Advanced search

Report side effect

Report a suspected side effect or falsified product to the MHRA Yellow Card scheme.
Go to {yellow_card_logo} site
{arrow_up} Back to top

Sinthrome 1 mg Tablets

Active Ingredient:
Norgine Limited See contact details
ATC code: 
About Medicine
The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine.
Last updated on emc: 07 Dec 2022

Below is a text only representation of the Patient Information Leaflet (ePIL).

The text only version may be available in large print, Braille or audio CD. For further information call emc accessibility on {phone} 0800 198 5000. The product code(s) for this leaflet is: PL 20011/0068.

Sinthrome Tablets 1 mg

Package leaflet: Information for the user

Sinthrome® 1 mg Tablets


Read all of this leaflet carefully before you start taking this medicine because it contains important information for you

Always take this medicine exactly as described in this leaflet or as your doctor or pharmacist have told you.

  • Keep this leaflet. You may need to read it again.
  • If you have any further questions, ask your doctor or pharmacist.
  • This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours.
  • If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. See section 4.

What is in this leaflet

1. What Sinthrome is and what it is used for
2. What you need to know before you take Sinthrome
3. How to take Sinthrome
4. Possible side effects
5. How to store Sinthrome
6. Contents of the pack and other information

1. What Sinthrome is and what it is used for

Sinthrome 1 mg Tablets (acenocoumarol) belongs to a group of medicines called anticoagulants (blood thinning medicines).

Sinthrome is used to treat and prevent blood clots blocking the blood vessels e.g. deep vein thrombosis (DVT).

Sinthrome does not dissolve blood clots that have already formed but it may stop the clots from becoming larger and causing more serious problems.

2. What you need to know before you take Sinthrome

Follow all the doctor’s instructions carefully. They may differ from the general information contained in this leaflet.

  • Do not take Sinthrome if you: are allergic (hypersensitive) to acenocoumarol, or similar medicines to thin the blood called coumarin derivatives (e.g. warfarin, phenprocoumon), or to any of the ingredients in Sinthrome (see Section 6, Contents of the pack and other information)
  • are pregnant, planning to become pregnant or breast-feeding (see Pregnancy, breast-feeding and fertility).
  • are an alcoholic
  • have any mental illness for example, schizophrenia or dementia
  • have recently had, or are about to have an operation on your spine, brain, eyes or any major surgery
  • had a stroke caused by bleeding into your brain
  • suffer from very high blood pressure
  • have stomach ulcer or any intestinal bleeding
  • pass blood in your water or cough up blood
  • suffer from any bleeding disorders, bleeding problems or unexplained bruising
  • feel sharp pain in the centre or left side of the chest which may be accompanied by shortness of breath (these may be signs of a fluid buildup or inflammation around the heart called pericarditis) or if you experience flu-like symptoms, heart murmurs, rash and chest pain (these may be signs of infection of the inner lining of the heart called endocarditis)
  • have severe liver or kidney disease.

If any of the above applies to you, or if you are not sure, speak to your doctor or pharmacist before you take Sinthrome.

Warnings and precautions

Talk to your doctor or pharmacist before taking Sinthrome Tablets.

Before you take Sinthrome tell your doctor or pharmacist if you:

  • have cancer
  • have an infection or inflammation (swelling)
  • have a disorder affecting the absorption of food from the stomach and/or intestine
  • have heart failure (which causes swelling and shortness of breath) – this might reduce blood flow in the liver which in turn would reduce blood clotting
  • have liver problems – this might reduce blood clotting
  • have kidney problems – this could lead to the build up of the breakdown products of Sinthrome
  • have an overactive thyroid
  • are elderly
  • suffer from a blood disorder such as protein C or protein S deficiency – this would cause you to bleed for longer than normal after a cut or injury.
  • have a higher risk of bleeding for example if you have:
    • a history of variable blood test results for the international normalised ratio (INR)
    • a stomach or duodenal ulcer or have ever had one
    • high blood pressure
    • problems with circulation of blood to the brain (cerebrovascular disease)
    • anaemia
    • recent wound or injury
    • been taking any of the drugs mentioned below or have been taking Sinthrome for a long period of time

You should NOT receive any injections into your muscles whilst you are taking Sinthrome.

If you need any injections into your spine or as part of a scan or X-ray test or if you need minor surgery, including dental surgery, make sure you discuss your treatment with your doctor first.

