What Should I Eat If My Inr Is High? High INR indicates blood clotting due to which blood does not flow smoothly from one point to another. A clot causes blockage in the blood vessels ultimately leading to heart attack or stroke. It is usually seen with patients who are taking drugs for their diabetes or anti-clotting drugs for their heart disease. If you’re seeing high prothrombin INR, it could mean that you are at risk for bleeding.
International normalised ratio (INR) test
What is being tested?
An INR test measures the time for the blood to clot. It is also known as prothrombin time, or PT. It is used to monitor blood-thinning medicines, which are also known as anticoagulants. The INR, or international normalised ratio, can also be used to check if you have a blood clotting problem.
Prothrombin is a protein produced by the liver. It is one of several proteins, known as clotting factors, that help the blood stay at the right consistency. The INR test measures this clotting factor by measuring how long it takes for the blood to clot.
Why would I need this test?
Blood-thinning medicines such as warfarin are used to prevent blood clots. Warfarin is usually prescribed for people who have atrial fibrillation (where the heart beats unevenly) or who have had artificial valves fitted. How well warfarin is working is measured by how it increases the blood clotting time. So if you are taking warfarin you might need an INR test.
Blood thinning medicines don’t actually make the blood thinner. They work by increasing the time it takes for the blood to clot.
Your doctor can use an INR test to make sure the warfarin dose is right for you.
Blood clotting helps the body stop bleeding. But blood clots can also cause strokes or heart attacks. The INR test helps balance the risk of internal bleeding against the risk of blood clotting.
This test can also be used to:
- check for bleeding conditions
- check for blood clotting problems, especially before surgery
- check how well your liver is working
What Does a High INR Mean?
Warfarin (Coumadin) is a common medication that people take to prevent their blood from clotting. And if you are one of these people, you know that you need to get frequent blood tests to check your international normalized ratio (INR). This test indicates how long it takes your blood to clot. The higher the INR number, the longer it takes the blood to clot (or the “thinner” the blood).
For most people on warfarin, the target INR is between 2 and 3. But it is common for that number to rise over 3 — even without any changes to your dosage. And this can put you at risk for dangerous bleeding. We’ll explain why this happens, what to do if it happens to you, and some ways to prevent it.
What increases my INR levels?
It can sometimes be hard to keep your INR level within the target range. This is because there are a lot of factors — beyond your warfarin dose— that can increase the INR level. This is one of the reasons people need to repeatedly measure their INR when they’re taking warfarin.
Some of reasons that you might have an increase in your INR level include:
- Changes in dose: A higher dose may lead to a higher-than-expected INR.
- Medications: Lots of different medications can affect the INR. Changes to your other daily medications can affect the way your body processes warfarin. This can lead to a buildup of warfarin in your system and a high INR.
- Diet: Many foods can impact your INR level. Most of the time this is related to how much vitamin K is in your diet. Warfarin works by blocking the effect of vitamin K. So if you decrease the amount of vitamin K in your diet, this could lead to a high INR. And some experts believe that grapefruit can also lead to a high INR by affecting how the body metabolizes warfarin. But there is no hard evidence to prove this.
- Dietary supplements: Some supplements might have vitamin K in them, so changes to how you take these can affect the INR level.
- Alcohol: Drinking alcohol may lead to unpredictable changes in your INR.
- Herbal supplements: Many herbs can affect how your body metabolizes warfarin. St. John’s wort is a common example.
What are the symptoms of a high INR?
Most of the time, people will not have any symptoms when they have a high INR. But the problem with a high INR is that it can lead to serious bleeding. While bleeding might be obvious, such as from a wound or a nosebleed, there are some symptoms of bleeding inside the body to watch out for:
- Headaches might come from bleeding in the brain. This could happen on its own, or because of a head injury.
- Red, purple, or black stool can be a sign of bleeding in the gastrointestinal tract.
- Red or pink urine can also be a sign of internal bleeding.
If you have any signs of bleeding with a high INR, seek medical attention right away. We will go through this in more detail below.
What foods can interact with warfarin?
There are many foods and drinks that contain vitamin K. This section doesn’t include every dietary item that could possibly affect your INR level — just some notable ones. Be sure to discuss your regular diet with your healthcare provider when taking warfarin.
Dark, leafy green vegetables
Some of the most commonly consumed foods that are rich in vitamin K are dark, leafy green vegetables. Some examples of those include:
- Mustard greens
- Turnip greens
- Collard greens
- Swiss chard
- Brussel sprouts
If you’re worried you have to cut out these vegetables completely, don’t fret. Instead of avoiding eating leafy green vegetables, warfarin works best when the level of vitamin K in your body stays the same. So if you typically eat leafy greens, you can continue to eat your usual serving.
