Nach den aktuellen Leitlinien kardiologischer und neurologischer Fachgesellschaften
werden die neuen oralen Antikoagulanzien gegenüber Vitamin-K-Antagonisten bevorzugt
empfohlen. Die aktuellen Registerdaten bestätigen die in den Zulassungsstudien gewonnenen
Daten einer gegenüber Vitamin-K-Antagonisten höheren Sicherheit und mindestens vergleichbaren
Effektivität. Differenzialtherapeutische Vergleiche zwischen den 4 NOAKs sind bei
unterschiedlichen Patientenkollektiven in den Zulassungsstudien nur bedingt zulässig.
Differenzialtherapeutisch kommen für die Verordnung der NOAKs Aspekte, wie die renale
Elimination bei eingeschränkter Nierenfunktion, Einmal- oder Zweimalgabe, Verfügbarkeit
eines Antidots, vorbestehende gastrointestinale Blutungsanamnese und persönliche Erfahrungswerte
in Betracht.
According to recommendations in the current guidelines of the professional societies
for cardiology and neurology, the new oral anticoagulants are to be preferred over
vitamin K antagonists. In a metaanalysis of large phase III trials the new oral anticoagulants
were found to reduce the risks for stroke and systemic embolism by 19% in comparison
with vitamin K antagonists (p < 0,0001). Furthermore, the new oral anticoagulants
were altogether shown to exhibit a lower overall mortality (p = 0,0003) as well as
a lower incidence of intracranial bleeding (p < 0,0001) with, however, a higher incidence
of gastrointestinal bleeding (p = 0,04). The mechanism responsible for the increased
rates of gastrointestinal bleeding for dabigatran and the factor Xa inhibitors is
not completely clear as yet. Dabigatran and, to a lesser extent, the factor Xa inhibitors
are partially excreted through the intestine by a P-glycoprotein transport system
so that, possibly an elevated concentration of the active principles is present in
the intestinal mucous membranes. Dabigatran exhibits a low bioavailability (7,2 %)
and is activated directly in the gastrointestinal tract, thus a prolonged contact
time of the active components in the intestine can lead to a locally slightly increased
tendency for bleeding. In contrast, warfarin with a higher bioavailability is more
completely absorbed and the not absorbed portions are not active.
Current register data confirm the findings obtained in the approval trials concerning
a higher safety and an at least equivalent efficacy as compared with vitamin K antagonists.
Differential therapeutic comparisons of four new oral anticoagulants in differing
patient collectives in the appoval trials are of only limited relevance. For the prescription
of the new oral anticoagulants, aspects such as renal elimination in cases of renal
insufficiency, once or twice daily administration, availability of an antidote, preexisting
history of gastrointestinal bleeding and personal experience should be considered
from the differential therapeutic point of view.
Key words
Anticoagulation - new oral anticoagulants - atrial fibrillation - stroke - embolism
- gastrointestinal bleeding - register data