If you are involved in an accident while on Sinthrome you are likely to bleed more than normal. The doctor or hospital staff must be informed that you are taking Sinthrome immediately. Always carry your personal anticoagulation card (an identification card from your pharmacist stating that you are using this medicine).

Calciphylaxis, a condition in which calcium builds up in blood vessels in the skin, sometimes happens when patients are taking blood thinning medicines including Sinthrome. This is rare, but it causes painful skin lumps or ulcers which can lead to serious infection and death. It usually only happens if a person has serious kidney disease, or if they already have something wrong with the levels of calcium, albumin, phosphate, or certain proteins, in their blood.

If any of the above applies to you, or if you are not sure, speak to your doctor or pharmacist before you take Sinthrome.

Other medicines and Sinthrome

Tell your doctor or pharmacist if you are taking or have recently taken or might take any other medicines, including medicines obtained without prescription (over-the-counter). This applies especially to the following medicines as they may interfere with Sinthrome:

Medicines that increase the activity of Sinthrome such as:

  • heparin (including a man-made form called low-molecular-weight heparin) - to thin the blood in the treatment of deep vein thrombosis, blood clots or after surgery
  • antibiotics (e.g. clindamycin)
  • salicylic acid and related substances (e.g. acetyl salicylic acid, aminosalicylic acid, diflunisal) (medicine used against pain)
  • medicines that stop platelets (these are particles in the blood that are involved in blood clotting) from clumping together (e.g. dipyridamole, clopidogrel, ticlopidine)
  • phenylbutazone or other pyrazolone derivatives (e.g. sulfinpyrazone), other non-steroidal anti-inflammatory medicines (these are used to reduce pain, fever and inflammation), including the ones that target a specific molecule called COX-2, e.g., celecoxib, methylprednisolone (this is sometimes injected into a vein at a high dose to treat various inflammatory or allergic conditions).

When Sinthrome is prescribed in combination with these drugs, more frequent monitoring (including blood tests) will be needed.

Other medicines that may increase the activity of Sinthrome such as:

  • allopurinol or sulfinpyrazone - for the treatment of gout and to lower uric acid levels
  • anabolic steroids - used as replacement therapy
  • androgens such as testosterone and mesterolone - used as replacement therapy
  • anti-arrhythmic agents such as amiodarone and quinidine - medicines for an irregular heartbeat
  • antibiotics (e.g. erythromycin, clarithromycin, tetracyclines, neomycin, chloramphenicol, amoxicillin, co-amoxiclav, some cephalosporins, some fluoroquinolones such as ciprofloxacin, norfloxacin and ofloxacin) - medicines used against infections
  • viloxazine and selective serotonin re-uptake inhibitors such as citalopram, fluoxetine, sertraline and paroxetine - used to treat anxiety and depression
  • clofibrate and related substances (e.g. fenofibrate, gemfibrozil) - medicines used against high cholesterol
  • disulfiram - for alcohol dependence
  • etacrynic acid - for water retention or high blood pressure
  • glucagon - used to treat low blood sugar levels
  • imidazole derivatives (e.g. metronidazole, and even when administered locally, like econazole, fluconazole, ketoconazole and miconazole) - a medicine used against infection
  • tramadol - a strong pain killer
  • tamoxifen - for breast cancer and fertility
  • proton pump inhibitors (e.g. omeprazole) – used to treat acid reflux, stomach or intestinal ulcers uptake inhibitors such as citalopram, fluoxetine, sertraline and paroxetine - used to treat anxiety and depression
  • paracetamol – a medicine used for pain
  • sulfonamides such as co-trimoxazole - used to treat infections
  • sulphonylureas such as tolbutamide, chlorpropamide and glibenclamide - oral medicines for diabetes
  • thyroid hormones such as levothyroxine or dextrothyroxine - used to treat an underactive thyroid
  • statins such as atorvastatin, fluvastatin and simvastatin - used to lower blood cholesterol levels
  • antineoplastics such as 5-fluorouracil - for breast, gastrointestinal and skin cancer
  • H2-agonists such as cimetidine or ranitidine - used to treat stomach or intestinal ulcers
  • plasminogen activators (e.g. urokinase; streptokinase and alteplase, thrombin inhibitors (e.g. argatroben) - medicines used to breakdown blood clots during heart stroke
  • prokinetic agents (e.g. cisapride) - medicines used to speed up gastric emptying
  • antacids (e.g. magnesium hydroxide) - medicines used against stomach acidity.
  • glucosamine (for osteoarthritis) may increase the effect of Sinthrome.

