Drug

Arixtra®

Alternative drug: Marcumar
Diseases in which Arixtra® is used:
- thrombosis
- Thrombosis prophylaxis
- Pulmonary embolism

Synonyms in a broader sense

Active ingredient name: Fondaparinux

Fondaparinux sodium
synthetic fondaparinux
Anticoagulants
Factor Xa inhibitor

Explanation / definition

Arixtra® is a drug for direct Inhibition of blood clottingIn medical parlance, the drug belongs to the group of direct Anticoagulants.
Arixtra® is used in the preventive treatment of Thrombosis and Embolisms, so the formation of Blood clots and Vascular occlusions prevent (Thrombosis prophylaxis).
Frequently becomes Arixtra® therefore used in the context of major surgical interventions on the lower extremities, for example when implanting a Knee prosthesis or Hip prosthesis.

Effect / mode of action

The active ingredient of the drug Arixtra® is the synthetic one Fondaparinux. Chemically, it has a similarity to the anticoagulant Heparin on.
Fondaparinux intervenes in the coagulation mechanism by causing the Coagulation factor Xa selectively inhibits.

The process of blood clotting consists of two phases:

primary hemostasis
and
secondary hemostasis

The primary hemostasis initially leads within 1-3 minutes to Hemostasis and forming one loose wound closure.
The secondary hemostasis makes sure one Fibrin mesh trains and the Wound closure is stabilized.
This happens within a period of 6-10 minutes.
Secondary hemostasis is controlled by coagulation factors; Factor Xa initiates the final stretch of the plasmatic coagulation.
He divides Prothrombin to Thrombin, the activated Factor IIa. Fibrin is in turn activated via thrombin. This is done using Factor XIII cross-linked and stabilizes the wound closure, a thrombus was created.

Will now Factor Xa by Fondaparinux inhibited, can Blood coagulation cascade no longer run properly.
Thrombin can no longer be activated and the stable blood clot does not form.

Dosage / administration of Arixtra®

Arixtra® is prescription only and is distributed by pharmacies as a clear solution for injection in pre-filled syringes (0.5 ml).
Depending on the application, there are Arixtra® in cans of:

1.5mg
2.5 mg
5 mg
7.5 mg
and
10 mg

1.5-2.5 mg is the standard dose as part of orthopedic surgery and for the prevention of superficial blood clots, while the higher doses are more for the therapy of deep vein thrombosis (DVT) and Pulmonary embolism can be used.

application

Arixtra® 2.5 mg should take around six hours after the orthopedic procedure under the skin The injection is usually made into the subcutaneous fatty tissue of the abdomen.
The Daily dose amounts 2.5 mg and should be done until the risk for postoperative thrombosis or embolism has decreased usually 5-9 days long.
Even when treating a superficial vein thrombosis is given once a day and held at this dose for approximately 30 to 45 days.
Patients are also given 2.5 mg unstable angina pectoris (“Chest tightness” is usually based on a narrowing of the Coronary arteries, triggered by arteriosclerosis) or diagnosed Heart attack administered, here the first dose is administered intravenously or by drip infusion. The duration of treatment in this case is at least one week.

Arixtra® 7.5 mg is administered to patients for the treatment of a deep vein thrombosis (DVT) or a pulmonary embolism (a blood clot that has been dragged along and thus dangerous occlusion in vessels supplying the lungs) once a day. Again, the daily injection should be given for at least a week.

Special instructions for use / side effects

By the increased risk of bleeding and those that appear more and more with age Kidney dysfunction Treatment of elderly patients (over 75 years of age) should be carried out with caution.
Arixtra® also must not be used in children and adolescents under 17 years of age.
Patient with a low body weight (<50 kg body weight) and patients with congenital or acquired coagulation disorders also have one higher risk of bleeding and should be handled very controlled.
For patients with known Renal dysfunction is the Creatinine Clearance an important parameter for assessing the risk of possible bleeding.
At a Creatinine Clearance from 20-50 ml / min should just be careful with Arixtra® 1.5 mg treated and a Creatinine clearance < 20 ml / min completely excludes the use of the drug (Contraindication).
In the case of severe Liver dysfunction should be the active ingredient Fondaparinux should only be used with caution as there is also an increased risk of bleeding for the patient.

During one pregnancy or in the Lactation should be medication with Arixtra® if possible not be done because there is insufficient experience.

Please also read our topic: Medication during pregnancy

Drug interactions

Various Medicationthat increase the risk of bleeding should not be taken with Arixtra® administered.
The following should be mentioned in this context:

Desirudin
Heparin
Fibrinolytics (e.g. urokinase, streptokinase)
or
GP IIb / IIIa receptor antagonists (e.g. abciximab, tirofiban).

Non-steroidal pain relievers with anti-inflammatory effects and Platelets-Aggregation inhibitors such as:

Clopidogrel
Ticlopidine
or
Acetylsalicylic acid

should go along with Arixtra® can only be administered under strict control.
When switching the patient to oral anticoagulants how Marcumar therapy should be with Arixtra® should not be stopped until the patient's INR has been set correctly.

Contraindications

Arixtra® should not be used if the active ingredient is known Fondaparinux or one of its components in the patient Hypersensitivity evokes.
In addition, is currently available Bleeding, one bacterial infection of the Lining of the heart (endocarditis) or one severe renal impairment (Creatinine clearance <20ml / min) from treatment with Arixtra® to be foreseen.