoagulation may need to be followed more closely to maintain the correct range.

Should patients avoid vitamin K foods while they are taking Coumadin?

  • Although Coumadin works through interference with the vitamin K pathway (which is important in making some of the body’s clotting factors), anticoagulation patients on Coumadin do not have to avoid all vitamin K-containing foods. These patients should, however, remember the following:
  • Eating large amounts of foods with vitamin K can reduce the effectiveness of Coumadin.
  • Patients should eat approximately the same number of servings of foods with vitamin K per day to maintain a consistent INR. For example, they should eat the same amount of green leafy vegetables every day.
  • Drastic changes in patients’ diets, such as trying to lose weight by eating more green leafy vegetables or cutting out all green leafy vegetables, will affect their level of anticoagulation.
  • Changes in diet may affect the level of anticoagulation. For example, eating more salad will decrease the INR (make clotting more likely) while cutting out vitamin K containing foods will increase the INR (make bleeding more likely).
  • For more nutritional information for people taking Coumadin, please see the information Coumadin® interactions with food on this website.

What is the PT/INR?

  • The prothrombin time, also referred to as the PT, measures the time needed for a clot to form in a tube of the patient’s blood after chemicals have been added to artificially activate the clotting reaction.
  • The PT is obtained either by blood drawn from the patient’s vein (venipuncture) or by an instrument that provides an INR result from a blood sample taken from a finger stick.
  • Because different laboratories use different reagents to perform the PT, results can vary between laboratories. Therefore, the PT was standardized through development of the International Normalized Ratio (INR) system so that results from different laboratories could be compared and interpreted. The INR is standardized only for the measurement of the effect of Coumadin on the PT to monitor therapy.
  • The INR is calculated to adjust for the varying sensitivities of diverse reagents used in different laboratories.

How often should a patient’s anticoagulation level be monitored?

  • The frequency of monitoring needed for each patient depends on how well they respond to the Coumadin dose and other medical issues.
  • Some patients require weekly monitoring, while others with stable responses who require long-term therapy may be monitored every other week or once a month.

What information do I need to know about my anticoagulation?

  • Ask your healthcare provider to give you educational materials about the use and monitoring of Coumadin. They may also contact the IHTC (toll-free at 1-877-256-8837) for information.
  • You should be aware of your target INR range and the results of your tests.
  • You should maintain a record of your INRs values and Coumadin dose. This information will allow you to be a better partner in your healthcare.

When is a low molecular weight heparin (LMWH) more appropriate than Coumadin?

  • Healthcare providers may prescribe LMWH instead of Coumadin in a variety of situations. These situations include but are not limited to patients who:
    • Experience clotting events while on Coumadin
    • Are pregnant. Coumadin should NOT be used in pregnant women
    • Have new or very large clot
    • Are about to undergo surgery or dental work
  • The use of LMWH requires intensive patient education before start of therapy. This should be coordinated through your healthcare provider’s office. The IHTC can help provide patient education. Healthcare providers can reach the IHTC toll-free at 1-877-256-8837.

Can a patient who is taking Coumadin still get a clot?

  • It is possible for patients to develop a blood clot while taking Coumadin.
  • If the INR is not in the target range and the patient is not being anticoagulated enough, a clot may occur.
  • A change in the brand of warfarin may lead to fluctuations in the INR. If the INR is not in the target range, a clot may occur.
  • Other variables, such as the presence of an underlying cancer, may place patients at risk of developing a clot, even if the Coumadin is taken as prescribed and the INR is within the target range.
  • Patients should contact their healthcare provider’s office or the IHTC (toll-free at 1-877-256-8837) with questions or concerns.
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