Zum Hauptinhalt springen

Kann ich Warfarin und Methotrexat zusammen einnehmen?

Leitfaden zu Arzneimittelwechselwirkungen

Taking methotrexate while on warfarin can significantly increase your risk of bleeding. This might show up as unusual bruising, nosebleeds, bleeding gums, or in more serious cases, internal bleeding. It can also cause your blood-clotting tests (INR) to become unstable.

Taking Warfarin und Methotrexat together should be done with caution as taking them together can significantly increase your risk of bleeding.

You must speak to your doctor before taking these together. If you are prescribed both, you will need much more frequent blood tests (INR) to monitor how quickly your blood clots.

Lesen Sie unten weiter

Warum das passiert

Methotrexate can displace warfarin from the proteins in your blood that normally carry it, leaving more 'active' warfarin to thin your blood.

Additionally, methotrexate can sometimes affect how the liver processes warfarin and may cause damage to the lining of the stomach or gut, which increases the risk of a bleed starting.

You may be experiencing an interaction between warfarin and methotrexate if:

  • You notice unusual bruising or bleeding, such as nosebleeds or bleeding gums.

  • You have blood in your pee (urine) or poo (stools), or have black, tarry poo.

  • You feel unusually tired, weak, or dizzy.

  • You develop mouth ulcers or a sore throat.

  • You have signs of infection, such as fever or chills.

  • Your blood tests show a raised INR or changes in blood counts.

Lesen Sie unten weiter

Wenn Sie eines der oben genannten Symptome haben, sollten Sie:

  • Contact your GP or anticoagulation clinic for advice as soon as possible.

  • Seek urgent medical help if you have heavy bleeding or bleeding that will not stop.

  • Do not stop taking warfarin or methotrexate suddenly unless advised by a healthcare professional.

  • Attend any blood tests arranged to check your INR or blood counts.

Tell your healthcare professional about all medicines, supplements, and herbal remedies you are taking.

Blutungsrisiko

Warfarin increases your risk of serious bleeding. You must seek immediate medical attention if you have a fall, a head injury, or notice signs of internal bleeding such as dark/tarry stools or coughing up blood.

Drug interactions (NSAIDs)

Do not take anti-inflammatory painkillers like ibuprofen or aspirin unless specifically prescribed. These can dangerously increase the levels of methotrexate in your blood or significantly increase your risk of a major bleed while on warfarin.

Schwangerschaft und Empfängnis

Methotrexate causes severe birth defects and miscarriage. Both men and women must use effective contraception during treatment and for at least 6 months after stopping. If you think you are pregnant, seek medical advice immediately.

Warfarin can cause serious harm to an unborn baby. You must use effective contraception while taking it and inform your doctor immediately if you think you are pregnant.

Infection and blood disorders

Methotrexate can suppress your immune system and bone marrow. You must report a sore throat, fever, or unexplained bruising/bleeding immediately, as these can be signs of life-threatening blood toxicity or infection.

Lung and Liver Toxicity - methotrexate

Contact your doctor immediately if you develop a persistent dry cough or shortness of breath, as this can indicate serious lung inflammation. Avoid alcohol as it increases the risk of liver damage.

Dosierungsplan

Methotrexate for inflammatory conditions must only be taken ONCE A WEEK on the same day. Taking it daily can be fatal.

Lesen Sie unten weiter

Alkohol

It is best to avoid or strictly limit alcohol while taking warfarin. Alcohol can affect how your liver processes the medicine, which may increase your risk of bleeding or cause your INR levels to become unstable. If you do drink, keep it to a minimum and do not binge drink.

It is best to avoid or strictly limit alcohol when taking methotrexate. Both methotrexate and alcohol can cause damage to the liver; combining them significantly increases the risk of serious liver toxicity.

Foods high in vitamin K (e.g. spinach, kale, broccoli, Brussels sprouts, asparagus)

Vitamin K helps your blood to clot, which works against warfarin. You do not need to avoid these foods entirely, but you must keep the amount you eat consistent. A sudden increase or decrease in vitamin K intake can change how well your warfarin works.

Koffein (Kaffee, Tee, Cola)

Large amounts of caffeine may reduce the effectiveness of methotrexate for certain conditions like rheumatoid arthritis. Monitor your symptoms if you consume high levels of caffeine.

Cranberry juice and Goji berries

Cranberry juice and goji berry products can significantly increase the blood-thinning effect of warfarin, leading to a higher risk of bruising or bleeding. It is best to avoid these while taking warfarin.

Grapefruitsaft

Grapefruit juice may increase the levels of warfarin in your blood, which can increase your risk of bleeding. It is best to avoid grapefruit juice.

Pomegranate juice

Some evidence suggests pomegranate juice may interact with warfarin and increase the risk of bleeding. It is best to avoid it.

Folic Acid (Vitamin B9) and Fortified Foods

While your doctor will likely prescribe a folic acid supplement to reduce side effects, you should avoid taking additional over-the-counter multivitamins containing folic acid or eating excessive amounts of foods highly fortified with folic acid without consulting your specialist, as it can interfere with how the medicine works.

Taking multiple medicines? Our Wechselwirkungs-Checker für Medikamente helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Haftungsausschluss

Diese Informationen dienen nur allgemeinen Bildungszwecken und sollten nicht als Ersatz für professionelle medizinische Beratung herangezogen werden. Konsultieren Sie immer Ihren Hausarzt, Apotheker oder einen anderen qualifizierten Gesundheitsfachmann, bevor Sie Entscheidungen über Ihre Medikamente treffen. Individuelle Umstände können variieren, und nur ein Gesundheitsfachmann, der Ihre Krankengeschichte kennt, kann personalisierte Beratung bieten.

Lesen Sie unten weiter

Artikelverlauf

Die Informationen auf dieser Seite wurden von qualifizierten Klinikern verfasst und begutachtet.

  • 25. Jan 2026 | Ursprünglich veröffentlicht
flu eligibility checker

Fragen, teilen, verbinden.

Durchsuchen Sie Diskussionen, stellen Sie Fragen und teilen Sie Erfahrungen zu Hunderten von Gesundheitsthemen.

Symptom-Checker für Patienten

Fühlen Sie sich unwohl?

Bewerten Sie Ihre Symptome online kostenlos

Abonnieren Sie den Patienten-Newsletter

Ihre wöchentliche Dosis klarer, vertrauenswürdiger Gesundheitsberatung - geschrieben, um Ihnen zu helfen, sich informiert, selbstbewusst und in Kontrolle zu fühlen.

Bitte geben Sie eine gültige E-Mail-Adresse ein

By subscribing you accept our Datenschutzrichtlinie. Sie können sich jederzeit abmelden. Wir verkaufen Ihre Daten niemals.