Warfarin Sodium

Consumer Medicine Information

What is in this leaflet

This leaflet answers some common questions asked about MAREVAN. It does not contain all the available information about MAREVAN. This leaflet does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor has weighed up the risks of you taking MAREVAN against the expected benefits.

If you have any concerns about taking this medicine, ask your doctor or pharmacist.

Keep this leaflet with the medicine. You may want to read it again later.

What MAREVAN is used for

MAREVAN contains an active ingredient called “warfarin”. It helps to prevent blood from excessive clotting or forming harmful clots.

This type of medication is called an anticoagulant. Some people refer to anticoagulant medicines as “blood thinners”. Excessive clotting sometimes occurs when physical mobility is low. If excessive clotting is not treated, it can lead to serious health problems such as strokes or heart attacks.

Ask your doctor if you have any questions about why MAREVAN has been prescribed for you. Your doctor may have prescribed MAREVAN for another reason.

There are two brands of warfarin. They are called MAREVAN and COUMADIN. Do not swap from one brand to the other. You should not combine these brands.

There is no evidence that MAREVAN is addictive.

MAREVAN is only available with a doctor’s prescription.

Before you use MAREVAN

When you must not use it

Do not take MAREVAN during pregnancy. Taking MAREVAN during pregnancy may harm the developing baby. If you are considering becoming pregnant or it is possible for you to become pregnant while taking MAREVAN, tell your doctor who can help you weigh the benefits of taking MAREVAN against the possible risks.

Do not take MAREVAN if you have had an allergic reaction to:

  • Warfarin
  • Any of the other ingredients in MAREVAN listed at the end of this leaflet
  • COUMADIN (another brand of warfarin)

Some of the symptoms of an allergic reaction may include: itchy skin rash; difficulty breathing; swelling of the face and tongue.

Do not take MAREVAN if you have bleeding tendencies or abnormal blood cells. MAREVAN may make bleeding tendencies worse.

Do not take MAREVAN if you have moderate to severe high blood pressure. The risk of bleeding in this situation may be increased by taking MAREVAN.

Do not take MAREVAN after the expiry date (EXP) printed on the bottle. It may have no effect at all, or worse, an entirely unexpected effect if you take it after the expiry date.

Do not take MAREVAN if the packaging is torn or shows signs of tampering.

Before you start to use it

You must tell your doctor if you:

  • Are breastfeeding
  • Are going to have any dental treatment
  • Have recently had or are going to undergo any surgical procedures or operations
  • Are starting any sports activities that may result in traumatic injury
  • Are going to travel or go on holidays

Your doctor or pharmacist is best able to advise you about combining these situations with taking MAREVAN.

Tell your doctor if you currently have or have had any of the following health/medical conditions:

  • Liver, kidney or intestinal disease such as coeliac disease
  • High blood pressure
  • A deficiency in Protein C
  • An ulcer in your stomach or duodenum
  • Red or black bowel motions
  • Internal bleeding such as bleeding in the brain
  • Bleeding tendencies
  • Fits or convulsions
  • Thyroid problems
  • Heart problems
  • Psychiatric problems
  • Severe diabetes
  • Long-lasting infections,diarrhoea, vomiting or fever
  • Alcoholism
  • Severe allergies

Your doctor will need to consider all these factors when advising you about taking MAREVAN.

Tell your doctor or pharmacist if you are taking any medications, including those you might buy from a chemist, health food shop or supermarket.

Some commonly used medicines and products that may interfere with MAREVAN include:

  • Aspirin
  • Any medication used to treat arthritis (including glucosamine and chondroitin)
  • Some medications used to treat blood clots, heart attacks or angina
  • Antihistamines or any cough or cold preparations
  • Some antibiotics
  • Laxatives
  • Vitamin C
  • Vitamin E
  • Vitamin K
  • St John’s Wort
  • Other herbal preparations (such as Garlic, Ginseng, Feverfew, Gingko biloba and Ginger)
  • Drinking alcohol
  • Cranberry juice
  • Eating large amounts of green leafy vegetables and/or drastic changes in dietary habits.

These may be affected by MAREVAN or may affect how well MAREVAN works. You may need to take different amounts of these or you may need to take something different.

Your doctor or pharmacist has a more complete list of medicines to avoid while taking MAREVAN.

If you have not told your doctor about any of these things, tell him/her before you take MAREVAN.

How to take MAREVAN

How much to take

You should follow your doctor’s directions exactly about how much MAREVAN to take. Different people require different amounts of MAREVAN and the dosage is adjusted to suit each patient. Your directions should be printed on the pharmacy label.

By using the results of a blood test, your doctor will decide what amount of MAREVAN you need. This means that your doctor may sometimes alter your dose of MAREVAN so that your dose is right for you.

When to take it

Take your medicine at about the same time each day. Taking it at the same time each day will have the best effect. It will also help you remember when to take it.

How to take it

Swallow MAREVAN with a glass of water. Do not crush or chew the tablets.

It does not matter if you take MAREVAN before or after food.

How long to take it

You may not feel any differently while taking MAREVAN from the way you were prior to taking it. However, MAREVAN will continue to be prescribed while there is a risk of excessive clotting.

Do not stop taking MAREVAN or reduce your dose unless your doctor advises you to do so.

If you forget to take MAREVAN

If you forget to take a dose of MAREVAN, tell your doctor immediately. Take the dose as soon as you remember and then go back to taking it as you would normally.

However, if it is almost time for your next dose (eg. within 8 hours), skip the missed dose and take your next dose when you were meant to.

Do not try to make up for a missed dose by taking more than one dose per day.

If you have trouble remembering when to take MAREVAN, ask your pharmacist for some hints.