Medicines that may decrease the effect of Sinthrome such as:

  • aminoglutethimide - used to treat cancer or Cushing’s syndrome
  • mercaptopurine – used to treat cancer or autoimmune diseases (a type of diseases when your immune system attacks your own cells)
  • protease inhibitors such as ritonavir or nelfinavir - used to treat HIV
  • azathioprine – used after organ transplantation or for chronic inflammatory and autoimmune diseases
  • barbiturates such as sodium amytal or phenobarbital and carbamazepine - for epilepsy or to help you sleep
  • vitamin E
  • medicines known to increase the activity of some liver enzymes (i.e., CYP2C9, CYP2C19 or CYP3A4) – ask your doctor or pharmacist if you are not sure if any of your medicines has such effect.
  • oral contraceptives such as femodene, logynon and cilest - for birth control
  • rifampicin - medicine used against infection
  • thiazide diuretics (e.g., bendroflumethiazide or metolazone) - medicines used to treat water retention and high blood pressure
  • corticosteroids such as prednisolone - steroids used to treat inflammatory bowel disease, arthritis and certain skin conditions
  • St John’s Wort - for depression
  • cholestyramine - medicine used against high cholesterol levels
  • griseofulvin - used to treat fungal infections.
  • antineoplastic drugs (e.g. azathioprine, 6-mercaptopurine)
  • vitamin K (an increase in the amount of your vitamin K intake could reduce the effect of acenocoumarol

Medicines that may either increase or decrease the effects of Sinthrome:

  • protease inhibitors (e.g. indinavir, nelfinavir, ritonavir, saquinavir) – medicines used to treat HIV infection.
  • methylprednisolone, a corticosteroid used to treat various inflammatory conditions.

Effects of Sinthrome on other medicines

  • Sinthrome may increase the risk of toxicity by hydantoin derivatives such as phenytoin - medicines used to treat epilepsy.
  • Sinthrome may enhance the blood sugar lowering effect of antidiabetic medicines such as glibenclamide or glimepiride.

Sinthrome with food, drink and alcohol

Be careful when drinking alcohol as it may affect how Sinthrome thins your blood. Check with your doctor first.

You should avoid drinking cranberry juice or taking other cranberry products, such as capsules or concentrates as this could mean you do not receive the correct amount of acenocoumarol.


If you are 65 years or older you may be more sensitive to the effects of Sinthrome and so need more frequent check-ups. You may also need lower doses.

Children and adolescents

Experience with Sinthrome in children and adolescents is limited and so these patients need more frequent check-ups (see Section 3).

Pregnancy, breast-feeding and fertility

Do NOT take Sinthrome if you are pregnant. Sinthrome, like other anticoagulants can cause serious harm to your baby. Tell your doctor if you are pregnant or trying to become pregnant. Your doctor will discuss with you the potential risk of taking Sinthrome during pregnancy.

The decision to breast-feed while taking Sinthrome should be carefully considered with your doctor. You and your child may require blood tests if you are breast-feeding while you are taking Sinthrome. However, as a precaution, your doctor should prescribe vitamin K to your child to prevent their blood from being thinned.

It is not known whether Sinthrome can affect your fertility.

If you are of child bearing age, a pregnancy test may be done by your doctor to rule out pregnancy before you are given Sinthrome. You should use birth control while taking Sinthrome.

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Driving and using machines

Sinthrome has no influence on the ability to drive or use machines. However, you are advised to keep your anticoagulant card with you.

Sinthrome contain lactose

If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor or pharmacist before taking this medicinal product.

3. How to take Sinthrome

Always take Sinthrome exactly as your doctor has told you to. Check with your doctor or pharmacist if you are not sure.

Sinthrome should be taken as a single dose at the same time every day. Swallow your tablets whole with a drink of water.

Your doctor will arrange regular blood tests during treatment with Sinthrome to check on how fast your blood is clotting. This will help the doctor decide on your dose.

The dose of Sinthrome will vary from patient to patient and from day to day. The following can be used as a guide:

Adults and elderly:

The usual starting dose is between 2 mg/day to 4 mg/day without administration of a loading dose. Treatment can be started with a loading dose regimen, usually 6 mg on the first day followed by 4 mg on the second day.

Elderly patients, patients with liver disease or severe heart failure (which slows blood flow in the liver and may cause its injury) or malnourished patients may need lower doses.

Use in children and adolescents:

Experience with blood thinning medicines including Sinthrome in children and adolescents is limited. If Sinthrome is used in children or adolescents, blood should be tested more often, to see how well the medicine is working.

