Warfarin

Description

Warfarin is an anticoagulant which is used to prevent the blood from clotting. You should inform the doctor if you have any bleeding disorder before taking this medicine and you should be aware of the possible side effects of this medicine. Close monitoring of liver and kidney function is necessary while receiving this medicine due to an increase in the risk of bleeding.

Side effects

Major & minor side effects for Warfarin

  • Abdominal pain
  • Blurred vision
  • Blood in urine and stools
  • Headache
  • Dizziness
  • Diarrhea
  • Skin rash and itching
  • Yellow colored eyes or skin
  • Muscle or joint pain
  • Excessive air or gas in stomach
  • Hair loss or thinning of the hair

Uses of Warfarin

What is it prescribed for?

  • Deep Vein Thrombosis
  • Pulmonary Embolism
  • Prophylaxis for Myocardial Infarction
  • Prevention of Thromboembolism in Atrial Fibrillation
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Concerns

Commonly asked questions

  • Onset of action
    The effect of this medicine can be observed in 36 to 48 hours.
  • Duration of effect
    The effect of this medicine lasts for an average duration of 2 to 5 days.
  • Safe with alcohol?
    Alcohol consumption is not recommended in patients receiving Warfarin due to an increase in the risk of bleeding. Close monitoring of prothrombin time and symptoms like excessive bleeding is necessary if alcohol is consumed with Warfarin.
  • Is it habit forming?
    No habit forming tendency has been reported.
  • Usage in pregnancy?
    This medicine is not recommended for use in pregnant women except in life-threatening conditions where the potential benefits outweigh the risks. Discuss all the risks and benefits with your doctor before taking this medicine.
  • Usage while breast-feeding?
    This medicine is recommended for use in breastfeeding women only if clearly needed. The risks and benefits should be discussed with the doctor before taking this medicine. If the medicine is used, close monitoring of the infant for any undesired effects is necessary.

Allergy

This medicine is not recommended for use in patients with a known allergy to Warfarin.

Central nervous system bleeding

This medicine is not recommended for use in patients with a head and/or spinal cord injury.

Bleeding disorder

This medicine is not recommended for use in patients who have a known history of bleeding disorders or an active bleeding disorder (inability of the blood to clot normally).

Gastrointestinal disorders

This medicine is not recommended for use in patients with a known history of gastrointestinal disorders like peptic ulcer disease or gastrointestinal bleeding due to an increase in the risk of further bleeding.
Warnings for special population

Pregnancy

This medicine is not recommended for use in pregnant women except in life-threatening conditions where the potential benefits outweigh the risks. Discuss all the risks and benefits with your doctor before taking this medicine.

Breast-feeding

This medicine is recommended for use in breastfeeding women only if clearly needed. The risks and benefits should be discussed with the doctor before taking this medicine. If the medicine is used, close monitoring of the infant for any undesired effects is necessary.
General warnings

Bleeding

Warfarin is known to cause severe bleeding. It is not recommended in patients with conditions like gastrointestinal bleeding, head injury, and patients about to undergo a surgery. Any symptoms of blood in the stools, vomiting blood, or blood in the urine should be reported to the doctor on priority. Close monitoring of prothrombin time is necessary while receiving this medicine.

Tissue Necrosis

Warfarin may cause tissue death within a few days of the treatment. Close monitoring of symptoms like pain and change in skin color is necessary while receiving this medicine. It is advised to stop the treatment if these symptoms appear. An alternate treatment option should be considered based on the clinical condition.

Calciphylaxis

Warfarin may cause a rare reaction called Calciphylaxis in which calcium is accumulated in small blood vessels of the fat and skin tissues. Close monitoring of symptoms like pain and change in skin color is necessary while receiving this medicine. It is advised to stop the treatment if these symptoms appear. An alternate treatment option should be considered based on the clinical condition.

Missed Dose

Take the missed dose as soon as you remember. If it is almost the time for your next scheduled dose, then the missed dose should be skipped.

Overdose

Seek emergency medical treatment or contact the doctor in case of an overdose.
All drugs interact differently for person to person. You should check all the possible interactions with your doctor before starting any medicine.
Interaction with Alcohol

Description

Consumption of alcohol will increase the concentration of Warfarin by inhibiting its metabolism and decreasing synthesis of clotting factors.

Instructions

Alcohol consumption is not recommended in patients receiving Warfarin due to an increase in the risk of bleeding. Close monitoring of prothrombin time and symptoms like excessive bleeding is necessary if alcohol is consumed with Warfarin.
Interaction with Medicine

Ethinyl Estradiol

Aspirin

Proton pump inhibitors

Fluoroquinolone antibiotics

Disease interactions

Bleeding disorders

Warfarin is not recommended in patients with a history of bleeding disorders or an active bleeding disorder (inability of the blood to clot normally) due to an increase in the risk of further bleeding. Replacement with a suitable alternative should be done under your doctor's supervision.

Liver Disease

Warfarin is not recommended in patients with a liver injury/disease due to an increase in the risk of bleeding. Close monitoring of liver function and symptoms like blood in the urine and stools, dizziness, unusual bleeding, etc. is necessary while receiving this medicine.
Food interactions
Information not available.
Lab interactions
Information not available.
Take Warfarin as advised by the doctor. Do not consume larger quantities than prescribed. This medicine is not recommended in patients with gastrointestinal bleeding, head injury, and low blood platelets level. Patients with liver injury/disease are advised to consult the doctor before taking this medicine.
Miscelleneous

Can be taken with or without food, as advised by your doctor

To be taken as instructed by doctor

Does not cause sleepiness

How it works
It prevents the blood from clotting by stopping the action of clotting factors.
Legal Status

Approved

Approved

Approved

Approved

Classification

Category

Anticoagulants

Schedule

Schedule H

[Internet]. 2017 [cited 12 July 2017]. Available from:

https://www.medicines.org.uk/emc/medicine/32630

DailyMed - Warfarin sodium tablet [Internet]. Dailymed.nlm.nih.gov. 2017 [cited 12 July 2017]. Available from:

https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3fb2aa58-3a40-4255-a261-e2db5b9a5dde

Prescribing medicines in pregnancy database [Internet]. Therapeutic Goods Administration (TGA). 2017 [cited 12 July 2017]. Available from:

https://www.tga.gov.au/prescribing-medicines-pregnancy-database

[Internet]. Toxnet.nlm.nih.gov. 2017 [cited 12 July 2017]. Available from:

https://toxnet.nlm.nih.gov/cgi-bin/sis/search2/f?./temp/~WVnstP:1

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Information on this page was last updated on 8 Jan 2018

Disclaimer

We’ve made all possible efforts to ensure that the information provided here is accurate, up-to-date and complete, however, it should not be treated as a substitute for professional medical advice, diagnosis or treatment. Practo only provides reference source for common information on medicines and does not guarantee its accuracy or exhaustiveness. The absence of a warning for any drug or combination thereof, should not be assumed to indicate that the drug or combination is safe, effective, or appropriate for any given patient. Practo does not assume any responsibility for any aspect of healthcare administered with the aid of information provided above. If you have any doubts about your medication then we strongly recommend that you consult with your doctor, nurse or healthcare provider. See detailed T&C here.