Prof. Alessio Redaelli

Aesthetic Medicine
Specialist in Vascular Surgery

Anticoagulant therapy (OAT) for the phlebothrombosis and prevention of emboligene diseases

The oral anticoagulant therapy is indicated in all those pathological conditions in which there is a risk of thromboembolism, which is when there is the possibility that a thrombus, especially venous, can occlude an important artery, causing very serious problems.

In fact there are some pathologies that can increase the formation of blood clots that, detaching, can follow the blood stream and then acutely occlude a peripheral vessel.

Sometimes there is the risk that an artery occludes.

Some other times the risk of thrombosis can be prevented after having inserted foreign materials, as prosthesis or by pass, in the body.

In particular I remind the atrial fibrillation, all the pathologies of the cardiac rhythm, phlebitis especially in deep veins, or in any other body districts.

But a lot of operations, especially on the heart valves can increase the risk of formation of thrombus and then be an indication of the OAT, acronym that means:

Oral Anticoagulant Therapy.


The OAT, which should not be confused with the antiplatelet therapy, increases the blood clotting time.

Basically the blood clots less, and it takes more time. In this way the possible formation of thrombus, the possibility to clot, is reduced. This decreases the risk of embolism.

In view of this anticoagulation, however, the risk of bleeding is normally very low.


In Italy only two medicines are authorized:

  • – Sintrom (4 mg and 1 mg) – acenocoumarol
  • – Coumadin (5 mg) – warfarin

This medicines, sold in every pharmacies according to the National Health System, act very individually. In fact every patient needs a personalized dosage, as often happens with  medicines. For this reason, patients have to take the medicines with their own doctor, who has to be an expert of this pharmacological mechanism. Medicine can be taken once a day, better if not during the meal, late in the afternoon.


The action of these two medicines is measured with extreme precision with two blood exams: the percentage of Prothrombin Activity (%AP) and the INR (International Normalized Ratio).

Basically the more we take the medicine, the more the percentage of Prothrombin reduces and the INR increases.

The best percentage of prothrombin in a patient under therapy should stay between 25 and 35%.

The best INR in a patient under anticoagulant therapy should be between 2 and 3.

It has to be highlighted that in some pathology the anticoagulation can be higher, for prevention, while in other pathologies can be less. For example, in the prevention after an implant of cardiac prosthesis and after a heart attack of the myocardium, the INR has to be between 3 and 4, and even 5.

Instead, after phlebitis, pulmonary embolism or Atrial Fibrillation, the INR has to be between 2 and 3.

However, always refer to the doctor, who will advice you for the best.

The exam has to be repeated for the first time even weekly, while when the result is stabilized, it can be repeated every month. But do not think that when the result is stabilized, you do not have to do it anymore: in fact, sometime, it can alter roughly, for seasonal changes, for intercurrent diseases or for medicines that we are taking. So, in my opinion, the INR should be under control, at least every month.

It is better to control the INR and the %AP in an authorized center so the values remain the same all the time. In fact, there can be small differences between a laboratory and another one.



No food should be considered prohibited. So a varied diet preserves us from any risk. However it is better not to assume some foods in excessive quantities, such us:

– parsley – Savoy cabbage – broccoli – spinach – cabbages – lettuce and any vegetable with green leaf – asparagus, lentils and peas (should not be taken in excessive quantities).

But as I told you, do not cross your bridges. Just do not eat too much of them.

Pay also attention to herbal tea and infusion that sometimes can interfere with this therapy.

Remember that the quantity of alcohol should be limited, especially hard liquors. A glass of wine every meal is permitted, only if it is good!


Many medicines interfere with the coagulation and can increase and decrease the INR.

I remind you that aspirins and anti-inflammatory medicine can increase the anticoagulation of blood. However, in every case the patient should always inform the doctor who is giving a new therapy that you are on Oral Anticoagulant Therapy, and remind it even to your own doctor, even if he has taken care of you for long time: he also gets old and can forget about it.

I personally execute always a gastric protection with pantoprazole, that I remind you, is the only gastric protector that has not interferences with the coagulation of blood and with oral anticoagulant medicines.


Nothing happens! Pay attention that the INR can vary. So control it with more frequency. Do always the Anti-influential Vaccination and remember to take preventive actions to avoid seasonal diseases.


You have to know you are lucky, because you live in a time where there are very advanced therapies. Trust your doctor and fill in your dosage form not to make mistakes that can expose you to useless risk.