However, if you decide to change the amount of leafy greens you’re eating — either eating more or eating less — you need to let your provider know before making these changes. These adjustments in your diet can raise your risk of serious blood clots or dangerous bleeding while you’re taking warfarin.
Two beverages are often mentioned by healthcare providers when it comes to potential warfarin interactions — cranberry juice and green tea. However, the evidence is conflicting on how severe the interaction is between warfarin and these drinks. It’s always best to discuss this with your healthcare provider before adding or eliminating them from your routine diet.
Although cranberry juice contains little vitamin K, whether or not it interacts with warfarin is controversial. Some reports say taking cranberry juice and warfarin together can cause higher INR levels, which means a higher risk of bleeding.
On the other hand, studies have also shown that there is no interaction between the two. However, most experts agree drinking cranberry juice in moderation (about 8 fluid ounces per day or less) while taking warfarin shouldn’t affect your blood’s ability to clot.
In a case report, a person who drank large amounts (a half-gallon or more per day) of green tea while taking warfarin experienced low INR levels. This interaction has not been investigated further since this case report, so we don’t know if green tea would have this effect for everyone taking warfarin. However, moderate amounts of green tea contain little vitamin K and are not likely to affect warfarin.
Alcohol use can change the way warfarin works. Heavy drinking can change the level of warfarin in your body. Heavy drinking is defined as more than 7 drinks per week for people assigned female at birth and more than 14 drinks per week for people assigned male at birth.
Studies have found that episodic heavy drinking — occasionally drinking five or more drinks at a time — can raise the levels of warfarin and the risk of major bleeding, such as stomach or intestinal bleeding. On the other hand, excessive daily alcohol use has the opposite effect — it can lower the amount of warfarin in your body and raise your risk of clotting.
If you are going to drink, do so in moderation. The American Heart Association (AHA) recommends that people taking warfarin limit their alcohol consumption to no more than 1 to 2 drinks per day for people assigned male at birth or 1 drink per day for people assigned female at birth. But before drinking any alcohol with warfarin, it’s best to talk to your healthcare provider.
What vegetables can I eat while taking warfarin?
There are many vegetables that you can eat without worrying about whether you are eating it consistently or not. These vegetables are low in vitamin K and unlikely to affect your INR levels.
Some of these vegetables include:
- Green beans
- Red cabbage
Foods to limit while taking warfarin
If you suddenly start eating foods that have more vitamin K while you take warfarin, you may make warfarin less effective. If you suddenly start eating foods that have less vitamin K while you take warfarin, you may increase your chances of side effects from warfarin.
Foods that are rich in vitamin K include leafy vegetables. These may make warfarin less effective. Examples include:
- brussels sprouts
- collard greens
- mustard greens
- red cabbage
- green lettuce
You should also avoid drinking:
- green tea
- grapefruit juice
- cranberry juice
Green tea contains vitamin K and could lower the effectiveness of warfarin. Drinking grapefruit juice, cranberry juice, and alcohol during treatment with warfarin can increase your risk of bleeding.
Foods low in vitamin K
There are a variety of foods that are low in vitamin K that can help you create and enjoy a well-balanced diet.
Some vegetables and fruits low in vitamin K include:
- sweet corn
- sweet potatoes
- cucumbers (raw)
For a comprehensive list of foods containing vitamin K, visit the U.S. Department of Agriculture’s composition database.
What else can affect warfarin and how?
Substances other than food can also affect how well warfarin works. This effect is called an interaction. Sometimes these interactions can increase your risk of side effects from warfarin.
While you take warfarin, your doctor will check your blood regularly to see how well the drug is working for you.
Certain medications, supplements, and herbal products can affect how well warfarin works. Tell your doctor all the medications you’re taking before you start taking warfarin.
Some medications that can interact with warfarin include:
- antibiotics such as ciprofloxacin or fluconazole
- certain birth control pills
- certain drugs for seizures
- anti-inflammatory drugs such as ibuprofen
- antidepressants such as fluoxetine
- other blood thinners such as aspirin, clopidogrel, or heparin
- certain antacids
Interactions with food, medications, and other substances can also increase your risk of side effects from warfarin. The most common side effects of warfarin include:
- allergic reactions
- gastrointestinal disorders
- hair loss
- itchy skin
- inflammation of your blood vessels
- liver or gall bladder disorders
Some serious side effects of warfarin can include excessive bleeding from wounds and death of skin tissue. This is caused by small blood clots that block the flow of oxygen to your skin. Toe pain can be a symptom of skin death.