INR: Liver Function Test Viral Hepatitis and Liver Disease

Warfarin was titrated up to the patient’s original regimen of 93.75 mg/week. His INRs were stabilized back into therapeutic range, and the patient did not restart consuming alcohol. Alcohol screening questionnaires, potentially coupled with genetic testing, could have clinical utility in selecting possible allergic reaction to beer patients for warfarin therapy, as well as refining dosing and monitoring practices. Healthcare providers use PT tests to check prothrombin levels, one of the coagulation factors that help form blood clots. A partial thromboplastin time test checks your plasma for coagulation factor abnormalities.

Coordination with a pharmacist, blood bank technician, and nursing staff are often required to quickly obtain and administer appropriate reversal agents and appropriately monitor response to therapy. Pharmacists can recommend dosing changes and/or reversal agents, which the nursing staff will deliver. Emergent bleeding can represent an “all hands on deck” situation, and coordinated care across professional lines is critical for efficient therapeutic action. Only by working together can the interprofessional healthcare tea minimize drug-drug interactions with warfarin and rapidly treat those that were not preventable, leading to optimal patient care.

Managing drug-drug interactions related to warfarin and its sequelae should involve an interprofessional approach involving laboratory technicians, nurses, pharmacists, and physicians. The first step in managing these interactions often comes at the time of warfarin prescribing. Physicians should work closely with pharmacists to avoid prescribing medications that have interactions. If these medications are essential, adjusting the patient’s warfarin dose may be necessary with close follow-up and monitoring early in the treatment regimen.

alcohol and inr

If you do drink as much as 14 units per week, it is best to spread this evenly over three days or more. If you have one or two heavy drinking sessions, you increase your risks of death from long-term illnesses, and of accidents and injuries. A variety of factors which affect the levels and patterns of alcohol consumption and the magnitude of alcohol-related problems in populations have been identified at individual and societal levels. Cove CL, Hylek EM. An updated review of target-specific oral anticoagulants used in stroke prevention in atrial fibrillation, venous thromboembolic disease, and acute coronary syndromes.

Review the agents that can either increase or decrease the anticoagulant effect of warfarin. However, here is information on why you should not drink when taking warfarin. If you are an occasional rare drinker, one or two on the holidays for example, isn’t a threat, just don’t schedule an INR test for days immediately after the holidays … Alcohol consumption by an expectant mother may cause fetal alcohol syndrome and pre-term birth complications. Alcohol consumption causes death and disability relatively early in life. In people aged 20–39 years, approximately 13.5% of total deaths are attributable to alcohol.


These actions render clotting factors inactive and unable to participate in the clotting cascade. Daily alcohol use of greater than three or more drinks will result in the possibility of several thing happening. First, the enzymes that metabolize the warfarin can become more active. This means that the INR test will show that you are not taking enough warfarin .

alcohol and inr

Dalteparin was continued as a bridge until the INR reached therapeutic range. Warfarin is one of the most popular drugs used to prevent and treat deep vein thrombosis . However, like any medication, how well it works for you is also affected by your lifestyle. If drinking alcohol is a part of your lifestyle, you may wonder how alcohol can affects your DVT and medication. This article will help shed light on how alcohol interacts with warfarin.

I don’t drink alcohol but my INR levels have increased and thought it might… My brother’s heart recently stopped, due to alcohol consumption, he survive… Unlike Bartle’s case report, this study showed no interaction between warfarin and grapefruit. The lack of interaction may be due to the fact that the CYP enzymes inhibited by grapefruit do not affect the more potent S-enantiomer of warfarin.

Reducing the burden from harmful use of alcohol

Some people’s attitude is, “If I cannot have a glass of wine with dinner, then I won’t take warfarin.” Taking warfarin in this case is probably better for you than not taking it. This study showed no significant difference between warfarin taken alone and taken with 296 mL wine during the fasting state in terms of one-stage prothrombin activity (both, 31%) and warfarin plasma levels (2.9 mic/mL vs. 3.0 mic/mL). Safety aspects were monitored (e.g., ecchymoses and bleeding), but no adverse events were reported. Patients were categorized as nonsmokers, light smokers, or heavy smokers.30 They were then subcategorized as taking a low, moderate, or high daily dose of warfarin . Comparison also was made between combined smokers and nonsmokers. Regimens were designed to maintain PT at twice the control level.

INR management in the therapeutic range remains a challenge, and hopefully, providers will be able to achieve optimal outcomes for their patients through clinical practice guidelines. Conventional coagulation testing can be performed in the laboratory setting to measure PT/INR. Warfarin’s hepatic metabolism and protein binding are the most common mechanisms for the occurrence of drug-drug interactions. Warfarin is metabolized via the cytochrome P450 system by CYP 2C9, 1A2, and 3A4. It is a racemic mixture, with the S-enantiomer being 2.7 to 3.8 times more potent than the R-enantiomer. Since the S-enantiomer is more potent and primarily metabolized by CYP 2C9, drug-drug interactions affecting this pathway may be more significant.