Tell your doctor or dentist or pharmacist at every visit that you are using Sinthrome.

If you take more Sinthrome than you should

If you accidentally take too many tablets, or someone else takes any of your medicine, you should tell your doctor immediately or contact the nearest accident and emergency department. The symptoms of overdose differ between people. They may appear 1 to 5 days after taking the medicine and include nosebleeds, bleeding from the gums, vomiting or coughing blood, blood in the urine, bloody or black tarry stools, genital bleeding, abundant menstrual bleeding, large bruises, or bleeding into the joints which causes tightness, swelling, and pain. Your heartbeat may speed up, your blood pressure may drop making you feel dizzy, and your skin may seem pale, cold and sweaty. You may experience sickness, vomiting, diarrhoea and abdominal pains. You may require blood tests to monitor your condition and treatment may be required. Show any left-over medicines or the empty packet to the doctor.

If you forget to take Sinthrome

Do not worry. If you forget to take a dose, take it as soon as possible, unless it is almost time to take the next dose. Do NOT take a double dose. Then go on as before.

If you stop taking Sintrome

If you have any questions on the use of this medicine, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, Sinthrome can cause side effects, although not everyone gets them.

Tell your doctor straight away if you have any of the following side effects:

Common (may affect up to 1 in 10 people):

  • bleeding:
    • bleeding from the gums, unexplained bruising or nosebleeds, heavy periods, heavy bleeding from cuts or wounds
    • bleeding from various organs: stomach, intestines, gallbladder (abdominal pain, vomiting blood, bloody or black tarry stools), urinary tract (backache, blood in the urine), brain (dizziness, severe headache, weakness in an arm or leg, blurred vision), and eyes (visible pool of blood)

Rare (may affect up to 1 in 1000 people):

  • allergic (hypersensitivity) reaction in the form of hives, skin rash, inflammation, itching, and fever
  • loss of appetite
  • feeling or being sick
  • vomiting
  • unusual hair loss

Very rare (may affect up to 1 in 10,000 people):

  • inflammation of blood vessels (vasculitis) which may cause bruising or bleeding under the skin
  • skin necrosis (tissue death) with blistering of the skin with or without scars, usually in areas of thighs, buttocks or breasts. This condition is usually associated with congenital deficiency of some proteins in blood
  • liver injury which may cause jaundice, stomach pain, swelling, and fatigue

Frequency not known: A painful skin rash. Sinthrome can cause a serious rare skin condition called calciphylaxis that can start with a painful skin rash but can lead to serious complications. This adverse reaction occurs most often in patients with chronic kidney disease or something wrong with the levels of calcium, albumin, phosphate, or certain proteins, in their blood. Condition of having a lower-than-normal number of red blood cells or reduced haemoglobin (Anaemia).

Reporting of side effects

If youget any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.

5. How to store Sinthrome

Keep this medicine out of the sight and reach of children.

Do not take Sinthrome after the expiry date which is stated on the carton after EXP. The expiry date refers to the last day of that month.

If your doctor decides to stop your treatment, return any unused medicine to the pharmacist. Only keep it if your doctor tells you to.

Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

6. Contents of the pack and other information
What Sinthrome contains

The active substance is acenocoumarol 1mg. This is the new name for nicoumalone. The ingredient itself has not changed.

The other excipients are: aerosol 200 (silica aerogel), lactose, hypromellose, magnesium stearate, maize starch and talc.

What Sinthrome looks like and contents of the pack

Sinthrome tablets are white, round, flat tablets with slightly bevelled edges, with “CG” imprinted on one side and “AA” on the other. They come in blister packs of 100 tablets.

Marketing Authorisation Holder and Manufacturer

Marketing Authorisation Holder

Norgine Pharmaceuticals Limited
Norgine House
Widewater Place
Moorhall Road


Rovi Pharma Industrial Services, S.A.
Vía Complutense, 140
Alcalá de Henares

The information in this leaflet applies only to Sinthrome. If you have any questions or you are not sure about anything, ask your doctor or a pharmacist.

This leaflet was last revised in October 2022

Sinthrome is a registered trademark of Novartis Pharmaceuticals Limited

Norgine Limited
Company image
Norgine House, Widewater Place, Moorhall Road, Harefield, Middlesex, UB9 6NS
+44 (0) 1895 826 606
Medical Information e-mail
[email protected]
Stock Availability
[email protected]