Antithrombin III Deficiency

Antithrombin III Deficiency

What are these medicines? — These are prescription medicines that make your blood less likely to clot. "Oral" means medicine you take as a pill. There are other medicines that are given as a shot or through a thin tube that goes into a vein, called an "IV."
Medicines used to prevent or treat blood clots are also known as "anticoagulants" or "blood thinners." But they do not actually thin the blood.
There are several oral medicines used to prevent or treat blood clots. They include:
Apixaban (brand name: Eliquis)
Dabigatran (brand name: Pradaxa)
Edoxaban (brand names: Savaysa, Lixiana)
Rivaroxaban (brand name: Xarelto)
Warfarin (brand names: Coumadin, Jantoven)
Apixaban, dabigatran, edoxaban, and rivaroxaban are also called "direct oral anticoagulants." Each of these medicines blocks the function of a specific clotting factor. (Clotting factors are proteins in the blood that help it to clot.) Warfarin is also called a "vitamin K antagonist." It blocks the body's use of vitamin K in making some of the clotting factors.
Each medicine is different in terms of the dose, how often you take it, the cost, and how your diet or other medicines might affect it. The table answers some common questions about the differences (table 1).
What do I need to do if I take one of these medicines? — It depends on which medicine you take. Your medicine will come with specific instructions, and your doctor will talk to you about what you need to do. Below are some general tips:
Know the strength of your medicine, what the pills look like, and why your doctor prescribed it for you – The strength of the medicine is given in milligrams ("mg"). If the color, shape, or dose of your pills looks different from those you have taken before, check with your doctor or pharmacist.
Take your medicine exactly as your doctor tells you to – Take your medicine at the same time each day. How often you take it depends on which medicine you have and what you take it for. Dabigatran should be taken with a full glass of water after a meal.
Do not change your dose or stop your medicine without talking to your doctor. Always refill your prescription before you run out of pills. If you forget or miss a dose, call your doctor to find out what to do.
Use a pill box to stay organized – Some people find it helpful to use a weekly pill box (picture 1). This can help you keep track of your medicine and make sure you take all your doses.
One exception is if you take dabigatran. This medicine should not be stored in a pill box. You should always keep dabigatran pills in the original bottle or package they came in.
Get your blood tested when your doctor tells you to –If you take warfarin, you will need to have your blood tested often at first to check how your blood is clotting. This test is called a "PT and INR". This is important in order to make sure you get the correct dose of warfarin for you. Once you are on a regular dose, you do not need to have a PT and INR test as often, unless your diet changes, you get sick, or you start a new medicine.
If you take apixaban, dabigatran, edoxaban, or rivaroxaban, you will not need regular blood tests to check how the medicine is working. But your doctor might do a blood test once in a while to check your kidneys or liver.
Ask your doctor before taking any new medicines – This includes prescription or over-the-counter medicines, herbs, and vitamins. Certain medicines and remedies can change the way some of these medicines work. In particular, a lot of medicines can affect the way warfarin works. So it's very important to check with your doctor before taking any new medicines or stopping any medicines you already take.
Do not use medicines that contain an "NSAID" for treating pain or fever unless you talk to your doctor first. NSAIDs are a group of medicines that includes aspirin, ibuprofen (sample brand names: Advil, Motrin), and naproxen (sample brand names: Aleve, Naprosyn). They can increase your risk of bleeding, especially if combined with one of the medicines used to prevent or treat blood clots.
Also, make sure every doctor who prescribes anything to you knows that you take a medicine to prevent or treat blood clots and which one you take. That way, the doctor can check whether the new medicine might change the way it works.
Follow your doctor's instructions about diet – If you are taking apixaban, dabigatran, edoxaban, or rivaroxaban, there are not very many rules about diet. In some cases, rivaroxaban should be taken with food.
If you take warfarin, you will need to pay attention to the amount of vitamin K in your diet. You should eat about the same amount vitamin K from foods every day. Do not take vitamin K supplements unless your doctor tells you to. These things are important because vitamin K affects how warfarin works. If the amount of vitamin K in your diet changes from day to day, this can make warfarin not work as well. You do not need to avoid foods with vitamin K, as these are often healthy foods, and a bit of vitamin K is good. You just need to eat a similar amount of vitamin K from foods each day. Some leafy greens and other vegetables are high in vitamin K. The table lists the amount of vitamin K in other foods (table 2).
If you get sick, tell your doctor – If you have vomiting, diarrhea, a fever, or an infection, or if you cannot eat, tell your doctor. If you take warfarin, you might need a blood test and/or a change in dose.
Wear a medical alert tag – Always wear a bracelet, necklace, or alert tag (or carry a wallet card) that warns people that you take a medicine to prevent or treat blood clots and the name of the medicine. That way, if you are in an accident and are unable to explain your condition, people will know how to care for you. Your alert tag should also have the name and phone number of an emergency contact person.
If you might be able to get pregnant, talk to your doctor – These medicines are not recommended during pregnancy. If you take one of these medicines and might be able to get pregnant, talk to your doctor about birth control options. It's also important to tell your doctor right away if you get pregnant while taking one of these medicines.
What are the risks of these medicines? — The major risk is serious bleeding. That's because while these medicines help prevent dangerous blood clots, they also make it harder for your body to stop bleeding. This includes bleeding if you have an injury, but it could also be bleeding that happens without an injury. So it's important protect yourself from getting injured, and to get treatment as soon as possible if you have signs of bleeding.
Call your doctor right away if you:
Took more medicine than you were supposed to
Have a serious accident or fall, hit your head, or get another injury that could cause bleeding
Have any of these possible signs of abnormal bleeding:
•Feeling sick to your stomach or throwing up blood or something that looks like coffee grounds
•Blood in your bowel movements or dark-colored bowel movements
•Headaches, dizziness, trouble talking, weakness, or loss of function of one of your arms or legs
•Nosebleeds or any bleeding that does not stop
•Dark red or brown urine
You should also tell your doctor if you:
Bleed from your gums after brushing your teeth
Have heavy menstrual periods or bleeding between periods
Have more bruising than usual after a minor injury
Have diarrhea, vomit, or are unable to eat for more than 24 hours
Have a fever (temperature higher than 100.4°F or 38°C)
Cannot take your medicine for any reason
Is there anything I can do to lower my risk of bleeding? — Yes. You can:
Avoid doing things that could lead to a fall, such as walking on slippery surfaces or climbing on a high stool.
Avoid sports that might cause injury.
Use care when handling sharp tools, or avoid them when possible. Examples of tools that could cause serious bleeding if they cut you are sharp knives, saws, and straight edge razors.
Always use a seatbelt in the car, and wear a helmet if you ride a bicycle or motorcycle.
Avoid drinking a lot of alcohol, which can increase your risk of bleeding. If you drink, limit yourself to no more than 1 to 2 servings per day. A serving is equal to 1 beer (12 ounces), 1 glass of wine (5 ounces), or 1 shot of liquor (1.5 ounces).
If you need surgery, tell the surgeon you are taking a medicine to prevent or treat blood clots.
If you see a new doctor, dentist, or nurse, let them know you are taking a medicine to prevent or treat blood clots, and tell them which one.
For more detailed information about your medicines, ask your doctor or nurse for the patient hand-out from Lexicomp available through UpToDate. It explains how to use each medicine, describes its possible side effects, and lists other medicines or foods that can affect how it works.
All topics are updated as new evidence becomes available and our peer review process is complete.
This topic retrieved from UpToDate on: Mar 30, 2020.
Topic 86638 Version 20.0
Release: 28.2.2 - C28.105
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