  • It is safest not to regularly drink more than 14 units per week, to keep health risks from alcohol to a low level.
  • This study showed no significant difference between warfarin taken alone and taken with 296 mL wine during the fasting state in terms of one-stage prothrombin activity (both, 31%) and warfarin plasma levels (2.9 mic/mL vs. 3.0 mic/mL).
  • Upon initiation of phenytoin, the INR may increase due to the displacement of warfarin from protein binding sites.
  • Our findings have important implications for selecting patients for warfarin therapy, as well as refining dosing and monitoring practices.
  • The recommended intake level of vitamin K for adult men is 120 micrograms .

INR monitoring is most commonly required for the patients who are on warfarin, a vitamin K antagonist. The dose of warfarin is adapted based on INR scores so that it remains in the therapeutic range to prevent thrombosis from subtherapeutic INR or hemorrhagic complications from supratherapeutic INR. The anticoagulant effect of warfarin indicated by an INR in the target range also guides us when to discontinue heparin. The patient’s INR was 2 upon admission, and warfarin was withheld.

Since warfarin is an anticoagulant, monitoring for signs and symptoms of bleeding such as black tarry stools, nosebleeds, or hematomas is imperative. Hemoglobin and hematocrit levels should be obtained before the initiation of warfarin and approximately every six months while taking warfarin. Other laboratory tests may be indicated based on a given patient’s presentation, including a urinalysis, occult blood, and liver function tests. Drug-drug, drug-herbal, drug-food, and drug-disease state interactions are all important factors that require monitoring to help avoid potential adverse effects related to supratherapeutic or subtherapeutic anticoagulation.

warfarin and alcohol

Your health care professional is the best source of information for questions and concerns related to your medical problem. Because no two people are exactly alike, and recommendations can vary from one person to another, it’s important to seek guidance from a health care professional who is familiar with your condition. Check with your health care professional if you plan to travel. While traveling, it’s important to always carry your medication with you.

It will also tell you how drinking can affect your risk of DVT. If there is serious liver disease and cirrhosis, the liver may not produce the proper amount of proteins and then the blood is not able to clot as it should. When your provider is evaluating the function of your liver, a high INR usually means that the liver is not working as well as it could because it is not making the blood clot normally. Healthcare providers often do this test to monitor your prothrombin levels if you’re taking the blood thinner warfarin (Coumadin®).

alcohol and inr

You’ve consumed food and drinks that can interact with warfarin, such as kale, spinach, cranberry juice and alcohol. To do this test, your healthcare provider will swab your skin with alcohol. Then, they’ll place an elastic band around your upper arm and ask you to make a fist. You may feel a sting or prick when your healthcare provider inserts the needle. After your healthcare provider has finished drawing blood, they’ll put a small bandage on spot where they inserted the needle. Talk to your health care provider before making major changes in your diet and before starting medications, vitamins or herbal supplements.

Prothrombin Time (PT) Test

INR of 2.0 to 3.0 is a general therapeutic range for people taking warfarin. Most laboratories report your PT test results as the international normalized ratio, or INR. Your INR result is a calculated measurement that adjusts for differences in laboratory testing processes. Typically, people receive their test results within a few hours to one day.

Due to complicated pharmacokinetic proprieties of warfarin, INR variability is expected within the first few days of initiation. The case below illustrates the complexity of warfarin dosing. Foods – Some foods can interfere with the effectiveness of warfarin. The most important point to remember is to eat what you normally eat and not to make any major changes in your diet without contacting your health care professional.

Content on HealthTap should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency. For patients early, mid, and late stages of alcoholism with an On-X mechanical bileaflet aortic valve with no other risk factors for thromboembolism, the INR goal is 2 to 3 for the first three months after valve surgery; and after three months the goal is 1.5 to 2. A feasibility study of continuing dose-reduced warfarin for invasive procedures in patients with high thromboembolic risk.

What’s the difference between a prothrombin time test and a partial thromboplastin time (PPT) test?

We demonstrate a strong association between alcohol misuse and major bleeding risk. You’re having surgery and your healthcare provider wants to confirm your blood clotting process functions as it should. Timely INR monitoring and patient-centered education on INR management is an integral part of patient care.

It’s important to tell all your health care professionals that you are taking warfarin. If you are having surgery, dental work or other medical procedures, you may need to stop taking warfarin. Never increase or decrease your dose unless told to do so by your health care professional. If you plan to travel abroad while on these medications, ensure you have an adequate supply for your stay. If effective treatments for alcohol use disorders you need to purchase these medications outside the U.S., first ask your health care professional to confirm the accuracy and quality of the medication. Clinical practice guidelines developed by the American College of Chest Physicians recommend educating and involving patients on INR testing, follow up, and result and dosing decisions that increase clinical benefit and cost-effectiveness.