If you take too much (overdose)

Immediately telephone your doctor or the Poisons Information Centre (telephone 13 11 26) or go to the casualty department at your nearest hospital if you think that you or anyone else may have taken too much MAREVAN, even if there are no signs of discomfort or poisoning. Keep the telephone numbers for your doctor, the Poisons Information Centre and your nearest hospital handy so that they are accessible in case of an emergency.

Possible signs of taking too many MAREVAN tablets include bleeding. Blood may be seen in stools or urine. Abnormal bruising or abnormal menstrual bleeding may also be experienced.

While you are using MAREVAN

Things you must do

Make sure that all of the doctors, dentists and pharmacists that are treating you know that you are taking MAREVAN. It is recommended that you also carry identification stating that you are taking MAREVAN.

Tell your doctor immediately if you become pregnant while taking MAREVAN.

Tell your doctor if, for any reason, you have not taken MAREVAN exactly as prescribed. Otherwise your doctor may think that MAREVAN was not effective and change your treatment unnecessarily.

Be sure to keep all of your appointments for blood tests so that the effect of MAREVAN can be checked.

Eat a normal, balanced diet. This minimises the possibility of dietary habits interfering with MAREVAN.

Things you must not do

Do not start or stop any other medicines while you are taking MAREVAN unless you have discussed this with your doctor. This includes medicines you can buy without a prescription from a pharmacy, supermarket or health food shop.

There are two brands of warfarin called MAREVAN and COUMADIN. Do not swap from one brand to the other. It may not be safe to change between these brands.

Do not take MAREVAN to treat any complaint other than that directed by your doctor. It may not be safe to take MAREVAN for another complaint.

Do not give MAREVAN to anyone else, even if their symptoms seem similar. It may not be safe for another person to take MAREVAN.

Side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking MAREVAN, even if you do not think the problem is connected with MAREVAN or it is not listed in this leaflet.

MAREVAN helps most people, but it may have unwanted side effects in some people.

Early notification to your doctor about such effects can help to prevent more serious complications by allowing for prompt adjustments in your MAREVAN therapy.

All medicines can have side effects. Medical treatment may be required for some side effects.

If any of the following occur after taking MAREVAN, immediately contact your doctor or the casualty department at your nearest hospital:

  • Bruising
  • Red or dark brown urine
  • Red or black bowel motions
  • Nosebleeds
  • Bleeding from gums after brushing
  • Vomiting or coughing up blood
  • Increased menstrual flow or heavier periods
  • Purplish & mottled toes
  • Prolonged bleeding from cuts
  • Swollen ankles
  • Painful swelling or discomfort
  • Stomach pain
  • Chest pain
  • Joint pain
  • Persistent headache or fever
  • Difficulty breathing or swallowing
  • Severe skin wounds
  • Persistent diarrhoea
  • A serious fall or injury

These are serious side effects. Urgent medical attention may be required to deal with these effects.

Tell your doctor or pharmacist if any other side effects occur while taking MAREVAN. Other side effects not listed above may also occur in some people. If this occurs, continue to take MAREVAN unless your doctor or pharmacist advises otherwise.

Ask your doctor or pharmacist to answer any questions you may have about side effects.

After using MAREVAN


Keep MAREVAN in the bottle until it is time to take it. If you take the tablets out of the bottle they may not keep well.

Do not store MAREVAN, or any other medicines, in the bathroom or near a sink. Heat and dampness can ruin some medicines.

Keep MAREVAN in a cool, dry place where the temperature stays below 30°C. Do not leave the tablets in the car or on a windowsill on hot days.

Keep it where young children cannot reach it. A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.


If your doctor tells you to stop taking MAREVAN, or you find that they have passed their expiry date, ask your pharmacist what to do with any unused medicine left over.

Product Description

What it looks like

MAREVAN tablets are available in three different strengths.

Each strength has a separate colour to distinguish it from the others. Be sure you are taking the right tablet by checking the colour and strength.

Each strength appears as follows:

  • 1 mg: round, brown, scored, bevelled edge tablet with “M” marked on one side above the score and “1” below the score and plain on the other.
  • 3 mg: round, blue, scored, bevelled edge tablet with “M” marked on one side above the score and “3” below the score and plain on the other.
  • 5 mg: round, pink, scored, bevelled edge tablet with “M” marked on one side above the score and “5” below the score and plain on the other.

Each bottle of MAREVAN contains 50 tablets.


MAREVAN tablets contain 1 mg, 3 mg or 5 mg of warfarin sodium as the active ingredient.

The other ingredients in MAREVAN are:

  • Lactose
  • Starch - Maize and Pregelatinized Maize
  • Sodium Starch Glycollate
  • Magnesium Stearate (470)
  • Iron Oxide Yellow (172) - in MAREVAN 1 mg
  • Iron Oxide Red (142) - in MAREVAN 1 mg
  • Indigo Carmine (132) - in MAREVAN 1 mg and 3 mg
  • Erythrosine (127) - in MAREVAN 5 mg

MAREVAN contains NO sucrose, gluten or tartrazine.

Further Information

If you have any further questions or if you are not sure about anything relating to the use of MAREVAN, your doctor or pharmacist can best assist you.

Contact the Poisons Information Centre on 13 11 26 for advice on management of overdose


MAREVAN is supplied in Australia by:
Sigma Pharmaceuticals Pty Ltd
(ACN 004 118 594)
96 Merrindale Drive
Croydon VIC 3136

Ph: (03) 9839 2800

MAREVAN Australian registration numbers:

  • 1 mg tablets:AUST R 12511
  • 3 mg tablets:AUST R 12513
  • 5 mg tablets:AUST R 12514

This leaflet was updated in March 2005, July 2006, September 2007 & September 2009.

Published by MIMS November 2010

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